Merge branch 'develop' into vfd_init_cleanup

131 files changed, 13055 insertions, 8266 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index e2fb000..a16cb08 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -756,6 +756,13 @@ if (BUILD_TESTING)
     mark_as_advanced (HDF5_TEST_FHEAP_VFD)
   endif ()
 
+  option (HDF5_TEST_VOL "Execute tests with different VOL connectors" OFF)
+  mark_as_advanced (HDF5_TEST_VOL)
+  if (HDF5_TEST_VOL)
+    option (HDF5_TEST_FHEAP_VOL "Execute fheap test with different VOL connectors" ON)
+    mark_as_advanced (HDF5_TEST_FHEAP_VOL)
+  endif ()
+
   option (HDF_TEST_EXPRESS "Control testing framework (0-3)" "0")
   mark_as_advanced (HDF_TEST_EXPRESS)
 
diff --git a/MANIFEST b/MANIFEST
index d840e73..cb006cc 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -489,7 +489,6 @@
 ./src/H5Apublic.h
 ./src/H5AC.c
 ./src/H5ACdbg.c
-./src/H5AClog.c
 ./src/H5ACmodule.h
 ./src/H5ACmpio.c
 ./src/H5ACpkg.h
@@ -519,6 +518,9 @@
 ./src/H5Cepoch.c
 ./src/H5Cimage.c
 ./src/H5Clog.c
+./src/H5Clog.h
+./src/H5Clog_json.c
+./src/H5Clog_trace.c
 ./src/H5Cmodule.h
 ./src/H5Cmpio.c
 ./src/H5Cpkg.h
@@ -894,6 +896,14 @@
 ./src/H5VLmodule.h
 ./src/H5VLnative.c
 ./src/H5VLnative.h
+./src/H5VLnative_attr.c
+./src/H5VLnative_dataset.c
+./src/H5VLnative_datatype.c
+./src/H5VLnative_file.c
+./src/H5VLnative_group.c
+./src/H5VLnative_link.c
+./src/H5VLnative_object.c
+./src/H5VLnative_private.h
 ./src/H5VLpassthru.c
 ./src/H5VLpassthru.h
 ./src/H5VLpkg.h
@@ -964,7 +974,6 @@
 ./test/dtypes.c
 ./test/dtransform.c
 ./test/earray.c
-./test/echo_vol.c
 ./test/efc.c
 ./test/enc_dec_plist.c
 ./test/enc_dec_plist_cross_platform.c
@@ -1012,6 +1021,7 @@
 ./test/gen_deflate.c
 ./test/gen_file_image.c
 ./test/gen_filespace.c
+./test/gen_filters.c
 ./test/gen_mergemsg.c
 ./test/gen_new_array.c
 ./test/gen_new_fill.c
@@ -1055,6 +1065,8 @@
 ./test/noencoder.h5
 ./test/none.h5
 ./test/ntypes.c
+./test/null_vol_connector.c
+./test/null_vol_connector.h
 ./test/ohdr.c
 ./test/objcopy.c
 ./test/page_buffer.c
@@ -1095,12 +1107,15 @@
 ./test/testlinks_env.sh.in
 ./test/test_filenotclosed.sh.in
 ./test/test_filter_plugin.sh.in
+./test/test_filters_le.h5
+./test/test_filters_be.h5
 ./test/testflushrefresh.sh.in
 ./test/testframe.c
 ./test/testhdf5.c
 ./test/testhdf5.h
 ./test/testlibinfo.sh.in
 ./test/test_usecases.sh.in
+./test/test_vol_plugin.sh.in
 ./test/testmeta.c
 ./test/testswmr.sh.in
 ./test/testvdsswmr.sh.in
@@ -1142,16 +1157,14 @@
 ./test/use_common.c
 ./test/use_disable_mdc_flushes.c
 ./test/use.h
-./test/vfd.c
-./test/vol.c
-./test/test_filters_le.h5
-./test/test_filters_be.h5
-./test/gen_filters.c
 ./test/vds.c
 ./test/vds_swmr.h
 ./test/vds_swmr_gen.c
 ./test/vds_swmr_reader.c
 ./test/vds_swmr_writer.c
+./test/vfd.c
+./test/vol.c
+./test/vol_plugin.c
 
 ./test/testfiles/err_compat_1
 ./test/testfiles/err_compat_2
@@ -1282,6 +1295,7 @@
 ./testpar/t_span_tree.c
 ./testpar/t_init_term.c
 ./testpar/testpar.h
+./testpar/testpflush.sh.in
 ./testpar/testphdf5.c
 ./testpar/testphdf5.h
 
@@ -2884,6 +2898,8 @@
 ./java/src/jni/h5sImp.h
 ./java/src/jni/h5tImp.c
 ./java/src/jni/h5tImp.h
+./java/src/jni/h5vlImp.c
+./java/src/jni/h5vlImp.h
 ./java/src/jni/h5zImp.c
 ./java/src/jni/h5zImp.h
 
@@ -3122,6 +3138,7 @@
 ./java/test/testfiles/JUnit-TestH5Tparams.txt
 ./java/test/testfiles/JUnit-TestH5Tbasic.txt
 ./java/test/testfiles/JUnit-TestH5T.txt
+./java/test/testfiles/JUnit-TestH5VL.txt
 ./java/test/testfiles/JUnit-TestH5Z.txt
 ./java/test/h5ex_g_iterate.orig
 ./java/test/TestH5.java
@@ -3159,6 +3176,7 @@
 ./java/test/TestH5Tparams.java
 ./java/test/TestH5Tbasic.java
 ./java/test/TestH5T.java
+./java/test/TestH5VL.java
 ./java/test/TestH5Z.java
 ./java/test/TestAll.java
 
@@ -3203,6 +3221,7 @@
 ./config/cmake/UseJavaSymlinks.cmake
 ./config/cmake/userblockTest.cmake
 ./config/cmake/vfdTest.cmake
+./config/cmake/volTest.cmake
 ./config/cmake/wait_H5Tinit.cmake
 
 ./config/cmake_ext_mod/ConfigureChecks.cmake
@@ -3243,6 +3262,7 @@
 ./c++/src/CMakeLists.txt
 ./c++/test/CMakeLists.txt
 ./c++/test/CMakeTests.cmake
+./c++/test/CMakeVFDTests.cmake
 ./examples/CMakeLists.txt
 ./examples/CMakeTests.cmake
 ./examples/run-all-ex.sh
@@ -3282,10 +3302,12 @@
 ./test/CMakeLists.txt
 ./test/CMakeTests.cmake
 ./test/CMakeVFDTests.cmake
+./test/CMakeVOLTests.cmake
 ./test/flushrefreshTest.cmake
 ./test/ShellTests.cmake
 ./testpar/CMakeLists.txt
 ./testpar/CMakeTests.cmake
+./testpar/CMakeVFDTests.cmake
 ./tools/CMakeLists.txt
 ./tools/lib/CMakeLists.txt
 ./tools/src/CMakeLists.txt
@@ -3318,6 +3340,7 @@
 ./tools/src/h5repack/CMakeLists.txt
 ./tools/test/h5repack/CMakeLists.txt
 ./tools/test/h5repack/CMakeTests.cmake
+./tools/test/h5repack/CMakeVFDTests.cmake
 ./tools/src/h5stat/CMakeLists.txt
 ./tools/test/h5stat/CMakeLists.txt
 ./tools/test/h5stat/CMakeTests.cmake
diff --git a/c++/test/CMakeTests.cmake b/c++/test/CMakeTests.cmake
index 6de801e..02bff3e 100644
--- a/c++/test/CMakeTests.cmake
+++ b/c++/test/CMakeTests.cmake
@@ -47,55 +47,12 @@ else ()
 endif ()
 set_tests_properties (CPP_testhdf5 PROPERTIES DEPENDS CPP_testhdf5-clear-objects)
 
-if (HDF5_TEST_VFD)
-
-  set (VFD_LIST
-      sec2
-      stdio
-      core
-      split
-      multi
-      family
-  )
-
-  if (DIRECT_VFD)
-    set (VFD_LIST ${VFD_LIST} direct)
-  endif ()
-
-  macro (ADD_VFD_TEST vfdname resultcode)
-    if (NOT HDF5_ENABLE_USING_MEMCHECKER)
-      file (MAKE_DIRECTORY "${PROJECT_BINARY_DIR}/${vfdname}")
-      add_test (
-          NAME CPP_VFD-${vfdname}-cpp_testhdf5-clear-objects
-          COMMAND    ${CMAKE_COMMAND}
-              -E remove
-                  tattr_basic.h5
-                  tattr_compound.h5
-                  tattr_dtype.h5
-                  tattr_multi.h5
-                  tattr_scalar.h5
-                  tfattrs.h5
-                  titerate.h5
-      )
-      add_test (
-        NAME CPP_VFD-${vfdname}-cpp_testhdf5
-        COMMAND "${CMAKE_COMMAND}"
-            -D "TEST_PROGRAM=$<TARGET_FILE:cpp_testhdf5>"
-            -D "TEST_ARGS:STRING="
-            -D "TEST_VFD:STRING=${vfdname}"
-            -D "TEST_EXPECT=${resultcode}"
-            -D "TEST_OUTPUT=cpp_testhdf5"
-            -D "TEST_FOLDER=${PROJECT_BINARY_DIR}/${vfdname}"
-            -P "${HDF_RESOURCES_DIR}/vfdTest.cmake"
-      )
-      set_tests_properties (CPP_VFD-${vfdname}-cpp_testhdf5 PROPERTIES DEPENDS CPP_VFD-${vfdname}-cpp_testhdf5-clear-objects)
-      set_tests_properties (CPP_VFD-${vfdname}-cpp_testhdf5 PROPERTIES TIMEOUT 30)
-    endif ()
-  endmacro ()
-
-  # Run test with different Virtual File Driver
-  foreach (vfd ${VFD_LIST})
-    ADD_VFD_TEST (${vfd} 0)
-  endforeach ()
+##############################################################################
+##############################################################################
+###                         V F D   T E S T S                              ###
+##############################################################################
+##############################################################################
 
+if (HDF5_TEST_VFD)
+  include (CMakeVFDTests.cmake)
 endif ()
diff --git a/c++/test/CMakeVFDTests.cmake b/c++/test/CMakeVFDTests.cmake
new file mode 100644
index 0000000..996a20f
--- /dev/null
+++ b/c++/test/CMakeVFDTests.cmake
@@ -0,0 +1,65 @@
+#
+# Copyright by The HDF Group.
+# All rights reserved.
+#
+# This file is part of HDF5.  The full HDF5 copyright notice, including
+# terms governing use, modification, and redistribution, is contained in
+# the COPYING file, which can be found at the root of the source code
+# distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.
+# If you do not have access to either file, you may request a copy from
+# help@hdfgroup.org.
+#
+
+##############################################################################
+##############################################################################
+###           T E S T I N G                                                ###
+##############################################################################
+##############################################################################
+  set (VFD_LIST
+      sec2
+      stdio
+      core
+      split
+      multi
+      family
+  )
+
+  if (DIRECT_VFD)
+    set (VFD_LIST ${VFD_LIST} direct)
+  endif ()
+
+  macro (ADD_VFD_TEST vfdname resultcode)
+    if (NOT HDF5_ENABLE_USING_MEMCHECKER)
+      file (MAKE_DIRECTORY "${PROJECT_BINARY_DIR}/${vfdname}")
+      add_test (
+          NAME CPP_VFD-${vfdname}-cpp_testhdf5-clear-objects
+          COMMAND    ${CMAKE_COMMAND}
+              -E remove
+                  tattr_basic.h5
+                  tattr_compound.h5
+                  tattr_dtype.h5
+                  tattr_multi.h5
+                  tattr_scalar.h5
+                  tfattrs.h5
+                  titerate.h5
+      )
+      add_test (
+        NAME CPP_VFD-${vfdname}-cpp_testhdf5
+        COMMAND "${CMAKE_COMMAND}"
+            -D "TEST_PROGRAM=$<TARGET_FILE:cpp_testhdf5>"
+            -D "TEST_ARGS:STRING="
+            -D "TEST_VFD:STRING=${vfdname}"
+            -D "TEST_EXPECT=${resultcode}"
+            -D "TEST_OUTPUT=cpp_testhdf5"
+            -D "TEST_FOLDER=${PROJECT_BINARY_DIR}/${vfdname}"
+            -P "${HDF_RESOURCES_DIR}/vfdTest.cmake"
+      )
+      set_tests_properties (CPP_VFD-${vfdname}-cpp_testhdf5 PROPERTIES DEPENDS CPP_VFD-${vfdname}-cpp_testhdf5-clear-objects)
+      set_tests_properties (CPP_VFD-${vfdname}-cpp_testhdf5 PROPERTIES TIMEOUT 30)
+    endif ()
+  endmacro ()
+
+  # Run test with different Virtual File Driver
+  foreach (vfd ${VFD_LIST})
+    ADD_VFD_TEST (${vfd} 0)
+  endforeach ()
diff --git a/config/cmake/ConfigureChecks.cmake b/config/cmake/ConfigureChecks.cmake
index 6d1e3ce..459346e 100644
--- a/config/cmake/ConfigureChecks.cmake
+++ b/config/cmake/ConfigureChecks.cmake
@@ -28,15 +28,6 @@ if (HDF5_STRICT_FORMAT_CHECKS)
 endif ()
 MARK_AS_ADVANCED (HDF5_STRICT_FORMAT_CHECKS)
 
-#-----------------------------------------------------------------------------
-# Option for --enable-metadata-trace-file
-#-----------------------------------------------------------------------------
-option (HDF5_METADATA_TRACE_FILE "Enable metadata trace file collection" OFF)
-if (HDF5_METADATA_TRACE_FILE)
-  set (${HDF_PREFIX}_METADATA_TRACE_FILE 1)
-endif ()
-MARK_AS_ADVANCED (HDF5_METADATA_TRACE_FILE)
-
 # ----------------------------------------------------------------------
 # Decide whether the data accuracy has higher priority during data
 # conversions.  If not, some hard conversions will still be prefered even
diff --git a/config/cmake/H5pubconf.h.in b/config/cmake/H5pubconf.h.in
index 2ddb740..c42d93a 100644
--- a/config/cmake/H5pubconf.h.in
+++ b/config/cmake/H5pubconf.h.in
@@ -466,9 +466,6 @@
 /* Define to enable internal memory allocation sanity checking. */
 /* #cmakedefine H5_MEMORY_ALLOC_SANITY_CHECK @H5_MEMORY_ALLOC_SANITY_CHECK@ ** Define in CMakeLists.txt */
 
-/* Define if the metadata trace file code is to be compiled in */
-#cmakedefine H5_METADATA_TRACE_FILE @H5_METADATA_TRACE_FILE@
-
 /* Define if we can violate pointer alignment restrictions */
 #cmakedefine H5_NO_ALIGNMENT_RESTRICTIONS @H5_NO_ALIGNMENT_RESTRICTIONS@
 
diff --git a/config/cmake/libhdf5.settings.cmake.in b/config/cmake/libhdf5.settings.cmake.in
index 6a489e7..9a534df 100644
--- a/config/cmake/libhdf5.settings.cmake.in
+++ b/config/cmake/libhdf5.settings.cmake.in
@@ -79,7 +79,6 @@ Parallel Filtered Dataset Writes: @PARALLEL_FILTERED_WRITES@
                      API Tracing: @HDF5_ENABLE_TRACE@
             Using memory checker: @HDF5_ENABLE_USING_MEMCHECKER@
  Memory allocation sanity checks: @HDF5_MEMORY_ALLOC_SANITY_CHECK@
-             Metadata trace file: @METADATATRACEFILE@
           Function Stack Tracing: @HDF5_ENABLE_CODESTACK@
        Strict File Format Checks: @HDF5_STRICT_FORMAT_CHECKS@
     Optimization Instrumentation: @HDF5_Enable_Instrument@
diff --git a/config/cmake/volTest.cmake b/config/cmake/volTest.cmake
new file mode 100644
index 0000000..27da8a5
--- /dev/null
+++ b/config/cmake/volTest.cmake
@@ -0,0 +1,76 @@
+#
+# Copyright by The HDF Group.
+# All rights reserved.
+#
+# This file is part of HDF5.  The full HDF5 copyright notice, including
+# terms governing use, modification, and redistribution, is contained in
+# the COPYING file, which can be found at the root of the source code
+# distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.
+# If you do not have access to either file, you may request a copy from
+# help@hdfgroup.org.
+#
+# volTest.cmake executes a command and captures the output in a file. Command uses specified VOL.
+# Exit status of command can also be compared.
+
+# arguments checking
+if (NOT TEST_PROGRAM)
+  message (FATAL_ERROR "Require TEST_PROGRAM to be defined")
+endif ()
+if (NOT TEST_FOLDER)
+  message ( FATAL_ERROR "Require TEST_FOLDER to be defined")
+endif ()
+if (NOT TEST_VOL)
+  message (FATAL_ERROR "Require TEST_VOL to be defined")
+endif ()
+
+if (EXISTS ${TEST_FOLDER}/${TEST_OUTPUT})
+  file (REMOVE ${TEST_FOLDER}/${TEST_OUTPUT})
+endif ()
+
+if (EXISTS ${TEST_FOLDER}/${TEST_OUTPUT}.err)
+  file (REMOVE ${TEST_FOLDER}/${TEST_OUTPUT}.err)
+endif ()
+
+# if there is not an error reference file add the error output to the stdout file
+#if (NOT TEST_ERRREF)
+#  set (ERROR_APPEND 1)
+#endif ()
+
+message (STATUS "USING ${TEST_VOL} ON COMMAND: ${TEST_PROGRAM} ${TEST_ARGS}")
+
+set (ENV{HDF5_VOL_CONNECTOR} "${TEST_VOL}")
+
+# run the test program, capture the stdout/stderr and the result var
+execute_process (
+    COMMAND ${TEST_PROGRAM} ${TEST_ARGS}
+    WORKING_DIRECTORY ${TEST_FOLDER}
+    RESULT_VARIABLE TEST_RESULT
+    OUTPUT_FILE ${TEST_OUTPUT}.out
+    ERROR_FILE ${TEST_OUTPUT}.err
+    OUTPUT_VARIABLE TEST_OUT
+    ERROR_VARIABLE TEST_ERROR
+)
+
+message (STATUS "COMMAND Result: ${TEST_RESULT}")
+
+# if the .err file exists and ERRROR_APPEND is enabled
+if (ERROR_APPEND AND EXISTS ${TEST_FOLDER}/${TEST_OUTPUT}.err)
+  file (READ ${TEST_FOLDER}/${TEST_OUTPUT}.err TEST_STREAM)
+  file (APPEND ${TEST_FOLDER}/${TEST_OUTPUT}.out "${TEST_STREAM}")
+endif ()
+
+# if the return value is !=${TEST_EXPECT} bail out
+if (NOT "${TEST_RESULT}" STREQUAL "${TEST_EXPECT}")
+  if (NOT TEST_NOERRDISPLAY)
+    if (EXISTS ${TEST_FOLDER}/${TEST_OUTPUT}.out)
+      file (READ ${TEST_FOLDER}/${TEST_OUTPUT}.out TEST_STREAM)
+    message (STATUS "Output USING ${TEST_VOL}:\n${TEST_STREAM}")
+    endif ()
+  endif ()
+  message (FATAL_ERROR "Failed: Test program ${TEST_PROGRAM} exited != ${TEST_EXPECT}.\n${TEST_ERROR}")
+endif ()
+
+message (STATUS "COMMAND Error: ${TEST_ERROR}")
+
+# everything went fine...
+message ("Passed: The ${TEST_PROGRAM} program used vol ${TEST_VOL}")
diff --git a/config/cmake_ext_mod/runTest.cmake b/config/cmake_ext_mod/runTest.cmake
index 0bc2db0..026131b 100644
--- a/config/cmake_ext_mod/runTest.cmake
+++ b/config/cmake_ext_mod/runTest.cmake
@@ -93,12 +93,14 @@ if (EXISTS ${TEST_FOLDER}/${TEST_OUTPUT}.err)
   if (TEST_MASK_FILE)
     STRING(REGEX REPLACE "CurrentDir is [^\n]+\n" "CurrentDir is (dir name)\n" TEST_STREAM "${TEST_STREAM}")
   endif ()
+  # remove special output
+  string (REGEX REPLACE "^.*_pmi_alps[^\n]+\n" "" TEST_STREAM "${TEST_STREAM}")
 
   if (NOT ERROR_APPEND)
-    # append error output to the stdout output file
+    # write back to original .err file
     file (WRITE ${TEST_FOLDER}/${TEST_OUTPUT}.err "${TEST_STREAM}")
   else ()
-    # write back to original .err file
+    # append error output to the stdout output file
     file (APPEND ${TEST_FOLDER}/${TEST_OUTPUT} "${TEST_STREAM}")
   endif ()
 endif ()
@@ -121,6 +123,14 @@ endif ()
 
 message (STATUS "COMMAND Error: ${TEST_ERROR}")
 
+# remove special output
+file (READ ${TEST_FOLDER}/${TEST_OUTPUT} TEST_STREAM)
+string (FIND TEST_STREAM "_pmi_alps" "${TEST_FIND_RESULT}")
+if ("${TEST_FIND_RESULT}" GREATER "0")
+  string (REGEX REPLACE "^.*_pmi_alps[^\n]+\n" "" TEST_STREAM "${TEST_STREAM}")
+  file (WRITE ${TEST_FOLDER}/${TEST_OUTPUT} ${TEST_STREAM})
+endif ()
+
 # if the output file needs Storage text removed
 if (TEST_MASK)
   file (READ ${TEST_FOLDER}/${TEST_OUTPUT} TEST_STREAM)
@@ -144,7 +154,6 @@ if (TEST_MASK_ERROR)
     # the error stack remains in the .err file
     file (READ ${TEST_FOLDER}/${TEST_OUTPUT}.err TEST_STREAM)
   endif ()
-  string (REGEX REPLACE "^.*_pmi_alps[^\n]+\n" "" TEST_STREAM "${TEST_STREAM}")
   string (REGEX REPLACE "thread [0-9]*:" "thread (IDs):" TEST_STREAM "${TEST_STREAM}")
   string (REGEX REPLACE ": ([^\n]*)[.]c " ": (file name) " TEST_STREAM "${TEST_STREAM}")
   string (REGEX REPLACE " line [0-9]*" " line (number)" TEST_STREAM "${TEST_STREAM}")
diff --git a/config/conclude.am b/config/conclude.am
index 4655565..9da1da5 100644
--- a/config/conclude.am
+++ b/config/conclude.am
@@ -131,28 +131,43 @@ $(TEST_PROG_CHKEXE) $(TEST_PROG_PARA_CHKEXE) dummy.chkexe_:
                  echo "============================" > $${log}; \
               fi; \
               if test "X$(FORTRAN_API)" = "Xyes"; then \
-                 echo "Fortran API: Testing $(HDF5_DRIVER) $${tname} $(TEST_FLAGS)"; \
+                 echo "Fortran API: Testing $${tname} $(TEST_FLAGS)"; \
                  if test -n "$(REALTIMEOUTPUT)"; then \
-                    echo "Fortran API: $(HDF5_DRIVER) $${tname} $(TEST_FLAGS) Test Log" | tee -a $${log}; \
+                    echo "Fortran API: Test log for $${tname} $(TEST_FLAGS)" | tee -a $${log}; \
                  else \
-                    echo "Fortran API: $(HDF5_DRIVER) $${tname} $(TEST_FLAGS) Test Log" >> $${log}; \
+                    echo "Fortran API: Test log for $${tname} $(TEST_FLAGS)" >> $${log}; \
                  fi; \
               elif test "X$(CXX_API)" = "Xyes"; then \
-                 echo "C++ API: Testing $(HDF5_DRIVER) $${tname} $(TEST_FLAGS)"; \
+                 echo "C++ API: Testing $${tname} $(TEST_FLAGS)"; \
                  if test -n "$(REALTIMEOUTPUT)"; then \
-                    echo "C++ API: $(HDF5_DRIVER) $${tname} $(TEST_FLAGS) Test Log" | tee -a $${log};\
+                    echo "C++ API: Test log for $${tname} $(TEST_FLAGS)" | tee -a $${log};\
                  else \
-                    echo "C++ API: $(HDF5_DRIVER) $${tname} $(TEST_FLAGS) Test Log" >> $${log};\
+                    echo "C++ API: Test log for $${tname} $(TEST_FLAGS)" >> $${log};\
                  fi; \
               else \
-                 echo "Testing $(HDF5_DRIVER) $${tname} $(TEST_FLAGS)"; \
+                 echo "Testing: $${tname} $(TEST_FLAGS)"; \
                  if test -n "$(REALTIMEOUTPUT)"; then \
-                    echo "$(HDF5_DRIVER) $${tname} $(TEST_FLAGS) Test Log" | tee -a $${log}; \
+                    echo "Test log for $${tname} $(TEST_FLAGS)" | tee -a $${log}; \
                  else \
-                    echo "$(HDF5_DRIVER) $${tname} $(TEST_FLAGS) Test Log" >> $${log}; \
+                    echo "Test log for $${tname} $(TEST_FLAGS)" >> $${log}; \
                  fi; \
               fi; \
               if test -n "$(REALTIMEOUTPUT)"; then \
+                if test -n "$(HDF5_VOL_CONNECTOR)"; then \
+                  echo "VOL connector: $(HDF5_VOL_CONNECTOR)" | tee -a $${log}; \
+                fi; \
+                if test -n "$(HDF5_DRIVER)"; then \
+                  echo "Virtual file driver (VFD): $(HDF5_DRIVER)" | tee -a $${log}; \
+                fi; \
+              else \
+                if test -n "$(HDF5_VOL_CONNECTOR)"; then \
+                  echo "VOL connector: $(HDF5_VOL_CONNECTOR)" >> $${log}; \
+                fi; \
+                if test -n "$(HDF5_DRIVER)"; then \
+                  echo "Virtual file driver (VFD): $(HDF5_DRIVER)" >> $${log}; \
+                fi; \
+              fi; \
+              if test -n "$(REALTIMEOUTPUT)"; then \
                  echo "============================" | tee -a $${log}; \
               else \
                  echo "============================" >> $${log}; \
@@ -234,7 +249,7 @@ build-check-p: $(LIB) $(PROGS) $(chk_TESTS)
 	    echo "**** Hint ****";                                            \
 	    echo "Parallel test files reside in the current directory"        \
 	         "by default.";                                               \
-	    echo "Set HDF5_PARAPREFIX to use another directory. E.g.,";       \
+	    echo "Set HDF5_PARAPREFIX to use another directory. e.g.,";       \
 	    echo "    HDF5_PARAPREFIX=/PFS/user/me";                          \
 	    echo "    export HDF5_PARAPREFIX";                                \
 	    echo "    make check";                                            \
diff --git a/configure.ac b/configure.ac
index 0a1370f..eb32435 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2289,40 +2289,6 @@ case "X-$CODESTACK" in
 esac
 
 ## ----------------------------------------------------------------------
-## Check if they would like the metadata trace file code compiled in
-##
-AC_MSG_CHECKING([whether metadata trace file code is enabled])
-AC_ARG_ENABLE([metadata-trace-file],
-              [AS_HELP_STRING([--enable-metadata-trace-file],
-                              [Enable metadata trace file collection.
-                               [default=no]
-                              ])],
-              [METADATATRACEFILE=$enableval])
-
-## Set the default level.
-if test "X-$METADATATRACEFILE" = X- ; then
-  METADATATRACEFILE=no
-fi
-
-## Allow this variable to be substituted in
-## other files (src/libhdf5.settings.in, etc.)
-AC_SUBST([METADATATRACEFILE])
-
-case "X-$METADATATRACEFILE" in
-  X-yes)
-      AC_MSG_RESULT([yes])
-      AC_DEFINE([METADATA_TRACE_FILE], [1],
-                [Define if the metadata trace file code is to be compiled in])
-    ;;
-  X-no)
-      AC_MSG_RESULT([no])
-    ;;
-  *)
-      AC_MSG_ERROR([Unrecognized value: $METADATATRACEFILE])
-    ;;
-esac
-
-## ----------------------------------------------------------------------
 ## Enable tracing of the API
 ##
 AC_MSG_CHECKING([for API tracing]);
@@ -3443,7 +3409,9 @@ AC_CONFIG_FILES([src/libhdf5.settings
                  test/test_filenotclosed.sh
                  test/test_filter_plugin.sh
                  test/test_usecases.sh
+                 test/test_vol_plugin.sh
                  testpar/Makefile
+                 testpar/testpflush.sh
                  tools/Makefile
                  tools/lib/Makefile
                  tools/src/Makefile
diff --git a/examples/CMakeTests.cmake b/examples/CMakeTests.cmake
index dd4766a..6b4504b 100644
--- a/examples/CMakeTests.cmake
+++ b/examples/CMakeTests.cmake
@@ -181,9 +181,9 @@
 ### Windows pops up a modal permission dialog on this test
   if (H5_HAVE_PARALLEL AND NOT WIN32)
     if (HDF5_ENABLE_USING_MEMCHECKER)
-      add_test (NAME EXAMPLES-ph5example COMMAND $<TARGET_FILE:ph5example>)
+      add_test (NAME EXAMPLES_PAR-ph5example COMMAND $<TARGET_FILE:ph5example>)
     else ()
-      add_test (NAME EXAMPLES-ph5example COMMAND "${CMAKE_COMMAND}"
+      add_test (NAME EXAMPLES_PAR-ph5example COMMAND "${CMAKE_COMMAND}"
           -D "TEST_PROGRAM=$<TARGET_FILE:ph5example>"
           -D "TEST_ARGS:STRING="
           -D "TEST_EXPECT=0"
@@ -195,14 +195,14 @@
       )
     endif ()
     if (NOT "${last_test}" STREQUAL "")
-      set_tests_properties (EXAMPLES-ph5example PROPERTIES DEPENDS ${last_test})
+      set_tests_properties (EXAMPLES_PAR-ph5example PROPERTIES DEPENDS ${last_test})
     endif ()
-    set (last_test "EXAMPLES-ph5example")
+    set (last_test "EXAMPLES_PAR-ph5example")
     if (BUILD_SHARED_LIBS)
       if (HDF5_ENABLE_USING_MEMCHECKER)
-        add_test (NAME EXAMPLES-shared-ph5example COMMAND $<TARGET_FILE:ph5example-shared>)
+        add_test (NAME EXAMPLES_PAR-shared-ph5example COMMAND $<TARGET_FILE:ph5example-shared>)
       else ()
-        add_test (NAME EXAMPLES-shared-ph5example COMMAND "${CMAKE_COMMAND}"
+        add_test (NAME EXAMPLES_PAR-shared-ph5example COMMAND "${CMAKE_COMMAND}"
             -D "TEST_PROGRAM=$<TARGET_FILE:ph5example-shared>"
             -D "TEST_ARGS:STRING="
             -D "TEST_EXPECT=0"
@@ -213,10 +213,10 @@
             -P "${HDF_RESOURCES_EXT_DIR}/runTest.cmake"
         )
       endif ()
-      set_tests_properties (EXAMPLES-shared-ph5example PROPERTIES WORKING_DIRECTORY ${PROJECT_BINARY_DIR}/H5EX-shared)
+      set_tests_properties (EXAMPLES_PAR-shared-ph5example PROPERTIES WORKING_DIRECTORY ${PROJECT_BINARY_DIR}/H5EX-shared)
       if (NOT "${last_test}" STREQUAL "")
-        set_tests_properties (EXAMPLES-shared-ph5example PROPERTIES DEPENDS ${last_test})
+        set_tests_properties (EXAMPLES_PAR-shared-ph5example PROPERTIES DEPENDS ${last_test})
       endif ()
-      set (last_test "EXAMPLES-shared-ph5example")
+      set (last_test "EXAMPLES_PAR-shared-ph5example")
     endif ()
   endif ()
diff --git a/java/src/hdf/hdf5lib/H5.java b/java/src/hdf/hdf5lib/H5.java
index bce0034..e354207 100644
--- a/java/src/hdf/hdf5lib/H5.java
+++ b/java/src/hdf/hdf5lib/H5.java
@@ -499,9 +499,9 @@ public class H5 implements java.io.Serializable {
     private synchronized static native boolean H5is_library_threadsafe();
 
     // /////// unimplemented ////////
-    // H5_DLL herr_t H5free_memory(void *mem);
-    // H5_DLL void *H5allocate_memory(size_t size, hbool_t clear);
-    // H5_DLL void *H5resize_memory(void *mem, size_t size);
+    //  herr_t H5free_memory(void *mem);
+    //  void *H5allocate_memory(size_t size, hbool_t clear);
+    //  void *H5resize_memory(void *mem, size_t size);
 
     // ////////////////////////////////////////////////////////////
     // //
@@ -2402,10 +2402,10 @@ public class H5 implements java.io.Serializable {
     public synchronized static native void H5Drefresh(long dset_id) throws HDF5LibraryException;
 
     // /////// unimplemented ////////
-    // H5_DLL herr_t H5Ddebug(hid_t dset_id);
-    // H5_DLL herr_t H5Dget_chunk_storage_size(hid_t dset_id, const hsize_t *offset, hsize_t *chunk_bytes);
-    // H5_DLL herr_t H5Dformat_convert(hid_t dset_id);
-    // H5_DLL herr_t H5Dget_chunk_index_type(hid_t did, H5D_chunk_index_t *idx_type);
+    //  herr_t H5Ddebug(hid_t dset_id);
+    //  herr_t H5Dget_chunk_storage_size(hid_t dset_id, const hsize_t *offset, hsize_t *chunk_bytes);
+    //  herr_t H5Dformat_convert(hid_t dset_id);
+    //  herr_t H5Dget_chunk_index_type(hid_t did, H5D_chunk_index_t *idx_type);
 
     // herr_t H5Dgather(hid_t src_space_id, const void *src_buf, hid_t type_id,
     //                  size_t dst_buf_size, void *dst_buf, H5D_gather_func_t op, void *op_data);
@@ -3230,20 +3230,20 @@ public class H5 implements java.io.Serializable {
             throws HDF5LibraryException, NullPointerException;
 
     // /////// unimplemented ////////
-    // H5_DLL herr_t H5Fget_eoa(hid_t file_id, haddr_t *eoa);
-    // H5_DLL herr_t H5Fincrement_filesize(hid_t file_id, hsize_t increment);
+    //  herr_t H5Fget_eoa(hid_t file_id, haddr_t *eoa);
+    //  herr_t H5Fincrement_filesize(hid_t file_id, hsize_t increment);
     // ssize_t H5Fget_file_image(hid_t file_id, void * buf_ptr, size_t buf_len);
     // herr_t H5Fget_metadata_read_retry_info(hid_t file_id, H5F_retry_info_t *info);
     // ssize_t H5Fget_free_sections(hid_t file_id, H5F_mem_t type, size_t nsects, H5F_sect_info_t *sect_info/*out*/);
-    // H5_DLL herr_t H5Fset_libver_bounds(hid_t file_id, H5F_libver_t low, H5F_libver_t high);
-    // H5_DLL herr_t H5Fformat_convert(hid_t fid);
-    // H5_DLL herr_t H5Freset_page_buffering_stats(hid_t file_id);
-    // H5_DLL herr_t H5Fget_page_buffering_stats(hid_t file_id, unsigned accesses[2],
+    //  herr_t H5Fset_libver_bounds(hid_t file_id, H5F_libver_t low, H5F_libver_t high);
+    //  herr_t H5Fformat_convert(hid_t fid);
+    //  herr_t H5Freset_page_buffering_stats(hid_t file_id);
+    //  herr_t H5Fget_page_buffering_stats(hid_t file_id, unsigned accesses[2],
     //     unsigned hits[2], unsigned misses[2], unsigned evictions[2], unsigned bypasses[2]);
-    // H5_DLL herr_t H5Fget_mdc_image_info(hid_t file_id, haddr_t *image_addr, hsize_t *image_size);
+    //  herr_t H5Fget_mdc_image_info(hid_t file_id, haddr_t *image_addr, hsize_t *image_size);
     // #ifdef H5_HAVE_PARALLEL
-    //   H5_DLL herr_t H5Fset_mpi_atomicity(hid_t file_id, hbool_t flag);
-    //   H5_DLL herr_t H5Fget_mpi_atomicity(hid_t file_id, hbool_t *flag);
+    //    herr_t H5Fset_mpi_atomicity(hid_t file_id, hbool_t flag);
+    //    herr_t H5Fget_mpi_atomicity(hid_t file_id, hbool_t *flag);
     // #endif /* H5_HAVE_PARALLEL */
 
     // /**
@@ -3303,25 +3303,25 @@ public class H5 implements java.io.Serializable {
     // ////////////////////////////////////////////////////////////
 
     // /////// unimplemented ////////
-    // H5_DLL hid_t H5FDregister(const H5FD_class_t *cls);
-    // H5_DLL herr_t H5FDunregister(hid_t driver_id);
-    // H5_DLL H5FD_t *H5FDopen(const char *name, unsigned flags, hid_t fapl_id, haddr_t maxaddr);
-    // H5_DLL herr_t H5FDclose(H5FD_t *file);
-    // H5_DLL int H5FDcmp(const H5FD_t *f1, const H5FD_t *f2);
-    // H5_DLL int H5FDquery(const H5FD_t *f, unsigned long *flags);
-    // H5_DLL haddr_t H5FDalloc(H5FD_t *file, H5FD_mem_t type, hid_t dxpl_id, hsize_t size);
-    // H5_DLL herr_t H5FDfree(H5FD_t *file, H5FD_mem_t type, hid_t dxpl_id, haddr_t addr, hsize_t size);
-    // H5_DLL haddr_t H5FDget_eoa(H5FD_t *file, H5FD_mem_t type);
-    // H5_DLL herr_t H5FDset_eoa(H5FD_t *file, H5FD_mem_t type, haddr_t eoa);
-    // H5_DLL haddr_t H5FDget_eof(H5FD_t *file, H5FD_mem_t type);
-    // H5_DLL herr_t H5FDget_vfd_handle(H5FD_t *file, hid_t fapl, void**file_handle);
-    // H5_DLL herr_t H5FDread(H5FD_t *file, H5FD_mem_t type, hid_t dxpl_id, haddr_t addr, size_t size, void *buf/*out*/);
-    // H5_DLL herr_t H5FDwrite(H5FD_t *file, H5FD_mem_t type, hid_t dxpl_id, haddr_t addr, size_t size, const void *buf);
-    // H5_DLL herr_t H5FDflush(H5FD_t *file, hid_t dxpl_id, hbool_t closing);
-    // H5_DLL herr_t H5FDtruncate(H5FD_t *file, hid_t dxpl_id, hbool_t closing);
-    // H5_DLL herr_t H5FDlock(H5FD_t *file, hbool_t rw);
-    // H5_DLL herr_t H5FDunlock(H5FD_t *file);
-    // H5_DLL herr_t H5FDdriver_query(hid_t driver_id, unsigned long *flags/*out*/);
+    //  hid_t H5FDregister(const H5FD_class_t *cls);
+    //  herr_t H5FDunregister(hid_t driver_id);
+    //  H5FD_t *H5FDopen(const char *name, unsigned flags, hid_t fapl_id, haddr_t maxaddr);
+    //  herr_t H5FDclose(H5FD_t *file);
+    //  int H5FDcmp(const H5FD_t *f1, const H5FD_t *f2);
+    //  int H5FDquery(const H5FD_t *f, unsigned long *flags);
+    //  haddr_t H5FDalloc(H5FD_t *file, H5FD_mem_t type, hid_t dxpl_id, hsize_t size);
+    //  herr_t H5FDfree(H5FD_t *file, H5FD_mem_t type, hid_t dxpl_id, haddr_t addr, hsize_t size);
+    //  haddr_t H5FDget_eoa(H5FD_t *file, H5FD_mem_t type);
+    //  herr_t H5FDset_eoa(H5FD_t *file, H5FD_mem_t type, haddr_t eoa);
+    //  haddr_t H5FDget_eof(H5FD_t *file, H5FD_mem_t type);
+    //  herr_t H5FDget_vfd_handle(H5FD_t *file, hid_t fapl, void**file_handle);
+    //  herr_t H5FDread(H5FD_t *file, H5FD_mem_t type, hid_t dxpl_id, haddr_t addr, size_t size, void *buf/*out*/);
+    //  herr_t H5FDwrite(H5FD_t *file, H5FD_mem_t type, hid_t dxpl_id, haddr_t addr, size_t size, const void *buf);
+    //  herr_t H5FDflush(H5FD_t *file, hid_t dxpl_id, hbool_t closing);
+    //  herr_t H5FDtruncate(H5FD_t *file, hid_t dxpl_id, hbool_t closing);
+    //  herr_t H5FDlock(H5FD_t *file, hbool_t rw);
+    //  herr_t H5FDunlock(H5FD_t *file);
+    //  herr_t H5FDdriver_query(hid_t driver_id, unsigned long *flags/*out*/);
 
     // ////////////////////////////////////////////////////////////
     // //
@@ -3794,7 +3794,7 @@ public class H5 implements java.io.Serializable {
 
     // ////////////////////////////////////////////////////////////
     // //
-    // H5I: HDF5 1.8 Identifier Interface API Functions //
+    // H5I: HDF5 Identifier Interface API Functions //
     // //
     // ////////////////////////////////////////////////////////////
 
@@ -3950,12 +3950,20 @@ public class H5 implements java.io.Serializable {
 
     // hid_t H5Iregister(H5I_type_t type, const void *object);
 
+    // typedef herr_t (*H5I_free_t)(void *);
     // H5I_type_t H5Iregister_type(size_t hash_size, unsigned reserved, H5I_free_t free_func);
 
     // void *H5Iremove_verify(hid_t id, H5I_type_t id_type);
 
+    // Type of the function to compare objects & keys
+    // typedef int (*H5I_search_func_t)(void *obj, hid_t id, void *key);
     // void *H5Isearch(H5I_type_t type, H5I_search_func_t func, void *key);
 
+    // Type of the H5Iiterate callback function
+    // typedef herr_t (*H5I_iterate_func_t)(hid_t id, void *udata);
+    // herr_t H5Iiterate(H5I_type_t type, H5I_iterate_func_t op, void *op_data);
+
+
     // //////////////////////////////////////////////////////////////////
     // H5L: Link Interface Functions //
     // //////////////////////////////////////////////////////////////////
@@ -4983,9 +4991,9 @@ public class H5 implements java.io.Serializable {
     public synchronized static native void H5Orefresh(long object_id) throws HDF5LibraryException;
 
     // /////// unimplemented ////////
-    // H5_DLL herr_t H5Odisable_mdc_flushes(hid_t object_id);
-    // H5_DLL herr_t H5Oenable_mdc_flushes(hid_t object_id);
-    // H5_DLL herr_t H5Oare_mdc_flushes_disabled(hid_t object_id, hbool_t *are_disabled);
+    //  herr_t H5Odisable_mdc_flushes(hid_t object_id);
+    //  herr_t H5Oenable_mdc_flushes(hid_t object_id);
+    //  herr_t H5Oare_mdc_flushes_disabled(hid_t object_id, hbool_t *are_disabled);
 
     // ////////////////////////////////////////////////////////////
     // //
@@ -5270,6 +5278,27 @@ public class H5 implements java.io.Serializable {
 
     private synchronized static native long _H5Pcopy(long plist) throws HDF5LibraryException;
 
+    // Define property list class callback function pointer types
+    // typedef herr_t (*H5P_cls_create_func_t)(hid_t prop_id, void *create_data);
+    // typedef herr_t (*H5P_cls_copy_func_t)(hid_t new_prop_id, hid_t old_prop_id, void *copy_data);
+    // typedef herr_t (*H5P_cls_close_func_t)(hid_t prop_id, void *close_data);
+
+    // Define property list callback function pointer types
+    // typedef herr_t (*H5P_prp_cb1_t)(const char *name, size_t size, void *value);
+    // typedef herr_t (*H5P_prp_cb2_t)(hid_t prop_id, const char *name, size_t size, void *value);
+    // typedef H5P_prp_cb1_t H5P_prp_create_func_t;
+    // typedef H5P_prp_cb2_t H5P_prp_set_func_t;
+    // typedef H5P_prp_cb2_t H5P_prp_get_func_t;
+    // typedef herr_t (*H5P_prp_encode_func_t)(const void *value, void **buf, size_t *size);
+    // typedef herr_t (*H5P_prp_decode_func_t)(const void **buf, void *value);
+    // typedef H5P_prp_cb2_t H5P_prp_delete_func_t;
+    // typedef H5P_prp_cb1_t H5P_prp_copy_func_t;
+    // typedef int (*H5P_prp_compare_func_t)(const void *value1, const void *value2, size_t size);
+    // typedef H5P_prp_cb1_t H5P_prp_close_func_t;
+
+    // Define property list iteration function type
+    // typedef herr_t (*H5P_iterate_t)(hid_t id, const char *name, void *iter_data);
+
     public static long H5Pcreate_class_nocb(long parent_class, String name) throws HDF5LibraryException {
         long id = _H5Pcreate_class_nocb(parent_class, name);
           if (id > 0) {
@@ -6433,6 +6462,11 @@ public class H5 implements java.io.Serializable {
     public synchronized static native void H5Pset_evict_on_close(long fapl_id, boolean evict_on_close)
             throws HDF5LibraryException;
 
+    //  /////  unimplemented /////
+    // herr_t H5Pset_vol(hid_t plist_id, hid_t new_vol_id, const void *new_vol_info);
+    // herr_t H5Pget_vol_id(hid_t plist_id, hid_t *vol_id);
+    // herr_t H5Pget_vol_info(hid_t plist_id, void **vol_info);
+
     // Dataset creation property list (DCPL) routines //
 
     /**
@@ -7811,13 +7845,13 @@ public class H5 implements java.io.Serializable {
     // herr_t H5Pget_core_write_tracking(hid_t fapl_id, hbool_t *is_enabled, size_t *page_size);
     // #ifdef H5_HAVE_PARALLEL
     // herr_t H5Pset_all_coll_metadata_ops(hid_t accpl_id, hbool_t is_collective);
-    // H5_DLL herr_t H5Pget_all_coll_metadata_ops(hid_t plist_id, hbool_t *is_collective);
+    //  herr_t H5Pget_all_coll_metadata_ops(hid_t plist_id, hbool_t *is_collective);
     // herr_t H5Pset_coll_metadata_write(hid_t fapl_id, hbool_t is_collective);
     // herr_t H5Pget_coll_metadata_write(hid_t fapl_id, hbool_t *is_collective);
     // #endif /* H5_HAVE_PARALLEL */
-    // H5_DLL herr_t H5Pset_mdc_image_config(hid_t plist_id, H5AC_cache_image_config_t *config_ptr);
-    // H5_DLL herr_t H5Pget_mdc_image_config(hid_t plist_id, H5AC_cache_image_config_t *config_ptr /*out*/);
-    // H5_DLL herr_t H5Pset_page_buffer_size(hid_t plist_id, size_t buf_size, unsigned min_meta_per, unsigned min_raw_per);
+    //  herr_t H5Pset_mdc_image_config(hid_t plist_id, H5AC_cache_image_config_t *config_ptr);
+    //  herr_t H5Pget_mdc_image_config(hid_t plist_id, H5AC_cache_image_config_t *config_ptr /*out*/);
+    //  herr_t H5Pset_page_buffer_size(hid_t plist_id, size_t buf_size, unsigned min_meta_per, unsigned min_raw_per);
     // herr_t H5Pget_page_buffer_size(hid_t fapl_id, size_t *buf_size, unsigned *min_meta_perc, unsigned *min_raw_perc);
     // herr_t H5Pset_object_flush_cb (hid_t fapl_id, H5F_flush_cb_t func, void *user_data);
     // herr_t H5Pget_object_flush_cb (hid_t fapl_id, H5F_flush_cb_t *func, void **user_data);
@@ -7840,9 +7874,9 @@ public class H5 implements java.io.Serializable {
     // herr_t H5Pget_type_conv_cb(hid_t plist, H5T_conv_except_func_t *func, void **op_data)
     // herr_t H5Pset_type_conv_cb( hid_t plist, H5T_conv_except_func_t func, void *op_data)
     // #ifdef H5_HAVE_PARALLEL
-    // H5_DLL herr_t H5Pget_mpio_actual_chunk_opt_mode(hid_t plist_id, H5D_mpio_actual_chunk_opt_mode_t *actual_chunk_opt_mode);
-    // H5_DLL herr_t H5Pget_mpio_actual_io_mode(hid_t plist_id, H5D_mpio_actual_io_mode_t *actual_io_mode);
-    // H5_DLL herr_t H5Pget_mpio_no_collective_cause(hid_t plist_id, uint32_t *local_no_collective_cause, uint32_t *global_no_collective_cause);
+    //  herr_t H5Pget_mpio_actual_chunk_opt_mode(hid_t plist_id, H5D_mpio_actual_chunk_opt_mode_t *actual_chunk_opt_mode);
+    //  herr_t H5Pget_mpio_actual_io_mode(hid_t plist_id, H5D_mpio_actual_io_mode_t *actual_io_mode);
+    //  herr_t H5Pget_mpio_no_collective_cause(hid_t plist_id, uint32_t *local_no_collective_cause, uint32_t *global_no_collective_cause);
     // #endif /* H5_HAVE_PARALLEL */
 
     // Link creation property list (LCPL) routines //
@@ -8785,16 +8819,17 @@ public class H5 implements java.io.Serializable {
 
     // /////// unimplemented ////////
     // #ifdef NEW_HYPERSLAB_API
-    // H5_DLL hid_t H5Scombine_hyperslab(hid_t space_id, H5S_seloper_t op,
+    //  hid_t H5Scombine_hyperslab(hid_t space_id, H5S_seloper_t op,
     //                                  const hsize_t start[],
     //                                  const hsize_t _stride[],
     //                                  const hsize_t count[],
     //                                  const hsize_t _block[]);
-    // H5_DLL herr_t H5Sselect_select(hid_t space1_id, H5S_seloper_t op,
+    // herr_t H5Sselect_select(hid_t space1_id, H5S_seloper_t op,
     //                                  hid_t space2_id);
-    // H5_DLL hid_t H5Scombine_select(hid_t space1_id, H5S_seloper_t op,
+    // hid_t H5Scombine_select(hid_t space1_id, H5S_seloper_t op,
     //                                  hid_t space2_id);
     // #endif /* NEW_HYPERSLAB_API */
+    // herr_t H5Sselect_copy(hid_t dst_id, hid_t src_id);
 
 
 
@@ -10273,6 +10308,25 @@ public class H5 implements java.io.Serializable {
 
     // ////////////////////////////////////////////////////////////
     // //
+    // H5VL: VOL Interface Functions //
+    // //
+    // ////////////////////////////////////////////////////////////
+
+    /// VOL Connector Functionality
+    public synchronized static native long H5VLregister_connector_by_name(String connector_name, long vipl_id);
+    public synchronized static native long H5VLregister_connector_by_value(int connector_value, long vipl_id);
+    public synchronized static native boolean H5VLis_connector_registered(String name);
+    public synchronized static native long H5VLget_connector_id(String name);
+    public synchronized static native String H5VLget_connector_name(long object_id);
+    public synchronized static native void H5VLclose(long connector_id);
+    public synchronized static native void H5VLunregister_connector(long connector_id);
+
+    // /////// unimplemented ////////
+    // hid_t H5VLregister_connector(const H5VL_class_t *cls, hid_t vipl_id);
+
+
+    // ////////////////////////////////////////////////////////////
+    // //
     // H5Z: Filter Interface Functions //
     // //
     // ////////////////////////////////////////////////////////////
@@ -10283,9 +10337,9 @@ public class H5 implements java.io.Serializable {
 
     public synchronized static native int H5Zunregister(int filter) throws HDF5LibraryException, NullPointerException;
 
-}
+    // /////// unimplemented ////////
 
-// /////// unimplemented ////////
+    // herr_t H5Zregister(const void *cls);
 
-// herr_t H5Zregister(const void *cls);
+}
 
diff --git a/java/src/hdf/hdf5lib/HDF5Constants.java b/java/src/hdf/hdf5lib/HDF5Constants.java
index 0760e7f..a0c2ed6 100644
--- a/java/src/hdf/hdf5lib/HDF5Constants.java
+++ b/java/src/hdf/hdf5lib/HDF5Constants.java
@@ -195,6 +195,11 @@ public class HDF5Constants {
     public static final long H5E_WALK_UPWARD = H5E_WALK_UPWARD();
     public static final long H5E_WRITEERROR = H5E_WRITEERROR();
 
+    private static final int H5ES_STATUS_IN_PROGRESS = H5ES_STATUS_IN_PROGRESS();
+    private static final int H5ES_STATUS_SUCCEED = H5ES_STATUS_SUCCEED();
+    private static final int H5ES_STATUS_FAIL = H5ES_STATUS_FAIL();
+    private static final int H5ES_STATUS_CANCELED = H5ES_STATUS_CANCELED();
+
     public static final int H5F_ACC_CREAT = H5F_ACC_CREAT();
     public static final int H5F_ACC_EXCL = H5F_ACC_EXCL();
     public static final int H5F_ACC_RDONLY = H5F_ACC_RDONLY();
@@ -389,7 +394,10 @@ public class HDF5Constants {
 
     public static final int H5PL_TYPE_ERROR = H5PL_TYPE_ERROR();
     public static final int H5PL_TYPE_FILTER = H5PL_TYPE_FILTER();
+    public static final int H5PL_TYPE_VOL = H5PL_TYPE_VOL();
+    public static final int H5PL_TYPE_NONE = H5PL_TYPE_NONE();
     public static final int H5PL_FILTER_PLUGIN = H5PL_FILTER_PLUGIN();
+    public static final int H5PL_VOL_PLUGIN = H5PL_VOL_PLUGIN();
     public static final int H5PL_ALL_PLUGIN = H5PL_ALL_PLUGIN();
 
     public static final int H5R_BADTYPE = H5R_BADTYPE();
@@ -625,6 +633,18 @@ public class HDF5Constants {
     public static final long H5T_VARIABLE = H5T_VARIABLE();
     public static final int H5T_VLEN = H5T_VLEN();
     public static final int H5T_VL_T = H5T_VL_T();
+
+    public static final int H5VL_CAP_FLAG_NONE = H5VL_CAP_FLAG_NONE();
+    public static final int H5VL_CAP_FLAG_THREADSAFE = H5VL_CAP_FLAG_THREADSAFE();
+    public static final long H5VL_NATIVE = H5VL_NATIVE();
+    public static final String H5VL_NATIVE_NAME = H5VL_NATIVE_NAME();
+    public static final int H5VL_NATIVE_VALUE = H5VL_NATIVE_VALUE();
+    public static final int H5VL_NATIVE_VERSION = H5VL_NATIVE_VERSION();
+    public static final int H5_VOL_INVALID = H5_VOL_INVALID();
+    public static final int H5_VOL_NATIVE = H5_VOL_NATIVE();
+    public static final int H5_VOL_RESERVED = H5_VOL_RESERVED();
+    public static final int H5_VOL_MAX = H5_VOL_MAX();
+
     public static final int H5Z_CB_CONT = H5Z_CB_CONT();
     public static final int H5Z_CB_ERROR = H5Z_CB_ERROR();
     public static final int H5Z_CB_FAIL = H5Z_CB_FAIL();
@@ -989,6 +1009,14 @@ public class HDF5Constants {
 
     private static native final long H5E_WRITEERROR();
 
+    private static native final int H5ES_STATUS_IN_PROGRESS();
+
+    private static native final int H5ES_STATUS_SUCCEED();
+
+    private static native final int H5ES_STATUS_FAIL();
+
+    private static native final int H5ES_STATUS_CANCELED();
+
     private static native final int H5F_ACC_CREAT();
 
     private static native final int H5F_ACC_EXCL();
@@ -1361,10 +1389,16 @@ public class HDF5Constants {
 
     private static native final int H5PL_TYPE_FILTER();
 
+    private static native final int H5PL_TYPE_VOL();
+
+    private static native final int H5PL_TYPE_NONE();
+
     private static native final int H5PL_FILTER_PLUGIN();
 
     private static native final int H5PL_ALL_PLUGIN();
 
+    private static native final int H5PL_VOL_PLUGIN();
+
     private static native final int H5R_BADTYPE();
 
     private static native final int H5R_DATASET_REGION();
@@ -1831,6 +1865,26 @@ public class HDF5Constants {
 
     private static native final int H5T_VL_T();
 
+    private static native final int H5VL_CAP_FLAG_NONE();
+
+    private static native final int H5VL_CAP_FLAG_THREADSAFE();
+
+    private static native final long H5VL_NATIVE();
+
+    private static native final String H5VL_NATIVE_NAME();
+
+    private static native final int H5VL_NATIVE_VALUE();
+
+    private static native final int H5VL_NATIVE_VERSION();
+
+    private static native final int H5_VOL_INVALID();
+
+    private static native final int H5_VOL_NATIVE();
+
+    private static native final int H5_VOL_RESERVED();
+
+    private static native final int H5_VOL_MAX();
+
     private static native final int H5Z_CB_CONT();
 
     private static native final int H5Z_CB_ERROR();
diff --git a/java/src/jni/CMakeLists.txt b/java/src/jni/CMakeLists.txt
index 50e76e1..00c2b34 100644
--- a/java/src/jni/CMakeLists.txt
+++ b/java/src/jni/CMakeLists.txt
@@ -19,6 +19,7 @@ set (HDF5_JAVA_JNI_CSRCS
     ${HDF5_JAVA_JNI_SOURCE_DIR}/h5sImp.c
     ${HDF5_JAVA_JNI_SOURCE_DIR}/h5tImp.c
     ${HDF5_JAVA_JNI_SOURCE_DIR}/h5util.c
+    ${HDF5_JAVA_JNI_SOURCE_DIR}/h5vlImp.c
     ${HDF5_JAVA_JNI_SOURCE_DIR}/h5zImp.c
     ${HDF5_JAVA_JNI_SOURCE_DIR}/nativeData.c
 )
@@ -40,6 +41,7 @@ set (HDF5_JAVA_JNI_CHDRS
     ${HDF5_JAVA_JNI_SOURCE_DIR}/h5sImp.h
     ${HDF5_JAVA_JNI_SOURCE_DIR}/h5tImp.h
     ${HDF5_JAVA_JNI_SOURCE_DIR}/h5util.h
+    ${HDF5_JAVA_JNI_SOURCE_DIR}/h5vlImp.h
     ${HDF5_JAVA_JNI_SOURCE_DIR}/h5zImp.h
     ${HDF5_JAVA_JNI_SOURCE_DIR}/nativeData.h
 )
diff --git a/java/src/jni/Makefile.am b/java/src/jni/Makefile.am
index 6ded371..370b08b 100644
--- a/java/src/jni/Makefile.am
+++ b/java/src/jni/Makefile.am
@@ -34,7 +34,7 @@ libhdf5_java_la_LDFLAGS = -avoid-version -shared -export-dynamic -version-info $
 # Source files for the library
 libhdf5_java_la_SOURCES=exceptionImp.c h5Constants.c nativeData.c h5util.c h5Imp.c \
 	h5aImp.c h5dImp.c h5eImp.c h5fImp.c h5gImp.c h5iImp.c h5lImp.c h5oImp.c    \
-	h5pImp.c h5plImp.c h5rImp.c h5sImp.c h5tImp.c h5zImp.c
+	h5pImp.c h5plImp.c h5rImp.c h5sImp.c h5tImp.c h5vlImp.c h5zImp.c
 
 # HDF5 Java (JNI) library depends on HDF5 Library.
 libhdf5_java_la_LIBADD=$(LIBHDF5)
diff --git a/java/src/jni/h5Constants.c b/java/src/jni/h5Constants.c
index b13dc76..e88fa55 100644
--- a/java/src/jni/h5Constants.c
+++ b/java/src/jni/h5Constants.c
@@ -21,8 +21,10 @@
 extern "C" {
 #endif /* __cplusplus */
 
-#include <jni.h>
 #include "hdf5.h"
+#include <jni.h>
+#include <stdlib.h>
+#include "h5jni.h"
 
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wmissing-prototypes"
@@ -352,6 +354,15 @@ Java_hdf_hdf5lib_HDF5Constants_H5E_1WALK_1UPWARD(JNIEnv *env, jclass cls) { retu
 JNIEXPORT jlong JNICALL
 Java_hdf_hdf5lib_HDF5Constants_H5E_1WRITEERROR(JNIEnv *env, jclass cls) { return H5E_WRITEERROR; }
 
+JNIEXPORT jlong JNICALL
+Java_hdf_hdf5lib_HDF5Constants_H5ES_1STATUS_1IN_1PROGRESS(JNIEnv *env, jclass cls) { return H5ES_STATUS_IN_PROGRESS; }
+JNIEXPORT jlong JNICALL
+Java_hdf_hdf5lib_HDF5Constants_H5ES_1STATUS_1SUCCEED(JNIEnv *env, jclass cls) { return H5ES_STATUS_SUCCEED; }
+JNIEXPORT jlong JNICALL
+Java_hdf_hdf5lib_HDF5Constants_H5ES_1STATUS_1FAIL(JNIEnv *env, jclass cls) { return H5ES_STATUS_FAIL; }
+JNIEXPORT jlong JNICALL
+Java_hdf_hdf5lib_HDF5Constants_H5ES_1STATUS_1CANCELED(JNIEnv *env, jclass cls) { return H5ES_STATUS_CANCELED; }
+
 /* Java does not have unsigned native types */
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wsign-conversion"
@@ -761,8 +772,14 @@ Java_hdf_hdf5lib_HDF5Constants_H5PL_1TYPE_1ERROR(JNIEnv *env, jclass cls) { retu
 JNIEXPORT jint JNICALL
 Java_hdf_hdf5lib_HDF5Constants_H5PL_1TYPE_1FILTER(JNIEnv *env, jclass cls) { return H5PL_TYPE_FILTER; }
 JNIEXPORT jint JNICALL
+Java_hdf_hdf5lib_HDF5Constants_H5PL_1TYPE_1VOL(JNIEnv *env, jclass cls) { return H5PL_TYPE_VOL; }
+JNIEXPORT jint JNICALL
+Java_hdf_hdf5lib_HDF5Constants_H5PL_1TYPE_1NONE(JNIEnv *env, jclass cls) { return H5PL_TYPE_NONE; }
+JNIEXPORT jint JNICALL
 Java_hdf_hdf5lib_HDF5Constants_H5PL_1FILTER_1PLUGIN(JNIEnv *env, jclass cls) { return H5PL_FILTER_PLUGIN; }
 JNIEXPORT jint JNICALL
+Java_hdf_hdf5lib_HDF5Constants_H5PL_1VOL_1PLUGIN(JNIEnv *env, jclass cls) { return H5PL_VOL_PLUGIN; }
+JNIEXPORT jint JNICALL
 Java_hdf_hdf5lib_HDF5Constants_H5PL_1ALL_1PLUGIN(JNIEnv *env, jclass cls) { return H5PL_ALL_PLUGIN; }
 
 JNIEXPORT jint JNICALL
@@ -1237,6 +1254,28 @@ JNIEXPORT jint JNICALL
 Java_hdf_hdf5lib_HDF5Constants_H5T_1VL_1T(JNIEnv *env, jclass cls) { return sizeof(hvl_t); }
 
 JNIEXPORT jint JNICALL
+Java_hdf_hdf5lib_HDF5Constants_H5VL_1CAP_1FLAG_1NONE(JNIEnv *env, jclass cls) { return H5VL_CAP_FLAG_NONE; }
+JNIEXPORT jint JNICALL
+Java_hdf_hdf5lib_HDF5Constants_H5VL_1CAP_1FLAG_1THREADSAFE(JNIEnv *env, jclass cls) { return H5VL_CAP_FLAG_THREADSAFE; }
+JNIEXPORT jlong JNICALL
+Java_hdf_hdf5lib_HDF5Constants_H5VL_1NATIVE(JNIEnv *env, jclass cls) { return H5VL_NATIVE; }
+JNIEXPORT jobject JNICALL
+Java_hdf_hdf5lib_HDF5Constants_H5VL_1NATIVE_1NAME(JNIEnv *env, jclass cls) { return (jstring)ENVPTR->NewStringUTF(ENVPAR H5VL_NATIVE_NAME); }
+JNIEXPORT jint JNICALL
+Java_hdf_hdf5lib_HDF5Constants_H5VL_1NATIVE_1VALUE(JNIEnv *env, jclass cls) { return H5VL_NATIVE_VALUE; }
+JNIEXPORT jint JNICALL
+Java_hdf_hdf5lib_HDF5Constants_H5VL_1NATIVE_1VERSION(JNIEnv *env, jclass cls) { return H5VL_NATIVE_VERSION; }
+
+JNIEXPORT jint JNICALL
+Java_hdf_hdf5lib_HDF5Constants_H5_1VOL_1INVALID(JNIEnv *env, jclass cls) { return H5_VOL_INVALID; }
+JNIEXPORT jint JNICALL
+Java_hdf_hdf5lib_HDF5Constants_H5_1VOL_1NATIVE(JNIEnv *env, jclass cls) { return H5_VOL_NATIVE; }
+JNIEXPORT jint JNICALL
+Java_hdf_hdf5lib_HDF5Constants_H5_1VOL_1RESERVED(JNIEnv *env, jclass cls) { return H5_VOL_RESERVED; }
+JNIEXPORT jint JNICALL
+Java_hdf_hdf5lib_HDF5Constants_H5_1VOL_1MAX(JNIEnv *env, jclass cls) { return H5_VOL_MAX; }
+
+JNIEXPORT jint JNICALL
 Java_hdf_hdf5lib_HDF5Constants_H5Z_1CB_1CONT(JNIEnv *env, jclass cls) { return H5Z_CB_CONT; }
 JNIEXPORT jint JNICALL
 Java_hdf_hdf5lib_HDF5Constants_H5Z_1CB_1ERROR(JNIEnv *env, jclass cls) { return H5Z_CB_ERROR; }
diff --git a/java/src/jni/h5vlImp.c b/java/src/jni/h5vlImp.c
new file mode 100644
index 0000000..89ea703
--- /dev/null
+++ b/java/src/jni/h5vlImp.c
@@ -0,0 +1,206 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*
+ *  For details of the HDF libraries, see the HDF Documentation at:
+ *    http://hdfgroup.org/HDF5/doc/
+ *
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+#include "hdf5.h"
+#include <jni.h>
+#include <stdlib.h>
+#include "h5jni.h"
+#include "h5vlImp.h"
+
+/*
+ * Class:     hdf_hdf5lib_H5
+ * Method:    H5VLregister_connector_by_name
+ * Signature: (Ljava/lang/String;J)J
+ */
+JNIEXPORT jlong JNICALL
+Java_hdf_hdf5lib_H5_H5VLregister_1connector_1by_1name
+  (JNIEnv *env, jclass clss, jobject connector_name, jlong vipl_id)
+{
+    hid_t       status = -1;
+    const char *vlName;
+
+    PIN_JAVA_STRING(connector_name, vlName);
+    if (vlName != NULL) {
+        status = H5VLregister_connector_by_name(vlName, (hid_t)vipl_id);
+
+        UNPIN_JAVA_STRING(connector_name, vlName);
+
+        if (status < 0)
+            h5libraryError(env);
+    }
+
+    return (jlong)status;
+} /* end Java_hdf_hdf5lib_H5_H5VLregister_1connector_1by_1name */
+
+/*
+ * Class:     hdf_hdf5lib_H5
+ * Method:    H5VLregister_connector_by_value
+ * Signature: (IJ)J
+ */
+JNIEXPORT jlong JNICALL
+Java_hdf_hdf5lib_H5_H5VLregister_1connector_1by_1value
+  (JNIEnv *env, jclass clss, jint connector_value, jlong vipl_id)
+{
+    hid_t status = H5VLregister_connector_by_value((H5VL_class_value_t)connector_value, (hid_t)vipl_id);
+
+    if (status < 0)
+        h5libraryError(env);
+
+    return (jlong)status;
+} /* end Java_hdf_hdf5lib_H5_H5VLregister_1connector_1by_1value */
+
+/*
+ * Class:     hdf_hdf5lib_H5
+ * Method:    H5VLis_connector_registered
+ * Signature: (Ljava/lang/String;)Z
+ */
+JNIEXPORT jboolean JNICALL
+Java_hdf_hdf5lib_H5_H5VLis_1connector_1registered
+  (JNIEnv *env, jclass clss, jobject connector_name)
+{
+    htri_t      bval = JNI_FALSE;
+    const char *vlName;
+
+    PIN_JAVA_STRING(connector_name, vlName);
+    if (vlName != NULL) {
+        bval = H5VLis_connector_registered(vlName);
+
+        UNPIN_JAVA_STRING(connector_name, vlName);
+
+        if (bval > 0)
+            bval = JNI_TRUE;
+        else if (bval < 0)
+            h5libraryError(env);
+    }
+
+    return (jboolean)bval;
+} /* end Java_hdf_hdf5lib_H5_H5VLis_1connector_1registered */
+
+/*
+ * Class:     hdf_hdf5lib_H5
+ * Method:    H5VLget_connector_id
+ * Signature: (Ljava/lang/String;)J
+ */
+JNIEXPORT jlong JNICALL
+Java_hdf_hdf5lib_H5_H5VLget_1connector_1id
+  (JNIEnv *env, jclass clss, jobject connector_name)
+{
+    hid_t       status = -1;
+    const char *vlName;
+
+    PIN_JAVA_STRING(connector_name, vlName);
+    if (vlName != NULL) {
+        status = H5VLget_connector_id(vlName);
+
+        UNPIN_JAVA_STRING(connector_name, vlName);
+
+        if (status < 0)
+            h5libraryError(env);
+    }
+
+    return (jlong)status;
+} /* end Java_hdf_hdf5lib_H5_H5VLget_1connector_1id */
+
+/*
+ * Class:     hdf_hdf5lib_H5
+ * Method:    H5VLget_connector_name
+ * Signature: (J)Ljava/lang/String;
+ */
+
+JNIEXPORT jobject JNICALL
+Java_hdf_hdf5lib_H5_H5VLget_1connector_1name
+  (JNIEnv *env, jclass clss, jlong object_id)
+{
+    char    *vlName;
+    ssize_t  buf_size;
+    ssize_t  status;
+    jstring  str = NULL;
+
+    /* get the length of the comment */
+    buf_size = H5VLget_connector_name((hid_t)object_id, NULL, 0);
+    if (buf_size < 0) {
+        H5Eprint2(H5E_DEFAULT, NULL);
+
+        h5badArgument(env, "H5VLget_connector_name:  buf_size < 0");
+    } /* end if */
+    else if (buf_size > 0) {
+        buf_size++; /* add extra space for the null terminator */
+        vlName = (char *)HDmalloc(sizeof(char) * (size_t)buf_size);
+        if (vlName == NULL) {
+            /* exception -- out of memory */
+            h5outOfMemory(env, "H5VLget_connector_name:  malloc failed");
+        } /* end if */
+        else {
+            status = H5VLget_connector_name((hid_t)object_id, vlName, (size_t)buf_size);
+
+            if (status < 0) {
+                h5libraryError(env);
+            } /* end if */
+            else {
+                /*  may throw OutOfMemoryError */
+                str = ENVPTR->NewStringUTF(ENVPAR vlName);
+                if (str == NULL) {
+                    h5JNIFatalError(env, "H5VLget_connector_name:  return string not allocated");
+                } /* end if */
+            } /* end else */
+            HDfree(vlName);
+        }
+    } /* end else if */
+
+    return (jstring)str;
+} /* end Java_hdf_hdf5lib_H5_H5VLget_1connector_1name */
+
+/*
+ * Class:     hdf_hdf5lib_H5
+ * Method:    H5VLclose
+ * Signature: (J)V
+ */
+JNIEXPORT void JNICALL
+Java_hdf_hdf5lib_H5_H5VLclose
+  (JNIEnv *env, jclass clss, jlong connector_id)
+{
+    herr_t retValue = H5VLclose((hid_t)connector_id);
+
+    if (retValue < 0)
+        h5libraryError(env);
+} /* end Java_hdf_hdf5lib_H5_H5VLclose */
+
+/*
+ * Class:     hdf_hdf5lib_H5
+ * Method:    H5VLunregister_connector
+ * Signature: (J)V
+ */
+JNIEXPORT void JNICALL
+Java_hdf_hdf5lib_H5_H5VLunregister_1connector
+    (JNIEnv *env, jclass clss, jlong connector_id)
+{
+    herr_t retValue = H5VLunregister_connector((hid_t)connector_id);
+
+    if (retValue < 0)
+        h5libraryError(env);
+} /* end Java_hdf_hdf5lib_H5_H5VLunregister_1connector */
+
+
+#ifdef __cplusplus
+} /* end extern "C" */
+#endif /* __cplusplus */
diff --git a/java/src/jni/h5vlImp.h b/java/src/jni/h5vlImp.h
new file mode 100644
index 0000000..af824a9
--- /dev/null
+++ b/java/src/jni/h5vlImp.h
@@ -0,0 +1,91 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#include <jni.h>
+/* Header for class hdf_hdf5lib_H5_H5VL */
+
+#ifndef _Included_hdf_hdf5lib_H5_H5VL
+#define _Included_hdf_hdf5lib_H5_H5VL
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+/*
+ * Class:     hdf_hdf5lib_H5
+ * Method:    H5VLregister_connector_by_name
+ * Signature: (Ljava/lang/String;J)J
+ */
+JNIEXPORT jlong JNICALL
+Java_hdf_hdf5lib_H5_H5VLregister_1connector_1by_1name
+  (JNIEnv *, jclass, jobject, jlong);
+
+/*
+ * Class:     hdf_hdf5lib_H5
+ * Method:    H5VLregister_connector_by_value
+ * Signature: (IJ)J
+ */
+JNIEXPORT jlong JNICALL
+Java_hdf_hdf5lib_H5_H5VLregister_1connector_1by_1value
+  (JNIEnv *, jclass, jint, jlong);
+
+/*
+ * Class:     hdf_hdf5lib_H5
+ * Method:    H5VLis_connector_registered
+ * Signature: (Ljava/lang/String;)Z
+ */
+JNIEXPORT jboolean JNICALL
+Java_hdf_hdf5lib_H5_H5VLis_connector_registered
+  (JNIEnv *, jclass, jobject);
+
+/*
+ * Class:     hdf_hdf5lib_H5
+ * Method:    H5VLget_connector_id
+ * Signature: (Ljava/lang/String;)J
+ */
+JNIEXPORT jlong JNICALL
+Java_hdf_hdf5lib_H5_H5VLget_1connector_1id
+  (JNIEnv *, jclass, jobject);
+
+/*
+ * Class:     hdf_hdf5lib_H5
+ * Method:    H5VLget_connector_name
+ * Signature: (J)Ljava/lang/String;
+ */
+
+JNIEXPORT jobject JNICALL
+Java_hdf_hdf5lib_H5_H5VLget_1connector_1name
+  (JNIEnv *, jclass, jlong);
+
+/*
+ * Class:     hdf_hdf5lib_H5
+ * Method:    H5VLclose
+ * Signature: (J)V
+ */
+JNIEXPORT void JNICALL
+Java_hdf_hdf5lib_H5_H5VLclose
+  (JNIEnv *, jclass, jlong);
+
+/*
+ * Class:     hdf_hdf5lib_H5
+ * Method:    H5VLunregister_connector
+ * Signature: (J)V
+ */
+JNIEXPORT void JNICALL
+Java_hdf_hdf5lib_H5_H5VLunregister_1connector
+  (JNIEnv *, jclass, jlong);
+
+#ifdef __cplusplus
+} /* end extern "C" */
+#endif /* __cplusplus */
+
+#endif /* _Included_hdf_hdf5lib_H5_H5VL */
diff --git a/java/test/CMakeLists.txt b/java/test/CMakeLists.txt
index b76f572..937b129 100644
--- a/java/test/CMakeLists.txt
+++ b/java/test/CMakeLists.txt
@@ -38,6 +38,7 @@ set (HDF5_JAVA_TEST_SOURCES
     TestH5Ocreate
     TestH5Ocopy
     TestH5PL
+    TestH5VL
     TestH5Z
 )
 
diff --git a/java/test/Makefile.am b/java/test/Makefile.am
index 6635ef7..af99d92 100644
--- a/java/test/Makefile.am
+++ b/java/test/Makefile.am
@@ -69,6 +69,7 @@ noinst_JAVA = \
     TestH5Ocreate.java \
     TestH5Ocopy.java \
     TestH5PL.java \
+    TestH5VL.java \
     TestH5Z.java \
     TestH5E.java \
     TestH5Edefault.java \
diff --git a/java/test/TestH5VL.java b/java/test/TestH5VL.java
new file mode 100644
index 0000000..0397be1
--- /dev/null
+++ b/java/test/TestH5VL.java
@@ -0,0 +1,117 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+package test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+import hdf.hdf5lib.H5;
+import hdf.hdf5lib.HDF5Constants;
+import hdf.hdf5lib.exceptions.HDF5LibraryException;
+
+import java.io.File;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TestName;
+
+public class TestH5VL {
+    @Rule public TestName testname = new TestName();
+
+    private final void _deleteFile(String filename) {
+        File file = new File(filename);
+
+        if (file.exists()) {
+            try {file.delete();} catch (SecurityException e) {}
+        }
+    }
+
+    @Before
+    public void checkOpenIDs() {
+        assertTrue("H5 open ids is 0",H5.getOpenIDCount()==0);
+        System.out.print(testname.getMethodName());
+    }
+    @After
+    public void nextTestName() {
+        System.out.println();
+    }
+
+    @Test
+    public void testH5VLnative_init() {
+        try {
+            boolean is_registered;
+
+            is_registered = H5.H5VLis_connector_registered(HDF5Constants.H5VL_NATIVE_NAME);
+            assertTrue("H5.H5VLis_connector_registered H5VL_NATIVE_NAME", is_registered);
+
+            is_registered = H5.H5VLis_connector_registered("FAKE_VOL_NAME");
+            assertFalse("H5.H5VLis_connector_registered FAKE_VOL_NAME", is_registered);
+        }
+        catch (Throwable err) {
+            err.printStackTrace();
+            fail("H5.H5VLis_connector_registered " + err);
+        }
+    }
+
+    @Test
+    public void testH5VLget_connector_id() {
+        try {
+            long native_id = H5.H5VLget_connector_id(HDF5Constants.H5VL_NATIVE_NAME);
+            assertTrue("H5.H5VLget_connector_id H5VL_NATIVE_NAME", native_id >= 0);
+            assertEquals(HDF5Constants.H5VL_NATIVE, native_id);
+        }
+        catch (Throwable err) {
+            err.printStackTrace();
+            fail("H5.H5VLget_connector_id " + err);
+        }
+    }
+
+    @Test
+    public void testH5VLget_connector_name() {
+        String H5_FILE = "testFvl.h5";
+
+        long H5fid = H5.H5Fcreate(H5_FILE, HDF5Constants.H5F_ACC_TRUNC,
+                HDF5Constants.H5P_DEFAULT, HDF5Constants.H5P_DEFAULT);
+        H5.H5Fflush(H5fid, HDF5Constants.H5F_SCOPE_LOCAL);
+
+        try {
+            String native_name = H5.H5VLget_connector_name(H5fid);
+            assertTrue("H5.H5VLget_connector_name H5VL_NATIVE", native_name.compareToIgnoreCase(HDF5Constants.H5VL_NATIVE_NAME)==0);
+        }
+        catch (Throwable err) {
+            err.printStackTrace();
+            fail("H5.H5VLget_connector_name " + err);
+        }
+        finally {
+            if (H5fid > 0) {
+                try {H5.H5Fclose(H5fid);} catch (Exception ex) {}
+            }
+            _deleteFile(H5_FILE);
+        }
+    }
+
+    @Test(expected = HDF5LibraryException.class)
+    public void testH5VLclose_NegativeID() throws Throwable {
+        H5.H5VLclose(-1);
+    }
+
+    @Test(expected = HDF5LibraryException.class)
+    public void testH5VLunregister_connector_NegativeID() throws Throwable {
+        H5.H5VLunregister_connector(-1);
+    }
+}
+
diff --git a/java/test/junit.sh.in b/java/test/junit.sh.in
index 350fb7b..add1af4 100644
--- a/java/test/junit.sh.in
+++ b/java/test/junit.sh.in
@@ -101,6 +101,7 @@ $HDFTEST_HOME/testfiles/JUnit-TestH5Obasic.txt
 $HDFTEST_HOME/testfiles/JUnit-TestH5Ocreate.txt
 $HDFTEST_HOME/testfiles/JUnit-TestH5Ocopy.txt
 $HDFTEST_HOME/testfiles/JUnit-TestH5PL.txt
+$HDFTEST_HOME/testfiles/JUnit-TestH5VL.txt
 $HDFTEST_HOME/testfiles/JUnit-TestH5Z.txt
 $HDFTEST_HOME/testfiles/JUnit-TestH5E.txt
 $HDFTEST_HOME/testfiles/JUnit-TestH5Edefault.txt
@@ -989,6 +990,27 @@ else
     test yes = "$verbose" && $DIFF JUnit-TestH5PL.txt JUnit-TestH5PL.out |sed 's/^/    /'
 fi
 
+echo "$JAVAEXE $JAVAEXEFLAGS -Xmx1024M -Dorg.slf4j.simpleLogger.defaultLog=trace -Djava.library.path=$BLDLIBDIR -cp $CLASSPATH -ea org.junit.runner.JUnitCore test.TestH5VL"
+TESTING JUnit-TestH5VL
+($RUNSERIAL $JAVAEXE $JAVAEXEFLAGS -Xmx1024M -Dorg.slf4j.simpleLogger.defaultLog=trace -Djava.library.path=$BLDLIBDIR -cp $CLASSPATH -ea org.junit.runner.JUnitCore test.TestH5VL > JUnit-TestH5VL.ext)
+
+# Extract file name, line number, version and thread IDs because they may be different
+sed -e 's/thread [0-9]*/thread (IDs)/' -e 's/: .*\.c /: (file name) /' \
+    -e 's/line [0-9]*/line (number)/' \
+    -e 's/Time: [0-9]*\.[0-9]*/Time:  XXXX/' \
+    -e 's/v[1-9]*\.[0-9]*\./version (number)\./' \
+    -e 's/[1-9]*\.[0-9]*\.[0-9]*[^)]*/version (number)/' \
+    JUnit-TestH5VL.ext > JUnit-TestH5VL.out
+
+if diff JUnit-TestH5VL.out JUnit-TestH5VL.txt > /dev/null; then
+    echo "  PASSED      JUnit-TestH5VL"
+else
+    echo "**FAILED**    JUnit-TestH5VL"
+    echo "    Expected result differs from actual result"
+    nerrors="`expr $nerrors + 1`"
+    test yes = "$verbose" && $DIFF JUnit-TestH5VL.txt JUnit-TestH5VL.out |sed 's/^/    /'
+fi
+
 echo "$JAVAEXE $JAVAEXEFLAGS -Xmx1024M -Dorg.slf4j.simpleLogger.defaultLog=trace -Djava.library.path=$BLDLIBDIR -cp $CLASSPATH -ea org.junit.runner.JUnitCore test.TestH5Z"
 TESTING JUnit-TestH5Z
 ($RUNSERIAL $JAVAEXE $JAVAEXEFLAGS -Xmx1024M -Dorg.slf4j.simpleLogger.defaultLog=trace -Djava.library.path=$BLDLIBDIR -cp $CLASSPATH -ea org.junit.runner.JUnitCore test.TestH5Z > JUnit-TestH5Z.ext)
diff --git a/java/test/testfiles/JUnit-TestH5VL.txt b/java/test/testfiles/JUnit-TestH5VL.txt
new file mode 100644
index 0000000..caadf26
--- /dev/null
+++ b/java/test/testfiles/JUnit-TestH5VL.txt
@@ -0,0 +1,11 @@
+JUnit version 4.11
+.testH5VLget_connector_id
+.testH5VLnative_init
+.testH5VLget_connector_name
+.testH5VLclose_NegativeID
+.testH5VLunregister_connector_NegativeID
+
+Time:  XXXX
+
+OK (5 tests)
+
diff --git a/release_docs/INSTALL_CMake.txt b/release_docs/INSTALL_CMake.txt
index edd876a..26cf3ce 100644
--- a/release_docs/INSTALL_CMake.txt
+++ b/release_docs/INSTALL_CMake.txt
@@ -641,7 +641,6 @@ HDF5_GENERATE_HEADERS          "Rebuild Generated Files"
 HDF5_BUILD_GENERATORS          "Build Test Generators"                                        OFF
 HDF5_JAVA_PACK_JRE             "Package a JRE installer directory"                            OFF
 HDF5_MEMORY_ALLOC_SANITY_CHECK "Indicate that internal memory allocation sanity checks are enabled" OFF
-HDF5_METADATA_TRACE_FILE       "Enable metadata trace file collection"                        OFF
 HDF5_NO_PACKAGES               "Do not include CPack Packaging"                               OFF
 HDF5_PACK_EXAMPLES             "Package the HDF5 Library Examples Compressed File"            OFF
 HDF5_PACK_MACOSX_FRAMEWORK     "Package the HDF5 Library in a Frameworks"                     OFF
@@ -651,6 +650,7 @@ HDF5_PACKAGE_EXTLIBS           "CPACK - include external libraries"
 HDF5_STRICT_FORMAT_CHECKS      "Whether to perform strict file format checks"                 OFF
 HDF_TEST_EXPRESS               "Control testing framework (0-3)"                              "0"
 HDF5_TEST_VFD                  "Execute tests with different VFDs"                            OFF
+HDF5_TEST_VOL                  "Execute tests with different VOL connectors"                  OFF
 HDF5_USE_16_API_DEFAULT        "Use the HDF5 1.6.x API by default"                            OFF
 HDF5_USE_18_API_DEFAULT        "Use the HDF5 1.8.x API by default"                            OFF
 HDF5_USE_110_API_DEFAULT       "Use the HDF5 1.10.x API by default"                           OFF
diff --git a/release_docs/INSTALL_parallel b/release_docs/INSTALL_parallel
index f32fffc..d3d7830 100644
--- a/release_docs/INSTALL_parallel
+++ b/release_docs/INSTALL_parallel
@@ -102,7 +102,7 @@ qsub -I -q debug -l mppwidth=8
 - configure HDF5:
   RUNSERIAL="aprun -q -n 1" RUNPARALLEL="aprun -q -n 6" FC=ftn CC=cc /path/to/source/configure --enable-fortran --enable-parallel --disable-shared
 
-  RUNSERIAL and RUNPARALLEL tells the library how it should launch programs that are part of the build procedure.
+  RUNSERIAL and RUNPARALLEL tell the library how it should launch programs that are part of the build procedure.
 
 - Compile HDF5: 
   gmake
@@ -155,12 +155,16 @@ to run a parallel application on one processor and on many processors. If the
 compiler is `mpicc' and the user hasn't specified values for RUNSERIAL and
 RUNPARALLEL then configure chooses `mpiexec' from the same directory as `mpicc':
 
-    RUNSERIAL:    /usr/local/mpi/bin/mpiexec -np 1
-    RUNPARALLEL:  /usr/local/mpi/bin/mpiexec -np $${NPROCS:=6}
+    RUNSERIAL:    mpiexec -n 1
+    RUNPARALLEL:  mpiexec -n $${NPROCS:=6}
 
 The `$${NPROCS:=6}' will be substituted with the value of the NPROCS
 environment variable at the time `make check' is run (or the value 6).
 
+Note that some MPI implementations (e.g. OpenMPI 4.0) disallow oversubscribing
+nodes by default so you'll have to either set NPROCS equal to the number of
+processors available (or fewer) or redefine RUNPARALLEL with appropriate
+flag(s) (--oversubscribe in OpenMPI).
 
 4. Parallel test suite
 ----------------------
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 778505f..40b64f5 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -39,7 +39,6 @@ IDE_GENERATED_PROPERTIES ("H5A" "${H5A_HDRS}" "${H5A_SOURCES}" )
 set (H5AC_SOURCES
     ${HDF5_SRC_DIR}/H5AC.c
     ${HDF5_SRC_DIR}/H5ACdbg.c
-    ${HDF5_SRC_DIR}/H5AClog.c
     ${HDF5_SRC_DIR}/H5ACmpio.c
     ${HDF5_SRC_DIR}/H5ACproxy_entry.c
 )
@@ -81,6 +80,8 @@ set (H5C_SOURCES
     ${HDF5_SRC_DIR}/H5Cepoch.c
     ${HDF5_SRC_DIR}/H5Cimage.c
     ${HDF5_SRC_DIR}/H5Clog.c
+    ${HDF5_SRC_DIR}/H5Clog_json.c
+    ${HDF5_SRC_DIR}/H5Clog_trace.c
     ${HDF5_SRC_DIR}/H5Cmpio.c
     ${HDF5_SRC_DIR}/H5Cprefetched.c
     ${HDF5_SRC_DIR}/H5Cquery.c
@@ -628,6 +629,13 @@ set (H5VL_SOURCES
     ${HDF5_SRC_DIR}/H5VLcallback.c
     ${HDF5_SRC_DIR}/H5VLint.c
     ${HDF5_SRC_DIR}/H5VLnative.c
+    ${HDF5_SRC_DIR}/H5VLnative_attr.c
+    ${HDF5_SRC_DIR}/H5VLnative_dataset.c
+    ${HDF5_SRC_DIR}/H5VLnative_datatype.c
+    ${HDF5_SRC_DIR}/H5VLnative_file.c
+    ${HDF5_SRC_DIR}/H5VLnative_group.c
+    ${HDF5_SRC_DIR}/H5VLnative_link.c
+    ${HDF5_SRC_DIR}/H5VLnative_object.c
     ${HDF5_SRC_DIR}/H5VLpassthru.c
 )
 set (H5VL_HDRS
@@ -772,6 +780,7 @@ set (H5_PRIVATE_HEADERS
     ${HDF5_SRC_DIR}/H5B2pkg.h
     ${HDF5_SRC_DIR}/H5B2private.h
 
+    ${HDF5_SRC_DIR}/H5Clog.h
     ${HDF5_SRC_DIR}/H5Cpkg.h
     ${HDF5_SRC_DIR}/H5Cprivate.h
 
@@ -869,6 +878,7 @@ set (H5_PRIVATE_HEADERS
 
     ${HDF5_SRC_DIR}/H5UCprivate.h
 
+    ${HDF5_SRC_DIR}/H5VLnative_private.h
     ${HDF5_SRC_DIR}/H5VLpkg.h
     ${HDF5_SRC_DIR}/H5VLprivate.h
 
diff --git a/src/H5A.c b/src/H5A.c
index 74b0148..1b804d9 100644
--- a/src/H5A.c
+++ b/src/H5A.c
@@ -1201,10 +1201,16 @@ H5Arename(hid_t loc_id, const char *old_name, const char *new_name)
     H5TRACE3("e", "i*s*s", loc_id, old_name, new_name);
 
     /* check arguments */
-    if(!old_name || !new_name)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "name is nil")
     if(H5I_ATTR == H5I_get_type(loc_id))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
+    if(!old_name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "old attribute name cannot be NULL")
+    if(!*old_name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "old attribute name cannot be an empty string")
+    if(!new_name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "new attribute name cannot be NULL")
+    if(!*new_name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "new attribute name cannot be an empty string")
 
     /* Avoid thrashing things if the names are the same */
     if(HDstrcmp(old_name, new_name)) {
@@ -1360,7 +1366,7 @@ H5Aiterate2(hid_t loc_id, H5_index_t idx_type, H5_iter_order_t order,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
 
     /* Iterate over attributes */
-    if((ret_value = H5VL_attr_specific(vol_obj, &loc_params, H5VL_ATTR_ITER, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, idx_type, order, idx, op, op_data)) < 0)
+    if((ret_value = H5VL_attr_specific(vol_obj, &loc_params, H5VL_ATTR_ITER, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, (int)idx_type, (int)order, idx, op, op_data)) < 0)
         HERROR(H5E_ATTR, H5E_BADITER, "error iterating over attributes");
 
 done:
@@ -1448,7 +1454,7 @@ H5Aiterate_by_name(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
 
     /* Iterate over attributes */
-    if((ret_value = H5VL_attr_specific(vol_obj, &loc_params, H5VL_ATTR_ITER, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, idx_type, order, idx, op, op_data)) < 0)
+    if((ret_value = H5VL_attr_specific(vol_obj, &loc_params, H5VL_ATTR_ITER, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, (int)idx_type, (int)order, idx, op, op_data)) < 0)
         HERROR(H5E_ATTR, H5E_BADITER, "attribute iteration failed");
 
 done:
diff --git a/src/H5AC.c b/src/H5AC.c
index 9894e39..0a5411a 100644
--- a/src/H5AC.c
+++ b/src/H5AC.c
@@ -30,22 +30,24 @@
 /****************/
 
 #include "H5ACmodule.h"         /* This source code file is part of the H5AC module */
-#define H5F_FRIEND		/* Suppress error about including H5Fpkg            */
+#define H5C_FRIEND              /* Suppress error about including H5Cpkg            */
+#define H5F_FRIEND              /* Suppress error about including H5Fpkg            */
 
 
 /***********/
 /* Headers */
 /***********/
-#include "H5private.h"		/* Generic Functions			*/
-#include "H5ACpkg.h"		/* Metadata cache			*/
-#include "H5Cprivate.h"		/* Cache                                */
-#include "H5CXprivate.h"        /* API Contexts                         */
-#include "H5Eprivate.h"		/* Error handling		  	*/
-#include "H5Fpkg.h"		/* Files				*/
-#include "H5FDprivate.h"	/* File drivers				*/
-#include "H5Iprivate.h"		/* IDs			  		*/
-#include "H5Pprivate.h"         /* Property lists                       */
-#include "H5SLprivate.h"        /* Skip Lists                           */
+#include "H5private.h"          /* Generic Functions                        */
+#include "H5ACpkg.h"            /* Metadata cache                           */
+#include "H5Clog.h"             /* Cache logging                            */
+#include "H5Cpkg.h"             /* Cache                                    */
+#include "H5CXprivate.h"        /* API Contexts                             */
+#include "H5Eprivate.h"         /* Error handling                           */
+#include "H5Fpkg.h"             /* Files                                    */
+#include "H5FDprivate.h"        /* File drivers                             */
+#include "H5Iprivate.h"         /* IDs                                      */
+#include "H5Pprivate.h"         /* Property lists                           */
+#include "H5SLprivate.h"        /* Skip Lists                               */
 
 
 /****************/
@@ -128,7 +130,7 @@ static const H5AC_class_t *const H5AC_class_s[] = {
     H5AC_DRVRINFO,              /* (26) driver info block (supplements superblock) */
     H5AC_EPOCH_MARKER,          /* (27) epoch marker - always internal to cache */
     H5AC_PROXY_ENTRY,           /* (28) cache entry proxy               */
-    H5AC_PREFETCHED_ENTRY  	/* (29) prefetched entry - always internal to cache */
+    H5AC_PREFETCHED_ENTRY       /* (29) prefetched entry - always internal to cache */
 };
 
 
@@ -178,13 +180,16 @@ H5AC__init_package(void)
 
 #ifdef H5_HAVE_PARALLEL
     /* check whether to enable strict collective function calling
-       sanity checks using MPI barriers */
+     * sanity checks using MPI barriers
+     */
     {
         const char *s;  /* String for environment variables */
 
         s = HDgetenv("H5_COLL_API_SANITY_CHECK");
-        if(s && HDisdigit(*s))
-            H5_coll_api_sanity_check_g = (hbool_t)HDstrtol(s, NULL, 0);
+        if(s && HDisdigit(*s)) {
+            long env_val = HDstrtol(s, NULL, 0);
+            H5_coll_api_sanity_check_g = (0 == env_val) ? FALSE : TRUE;
+        }
     }
 #endif /* H5_HAVE_PARALLEL */
 
@@ -403,15 +408,13 @@ H5AC_create(const H5F_t *f, H5AC_cache_config_t *config_ptr, H5AC_cache_image_co
             HGOTO_ERROR(H5E_CACHE, H5E_CANTALLOC, FAIL, "H5C_set_prefix() failed")
 #endif /* H5_HAVE_PARALLEL */
 
-    /* Turn on metadata cache logging, if being used */
-    if(H5F_USE_MDC_LOGGING(f)) {
-        if(H5C_set_up_logging(f->shared->cache, H5F_MDC_LOG_LOCATION(f), H5F_START_MDC_LOG_ON_ACCESS(f)) < 0)
-            HGOTO_ERROR(H5E_CACHE, H5E_CANTINIT, FAIL, "mdc logging setup failed")
-
-        /* Write the log header regardless of current logging status */
-        if(H5AC__write_create_cache_log_msg(f->shared->cache) < 0)
-            HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to emit log message")
-    } /* end if */
+    /* Turn on metadata cache logging, if being used
+     * This will be JSON until we create a special API call. Trace output
+     * is generated when logging is controlled by the struct.
+     */
+    if(H5F_USE_MDC_LOGGING(f))
+        if(H5C_log_set_up(f->shared->cache, H5F_MDC_LOG_LOCATION(f), H5C_LOG_STYLE_JSON, H5F_START_MDC_LOG_ON_ACCESS(f)) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "mdc logging setup failed")
 
     /* Set the cache parameters */
     if(H5AC_set_cache_auto_resize_config(f->shared->cache, config_ptr) < 0)
@@ -431,6 +434,11 @@ H5AC_create(const H5F_t *f, H5AC_cache_config_t *config_ptr, H5AC_cache_image_co
         HGOTO_ERROR(H5E_CACHE, H5E_CANTSET, FAIL, "auto resize configuration failed")
 
 done:
+    /* If currently logging, generate a message */
+    if(f->shared->cache->log_info->logging)
+        if(H5C_log_write_create_cache_msg(f->shared->cache, ret_value) < 0)
+            HDONE_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
 #ifdef H5_HAVE_PARALLEL
     /* if there is a failure, try to tidy up the auxiliary structure */
     if(ret_value < 0) {
@@ -469,6 +477,8 @@ done:
 herr_t
 H5AC_dest(H5F_t *f)
 {
+    hbool_t log_enabled;             /* TRUE if logging was set up */
+    hbool_t curr_logging;            /* TRUE if currently logging */
 #ifdef H5_HAVE_PARALLEL
     H5AC_aux_t * aux_ptr = NULL;
 #endif /* H5_HAVE_PARALLEL */
@@ -486,18 +496,16 @@ H5AC_dest(H5F_t *f)
     H5AC_stats(f);
 #endif /* H5AC_DUMP_STATS_ON_CLOSE */
 
-#if H5AC__TRACE_FILE_ENABLED
-    if(H5AC__close_trace_file(f->shared->cache) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "H5AC__close_trace_file() failed")
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
-    if(H5F_USE_MDC_LOGGING(f)) {
-        /* Write the log footer regardless of current logging status */
-        if(H5AC__write_destroy_cache_log_msg(f->shared->cache) < 0)
-            HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to emit log message")
-        if(H5C_tear_down_logging(f->shared->cache) < 0)
-            HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "mdc logging tear-down failed")
-    } /* end if */
+    /* Check if log messages are being emitted */
+    if(H5C_get_logging_status(f->shared->cache, &log_enabled, &curr_logging) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to get logging status")
+    if(log_enabled && curr_logging)
+        if(H5C_log_write_destroy_cache_msg(f->shared->cache) < 0)
+            HDONE_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+    /* Tear down logging */
+    if(log_enabled)
+        if(H5C_log_tear_down(f->shared->cache) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "mdc logging tear-down failed")
 
 #ifdef H5_HAVE_PARALLEL
     /* destroying the cache, so clear all collective entries */
@@ -565,8 +573,6 @@ done:
 herr_t
 H5AC_evict(H5F_t *f)
 {
-    hbool_t log_enabled;             /* TRUE if logging was set up */
-    hbool_t curr_logging;            /* TRUE if currently logging */
     herr_t ret_value = SUCCEED;      /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
@@ -576,10 +582,6 @@ H5AC_evict(H5F_t *f)
     HDassert(f->shared);
     HDassert(f->shared->cache);
 
-    /* Check if log messages are being emitted */
-    if(H5C_get_logging_status(f->shared->cache, &log_enabled, &curr_logging) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to get logging status")
-
     /* Evict all entries in the cache except the pinned superblock entry */
     if(H5C_evict(f) < 0)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTFREE, FAIL, "can't evict cache")
@@ -587,9 +589,9 @@ H5AC_evict(H5F_t *f)
 done:
 
     /* If currently logging, generate a message */
-    if(curr_logging)
-        if(H5AC__write_evict_cache_log_msg(f->shared->cache, ret_value) < 0)
-            HDONE_ERROR(H5E_CACHE, H5E_LOGFAIL, FAIL, "unable to emit log message")
+    if(f->shared->cache->log_info->logging)
+        if(H5C_log_write_evict_cache_msg(f->shared->cache, ret_value) < 0)
+            HDONE_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5AC_evict() */
@@ -613,12 +615,6 @@ herr_t
 H5AC_expunge_entry(H5F_t *f, const H5AC_class_t *type, haddr_t addr,
     unsigned flags)
 {
-#if H5AC__TRACE_FILE_ENABLED
-    char                trace[128] = "";
-    FILE *              trace_file_ptr = NULL;
-#endif /* H5AC__TRACE_FILE_ENABLED */
-    hbool_t log_enabled;              /* TRUE if logging was set up */
-    hbool_t curr_logging;             /* TRUE if currently logging */
     herr_t  ret_value = SUCCEED;      /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
@@ -631,36 +627,14 @@ H5AC_expunge_entry(H5F_t *f, const H5AC_class_t *type, haddr_t addr,
     HDassert(type->serialize);
     HDassert(H5F_addr_defined(addr));
 
-    /* Check if log messages are being emitted */
-    if(H5C_get_logging_status(f->shared->cache, &log_enabled, &curr_logging) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to get logging status")
-
-#if H5AC__TRACE_FILE_ENABLED
-{
-    H5AC_t * cache_ptr = f->shared->cache;
-
-    /* For the expunge entry call, only the addr, and type id are really
-     * necessary in the trace file.  Write the return value to catch occult
-     * errors.
-     */
-    if(NULL != (trace_file_ptr = H5C_get_trace_file_ptr(cache_ptr)))
-        sprintf(trace, "%s 0x%lx %d", FUNC, (unsigned long)addr, (int)(type->id));
-}
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     if(H5C_expunge_entry(f, type, addr, flags) < 0)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTEXPUNGE, FAIL, "H5C_expunge_entry() failed")
 
 done:
-#if H5AC__TRACE_FILE_ENABLED
-    if(trace_file_ptr != NULL)
-	HDfprintf(trace_file_ptr, "%s %d\n", trace, (int)ret_value);
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     /* If currently logging, generate a message */
-    if(curr_logging)
-        if(H5AC__write_expunge_entry_log_msg(f->shared->cache, addr, type->id, ret_value) < 0)
-            HDONE_ERROR(H5E_CACHE, H5E_LOGFAIL, FAIL, "unable to emit log message")
+    if(f->shared->cache->log_info->logging)
+        if(H5C_log_write_expunge_entry_msg(f->shared->cache, addr, type->id, ret_value) < 0)
+            HDONE_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5AC_expunge_entry() */
@@ -689,12 +663,6 @@ done:
 herr_t
 H5AC_flush(H5F_t *f)
 {
-#if H5AC__TRACE_FILE_ENABLED
-    char 	  trace[128] = "";
-    FILE *	  trace_file_ptr = NULL;
-#endif /* H5AC__TRACE_FILE_ENABLED */
-    hbool_t log_enabled;              /* TRUE if logging was set up */
-    hbool_t curr_logging;             /* TRUE if currently logging */
     herr_t ret_value = SUCCEED;      /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
@@ -704,18 +672,6 @@ H5AC_flush(H5F_t *f)
     HDassert(f->shared);
     HDassert(f->shared->cache);
 
-    /* Check if log messages are being emitted */
-    if(H5C_get_logging_status(f->shared->cache, &log_enabled, &curr_logging) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to get logging status")
-
-#if H5AC__TRACE_FILE_ENABLED
-    /* For the flush, only the flags are really necessary in the trace file.
-     * Write the result to catch occult errors.
-     */
-    if(NULL != (trace_file_ptr = H5C_get_trace_file_ptr(cache_ptr)))
-	sprintf(trace, "%s", FUNC);
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
 #ifdef H5_HAVE_PARALLEL
     /* flushing the cache, so clear all collective entries */
     if(H5C_clear_coll_entries(f->shared->cache, FALSE) < 0)
@@ -732,15 +688,10 @@ H5AC_flush(H5F_t *f)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "Can't flush cache")
 
 done:
-#if H5AC__TRACE_FILE_ENABLED
-    if(trace_file_ptr != NULL)
-        HDfprintf(trace_file_ptr, "%s %d\n", trace, (int)ret_value);
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     /* If currently logging, generate a message */
-    if(curr_logging)
-        if(H5AC__write_flush_cache_log_msg(f->shared->cache, ret_value) < 0)
-            HDONE_ERROR(H5E_CACHE, H5E_LOGFAIL, FAIL, "unable to emit log message")
+    if(f->shared->cache->log_info->logging)
+        if(H5C_log_write_flush_cache_msg(f->shared->cache, ret_value) < 0)
+            HDONE_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5AC_flush() */
@@ -873,13 +824,6 @@ herr_t
 H5AC_insert_entry(H5F_t *f, const H5AC_class_t *type, haddr_t addr, void *thing,
     unsigned int flags)
 {
-#if H5AC__TRACE_FILE_ENABLED
-    char          	trace[128] = "";
-    size_t              trace_entry_size = 0;
-    FILE *        	trace_file_ptr = NULL;
-#endif /* H5AC__TRACE_FILE_ENABLED */
-    hbool_t log_enabled;             /* TRUE if logging was set up */
-    hbool_t curr_logging;            /* TRUE if currently logging */
     herr_t ret_value = SUCCEED;      /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
@@ -893,26 +837,9 @@ H5AC_insert_entry(H5F_t *f, const H5AC_class_t *type, haddr_t addr, void *thing,
     HDassert(H5F_addr_defined(addr));
     HDassert(thing);
 
-    /* Check if log messages are being emitted */
-    if(H5C_get_logging_status(f->shared->cache, &log_enabled, &curr_logging) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to get logging status")
-
     /* Check for invalid access request */
     if(0 == (H5F_INTENT(f) & H5F_ACC_RDWR))
-	HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, FAIL, "no write intent on file")
-
-#if H5AC__TRACE_FILE_ENABLED
-    /* For the insert, only the addr, size, type id and flags are really
-     * necessary in the trace file.  Write the result to catch occult
-     * errors.
-     *
-     * Note that some data is not available right now -- put what we can
-     * in the trace buffer now, and fill in the rest at the end.
-     */
-    if(NULL != (trace_file_ptr = H5C_get_trace_file_ptr(cache_ptr)))
-        sprintf(trace, "%s 0x%lx %d 0x%x", FUNC, (unsigned long)addr, type->id,
-            flags);
-#endif /* H5AC__TRACE_FILE_ENABLED */
+        HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, FAIL, "no write intent on file")
 
 #if H5AC_DO_TAGGING_SANITY_CHECKS
     if(!H5C_get_ignore_tags(f->shared->cache) && H5AC__verify_tag(type) < 0)
@@ -923,12 +850,6 @@ H5AC_insert_entry(H5F_t *f, const H5AC_class_t *type, haddr_t addr, void *thing,
     if(H5C_insert_entry(f, type, addr, thing, flags) < 0)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTINS, FAIL, "H5C_insert_entry() failed")
 
-#if H5AC__TRACE_FILE_ENABLED
-    if(trace_file_ptr != NULL)
-        /* make note of the entry size */
-        trace_entry_size = ((H5C_cache_entry_t *)thing)->size;
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
 #ifdef H5_HAVE_PARALLEL
 {
     H5AC_aux_t *aux_ptr;
@@ -947,14 +868,10 @@ H5AC_insert_entry(H5F_t *f, const H5AC_class_t *type, haddr_t addr, void *thing,
 #endif /* H5_HAVE_PARALLEL */
 
 done:
-#if H5AC__TRACE_FILE_ENABLED
-    if(trace_file_ptr != NULL)
-	HDfprintf(trace_file_ptr, "%s %d %d\n", trace, (int)trace_entry_size, (int)ret_value);
-#endif /* H5AC__TRACE_FILE_ENABLED */
     /* If currently logging, generate a message */
-    if(curr_logging)
-        if(H5AC__write_insert_entry_log_msg(f->shared->cache, addr, type->id, flags, ((H5C_cache_entry_t *)thing)->size, ret_value) < 0)
-            HDONE_ERROR(H5E_CACHE, H5E_LOGFAIL, FAIL, "unable to emit log message")
+    if(f->shared->cache->log_info->logging)
+        if(H5C_log_write_insert_entry_msg(f->shared->cache, addr, type->id, flags, ((H5C_cache_entry_t *)thing)->size, ret_value) < 0)
+            HDONE_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5AC_insert_entry() */
@@ -1011,12 +928,6 @@ done:
 herr_t
 H5AC_mark_entry_dirty(void *thing)
 {
-#if H5AC__TRACE_FILE_ENABLED
-    char          	trace[128] = "";
-    FILE *        	trace_file_ptr = NULL;
-#endif /* H5AC__TRACE_FILE_ENABLED */
-    hbool_t log_enabled;              /* TRUE if logging was set up */
-    hbool_t curr_logging;             /* TRUE if currently logging */
     H5AC_info_t *entry_ptr = NULL;    /* Pointer to the cache entry */
     H5C_t *cache_ptr = NULL;          /* Pointer to the entry's associated metadata cache */
     herr_t ret_value = SUCCEED;       /* Return value */
@@ -1030,19 +941,6 @@ H5AC_mark_entry_dirty(void *thing)
     entry_ptr = (H5AC_info_t *)thing;
     cache_ptr = entry_ptr->cache_ptr;
 
-#if H5AC__TRACE_FILE_ENABLED
-    /* For the mark pinned or protected entry dirty call, only the addr
-     * is really necessary in the trace file.  Write the result to catch
-     * occult errors.
-     */
-    if(NULL != (trace_file_ptr = H5C_get_trace_file_ptr_from_entry(thing)))
-        sprintf(trace, "%s 0x%lx", FUNC, (unsigned long)(entry_ptr->addr));
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
-    /* Check if log messages are being emitted */
-    if(H5C_get_logging_status(cache_ptr, &log_enabled, &curr_logging) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to get logging status")
-
 #ifdef H5_HAVE_PARALLEL
 {
     H5AC_aux_t *aux_ptr;
@@ -1059,15 +957,10 @@ H5AC_mark_entry_dirty(void *thing)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTMARKDIRTY, FAIL, "can't mark pinned or protected entry dirty")
 
 done:
-#if H5AC__TRACE_FILE_ENABLED
-    if(trace_file_ptr)
-	HDfprintf(trace_file_ptr, "%s %d\n", trace, (int)ret_value);
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     /* If currently logging, generate a message */
-    if(curr_logging)
-        if(H5AC__write_mark_dirty_entry_log_msg(cache_ptr, entry_ptr, ret_value) < 0)
-            HDONE_ERROR(H5E_CACHE, H5E_LOGFAIL, FAIL, "unable to emit log message")
+    if(cache_ptr->log_info->logging)
+        if(H5C_log_write_mark_entry_dirty_msg(cache_ptr, entry_ptr, ret_value) < 0)
+            HDONE_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5AC_mark_entry_dirty() */
@@ -1076,7 +969,7 @@ done:
 /*-------------------------------------------------------------------------
  * Function:    H5AC_mark_entry_clean
  *
- * Purpose:	Mark a pinned entry as dirty.  The target
+ * Purpose:	Mark a pinned entry as clean.  The target
  * 		entry MUST be pinned.
  *
  * Return:      Non-negative on success/Negative on failure
@@ -1089,12 +982,6 @@ done:
 herr_t
 H5AC_mark_entry_clean(void *thing)
 {
-#if H5AC__TRACE_FILE_ENABLED
-    char          	trace[128] = "";
-    FILE *        	trace_file_ptr = NULL;
-#endif /* H5AC__TRACE_FILE_ENABLED */
-    hbool_t log_enabled;              /* TRUE if logging was set up */
-    hbool_t curr_logging;             /* TRUE if currently logging */
     H5AC_info_t *entry_ptr = NULL;    /* Pointer to the cache entry */
     H5C_t *cache_ptr = NULL;          /* Pointer to the entry's associated metadata cache */
     herr_t ret_value = SUCCEED;       /* Return value */
@@ -1104,23 +991,9 @@ H5AC_mark_entry_clean(void *thing)
     /* Sanity check */
     HDassert(thing);
 
-#if H5AC__TRACE_FILE_ENABLED
-    /* For the mark pinned or protected entry clean call, only the addr
-     * is really necessary in the trace file.  Write the result to catch
-     * occult errors.
-     */
-    if(NULL != (trace_file_ptr = H5C_get_trace_file_ptr_from_entry(thing)))
-        sprintf(trace, "%s 0x%lx", FUNC,
-	        (unsigned long)(((H5C_cache_entry_t *)thing)->addr));
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     entry_ptr = (H5AC_info_t *)thing;
     cache_ptr = entry_ptr->cache_ptr;
 
-    /* Check if log messages are being emitted */
-    if(H5C_get_logging_status(cache_ptr, &log_enabled, &curr_logging) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to get logging status")
-
 #ifdef H5_HAVE_PARALLEL
 {
     H5AC_aux_t *aux_ptr;
@@ -1137,15 +1010,10 @@ H5AC_mark_entry_clean(void *thing)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTMARKCLEAN, FAIL, "can't mark pinned or protected entry clean")
 
 done:
-#if H5AC__TRACE_FILE_ENABLED
-    if(trace_file_ptr)
-	HDfprintf(trace_file_ptr, "%s %d\n", trace, (int)ret_value);
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     /* If currently logging, generate a message */
-    if(curr_logging)
-        if(H5AC__write_mark_clean_entry_log_msg(cache_ptr, entry_ptr, ret_value) < 0)
-            HDONE_ERROR(H5E_CACHE, H5E_LOGFAIL, FAIL, "unable to emit log message")
+    if(cache_ptr->log_info->logging)
+        if(H5C_log_write_mark_entry_clean_msg(cache_ptr, entry_ptr, ret_value) < 0)
+            HDONE_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5AC_mark_entry_clean() */
@@ -1167,12 +1035,6 @@ done:
 herr_t
 H5AC_mark_entry_unserialized(void *thing)
 {
-#if H5AC__TRACE_FILE_ENABLED
-    char          	trace[128] = "";
-    FILE *        	trace_file_ptr = NULL;
-#endif /* H5AC__TRACE_FILE_ENABLED */
-    hbool_t log_enabled;              /* TRUE if logging was set up */
-    hbool_t curr_logging;             /* TRUE if currently logging */
     H5AC_info_t *entry_ptr = NULL;    /* Pointer to the cache entry */
     H5C_t *cache_ptr = NULL;          /* Pointer to the entry's associated metadata cache */
     herr_t ret_value = SUCCEED;       /* Return value */
@@ -1186,32 +1048,14 @@ H5AC_mark_entry_unserialized(void *thing)
     entry_ptr = (H5AC_info_t *)thing;
     cache_ptr = entry_ptr->cache_ptr;
 
-#if H5AC__TRACE_FILE_ENABLED
-    /* For the mark entry unserialized call, only the addr
-     * is really necessary in the trace file.  Write the result to catch
-     * occult errors.
-     */
-    if(NULL != (trace_file_ptr = H5C_get_trace_file_ptr_from_entry(thing)))
-        sprintf(trace, "%s 0x%lx", FUNC, (unsigned long)(entry_ptr->addr));
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
-    /* Check if log messages are being emitted */
-    if(H5C_get_logging_status(cache_ptr, &log_enabled, &curr_logging) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_CANTGET, FAIL, "unable to get logging status")
-
     if(H5C_mark_entry_unserialized(thing) < 0)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTMARKUNSERIALIZED, FAIL, "can't mark entry unserialized")
 
 done:
-#if H5AC__TRACE_FILE_ENABLED
-    if(trace_file_ptr)
-	HDfprintf(trace_file_ptr, "%s %d\n", trace, (int)ret_value);
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     /* If currently logging, generate a message */
-    if(curr_logging)
-        if(H5AC__write_mark_unserialized_entry_log_msg(cache_ptr, entry_ptr, ret_value) < 0)
-            HDONE_ERROR(H5E_CACHE, H5E_LOGFAIL, FAIL, "unable to emit log message")
+    if(cache_ptr->log_info->logging)
+        if(H5C_log_write_mark_unserialized_entry_msg(cache_ptr, entry_ptr, ret_value) < 0)
+            HDONE_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5AC_mark_entry_unserialized() */
@@ -1233,12 +1077,6 @@ done:
 herr_t
 H5AC_mark_entry_serialized(void *thing)
 {
-#if H5AC__TRACE_FILE_ENABLED
-    char          	trace[128] = "";
-    FILE *        	trace_file_ptr = NULL;
-#endif /* H5AC__TRACE_FILE_ENABLED */
-    hbool_t log_enabled;              /* TRUE if logging was set up */
-    hbool_t curr_logging;             /* TRUE if currently logging */
     H5AC_info_t *entry_ptr = NULL;    /* Pointer to the cache entry */
     H5C_t *cache_ptr = NULL;          /* Pointer to the entry's associated metadata cache */
     herr_t ret_value = SUCCEED;       /* Return value */
@@ -1248,36 +1086,17 @@ H5AC_mark_entry_serialized(void *thing)
     /* Sanity check */
     HDassert(thing);
 
-#if H5AC__TRACE_FILE_ENABLED
-    /* For the mark entry serializedn call, only the addr
-     * is really necessary in the trace file.  Write the result to catch
-     * occult errors.
-     */
-    if(NULL != (trace_file_ptr = H5C_get_trace_file_ptr_from_entry(thing)))
-        sprintf(trace, "%s 0x%lx", FUNC,
-	        (unsigned long)(((H5C_cache_entry_t *)thing)->addr));
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     entry_ptr = (H5AC_info_t *)thing;
     cache_ptr = entry_ptr->cache_ptr;
 
-    /* Check if log messages are being emitted */
-    if(H5C_get_logging_status(cache_ptr, &log_enabled, &curr_logging) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_CANTGET, FAIL, "unable to get logging status")
-
     if(H5C_mark_entry_serialized(thing) < 0)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTMARKSERIALIZED, FAIL, "can't mark entry serialized")
 
 done:
-#if H5AC__TRACE_FILE_ENABLED
-    if(trace_file_ptr)
-	HDfprintf(trace_file_ptr, "%s %d\n", trace, (int)ret_value);
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     /* If currently logging, generate a message */
-    if(curr_logging)
-        if(H5AC__write_mark_serialized_entry_log_msg(cache_ptr, entry_ptr, ret_value) < 0)
-            HDONE_ERROR(H5E_CACHE, H5E_LOGFAIL, FAIL, "unable to emit log message")
+    if(cache_ptr->log_info->logging)
+        if(H5C_log_write_mark_serialized_entry_msg(cache_ptr, entry_ptr, ret_value) < 0)
+            HDONE_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5AC_mark_entry_serialized() */
@@ -1300,15 +1119,9 @@ done:
 herr_t
 H5AC_move_entry(H5F_t *f, const H5AC_class_t *type, haddr_t old_addr, haddr_t new_addr)
 {
-#if H5AC__TRACE_FILE_ENABLED
-    char          	trace[128] = "";
-    FILE *        	trace_file_ptr = NULL;
-#endif /* H5AC__TRACE_FILE_ENABLED */
 #ifdef H5_HAVE_PARALLEL
     H5AC_aux_t        *aux_ptr;
 #endif /* H5_HAVE_PARALLEL */
-    hbool_t log_enabled;           /* TRUE if logging was set up */
-    hbool_t curr_logging;          /* TRUE if currently logging */
     herr_t ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
@@ -1321,20 +1134,6 @@ H5AC_move_entry(H5F_t *f, const H5AC_class_t *type, haddr_t old_addr, haddr_t ne
     HDassert(H5F_addr_defined(new_addr));
     HDassert(H5F_addr_ne(old_addr, new_addr));
 
-    /* Check if log messages are being emitted */
-    if(H5C_get_logging_status(f->shared->cache, &log_enabled, &curr_logging) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to get logging status")
-
-#if H5AC__TRACE_FILE_ENABLED
-    /* For the move call, only the old addr and new addr are really
-     * necessary in the trace file.  Include the type id so we don't have to
-     * look it up.  Also write the result to catch occult errors.
-     */
-    if(NULL != (trace_file_ptr = H5C_get_trace_file_ptr(cache_ptr)))
-        sprintf(trace, "%s 0x%lx 0x%lx %d", FUNC, (unsigned long)old_addr,
-		(unsigned long)new_addr, (int)(type->id));
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
 #ifdef H5_HAVE_PARALLEL
     /* Log moving the entry */
     if(NULL != (aux_ptr = (H5AC_aux_t *)H5C_get_aux_ptr(f->shared->cache)))
@@ -1353,15 +1152,10 @@ H5AC_move_entry(H5F_t *f, const H5AC_class_t *type, haddr_t old_addr, haddr_t ne
 #endif /* H5_HAVE_PARALLEL */
 
 done:
-#if H5AC__TRACE_FILE_ENABLED
-    if(trace_file_ptr != NULL)
-	HDfprintf(trace_file_ptr, "%s %d\n", trace, (int)ret_value);
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     /* If currently logging, generate a message */
-    if(curr_logging)
-        if(H5AC__write_move_entry_log_msg(f->shared->cache, old_addr, new_addr, type->id, ret_value) < 0)
-            HDONE_ERROR(H5E_CACHE, H5E_LOGFAIL, FAIL, "unable to emit log message")
+    if(f->shared->cache->log_info->logging)
+        if(H5C_log_write_move_entry_msg(f->shared->cache, old_addr, new_addr, type->id, ret_value) < 0)
+            HDONE_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5AC_move_entry() */
@@ -1383,12 +1177,6 @@ done:
 herr_t
 H5AC_pin_protected_entry(void *thing)
 {
-#if H5AC__TRACE_FILE_ENABLED
-    char        trace[128] = "";
-    FILE *      trace_file_ptr = NULL;
-#endif /* H5AC__TRACE_FILE_ENABLED */
-    hbool_t log_enabled;                /* TRUE if logging was set up */
-    hbool_t curr_logging;               /* TRUE if currently logging */
     H5AC_info_t *entry_ptr = NULL;      /* Pointer to the cache entry */
     H5C_t *cache_ptr = NULL;            /* Pointer to the entry's associated metadata cache */
     herr_t      ret_value = SUCCEED;    /* Return value */
@@ -1398,37 +1186,19 @@ H5AC_pin_protected_entry(void *thing)
     /* Sanity check */
     HDassert(thing);
 
-#if H5AC__TRACE_FILE_ENABLED
-    /* For the pin protected entry call, only the addr is really necessary
-     * in the trace file.  Also write the result to catch occult errors.
-     */
-    if(NULL != (trace_file_ptr = H5C_get_trace_file_ptr_from_entry(thing)))
-        sprintf(trace, "%s 0x%lx", FUNC,
-	        (unsigned long)(((H5C_cache_entry_t *)thing)->addr));
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     entry_ptr = (H5AC_info_t *)thing;
     cache_ptr = entry_ptr->cache_ptr;
     HDassert(cache_ptr);
 
-    /* Check if log messages are being emitted */
-    if(H5C_get_logging_status(cache_ptr, &log_enabled, &curr_logging) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to get logging status")
-
     /* Pin entry */
     if(H5C_pin_protected_entry(thing) < 0)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTPIN, FAIL, "can't pin entry")
 
 done:
-#if H5AC__TRACE_FILE_ENABLED
-    if(trace_file_ptr)
-	HDfprintf(trace_file_ptr, "%s %d\n", trace, (int)ret_value);
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     /* If currently logging, generate a message */
-    if(curr_logging)
-        if(H5AC__write_pin_entry_log_msg(cache_ptr, entry_ptr, ret_value) < 0)
-            HDONE_ERROR(H5E_CACHE, H5E_LOGFAIL, FAIL, "unable to emit log message")
+    if(cache_ptr->log_info->logging)
+        if(H5C_log_write_pin_entry_msg(cache_ptr, entry_ptr, ret_value) < 0)
+            HDONE_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5AC_pin_protected_entry() */
@@ -1488,12 +1258,6 @@ done:
 herr_t
 H5AC_create_flush_dependency(void * parent_thing, void * child_thing)
 {
-#if H5AC__TRACE_FILE_ENABLED
-    char        trace[128] = "";
-    FILE *      trace_file_ptr = NULL;
-#endif /* H5AC__TRACE_FILE_ENABLED */
-    hbool_t log_enabled;                /* TRUE if logging was set up */
-    hbool_t curr_logging;               /* TRUE if currently logging */
     H5AC_info_t *entry_ptr = NULL;      /* Pointer to the cache entry */
     H5C_t *cache_ptr = NULL;            /* Pointer to the entry's associated metadata cache */
     herr_t      ret_value = SUCCEED;    /* Return value */
@@ -1504,35 +1268,19 @@ H5AC_create_flush_dependency(void * parent_thing, void * child_thing)
     HDassert(parent_thing);
     HDassert(child_thing);
 
-#if H5AC__TRACE_FILE_ENABLED
-    if(NULL != (trace_file_ptr = H5C_get_trace_file_ptr_from_entry(parent_thing)))
-        sprintf(trace, "%s %lx %lx", FUNC,
-	        (unsigned long)(((H5C_cache_entry_t *)parent_thing)->addr),
-	        (unsigned long)(((H5C_cache_entry_t *)child_thing)->addr));
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     entry_ptr = (H5AC_info_t *)parent_thing;
     cache_ptr = entry_ptr->cache_ptr;
     HDassert(cache_ptr);
 
-    /* Check if log messages are being emitted */
-    if(H5C_get_logging_status(cache_ptr, &log_enabled, &curr_logging) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to get logging status")
-
     /* Create the flush dependency */
     if(H5C_create_flush_dependency(parent_thing, child_thing) < 0)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTDEPEND, FAIL, "H5C_create_flush_dependency() failed")
 
 done:
-#if H5AC__TRACE_FILE_ENABLED
-    if(trace_file_ptr != NULL)
-	HDfprintf(trace_file_ptr, "%s %d\n", trace, (int)ret_value);
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     /* If currently logging, generate a message */
-    if(curr_logging)
-        if(H5AC__write_create_fd_log_msg(cache_ptr, (H5AC_info_t *)parent_thing, (H5AC_info_t *)child_thing, ret_value) < 0)
-            HDONE_ERROR(H5E_CACHE, H5E_LOGFAIL, FAIL, "unable to emit log message")
+    if(cache_ptr->log_info->logging)
+        if(H5C_log_write_create_fd_msg(cache_ptr, (H5AC_info_t *)parent_thing, (H5AC_info_t *)child_thing, ret_value) < 0)
+            HDONE_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5AC_create_flush_dependency() */
@@ -1566,14 +1314,7 @@ void *
 H5AC_protect(H5F_t *f, const H5AC_class_t *type, haddr_t addr, void *udata,
     unsigned flags)
 {
-#if H5AC__TRACE_FILE_ENABLED
-    char                trace[128] = "";
-    size_t		trace_entry_size = 0;
-    FILE *              trace_file_ptr = NULL;
-#endif /* H5AC__TRACE_FILE_ENABLED */
     void *              thing = NULL;           /* Pointer to native data structure for entry */
-    hbool_t             log_enabled;            /* TRUE if logging was set up */
-    hbool_t             curr_logging;           /* TRUE if currently logging */
     void *              ret_value = NULL;       /* Return value */
 
     FUNC_ENTER_NOAPI(NULL)
@@ -1586,10 +1327,6 @@ H5AC_protect(H5F_t *f, const H5AC_class_t *type, haddr_t addr, void *udata,
     HDassert(type->serialize);
     HDassert(H5F_addr_defined(addr));
 
-    /* Check if log messages are being emitted */
-    if(H5C_get_logging_status(f->shared->cache, &log_enabled, &curr_logging) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, NULL, "unable to get logging status")
-
     /* Check for unexpected flags -- H5C__FLUSH_COLLECTIVELY_FLAG
      * only permitted in the parallel case.
      */
@@ -1606,16 +1343,6 @@ H5AC_protect(H5F_t *f, const H5AC_class_t *type, haddr_t addr, void *udata,
     if((0 == (H5F_INTENT(f) & H5F_ACC_RDWR)) && (0 == (flags & H5C__READ_ONLY_FLAG)))
 	HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, NULL, "no write intent on file")
 
-#if H5AC__TRACE_FILE_ENABLED
-    /* For the protect call, only the addr, size, type id, and flags are 
-     * necessary in the trace file.  Also indicate whether the call was 
-     * successful to catch occult errors.
-     */
-    if(NULL != (trace_file_ptr = H5C_get_trace_file_ptr(cache_ptr)))
-        sprintf(trace, "%s 0x%lx %d 0x%x", FUNC, (unsigned long)addr,
-		(int)(type->id), flags);
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
 #if H5AC_DO_TAGGING_SANITY_CHECKS
     if(!H5C_get_ignore_tags(f->shared->cache) && H5AC__verify_tag(type) < 0)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTTAG, NULL, "Bad tag value")
@@ -1624,28 +1351,18 @@ H5AC_protect(H5F_t *f, const H5AC_class_t *type, haddr_t addr, void *udata,
     if(NULL == (thing = H5C_protect(f, type, addr, udata, flags)))
         HGOTO_ERROR(H5E_CACHE, H5E_CANTPROTECT, NULL, "H5C_protect() failed")
 
-#if H5AC__TRACE_FILE_ENABLED
-    if(trace_file_ptr != NULL)
-        /* Make note of the entry size */
-        trace_entry_size = ((H5C_cache_entry_t *)thing)->size;
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     /* Set return value */
     ret_value = thing;
 
 done:
-#if H5AC__TRACE_FILE_ENABLED
-    if(trace_file_ptr != NULL)
-	HDfprintf(trace_file_ptr, "%s %d %d\n", trace, (int)trace_entry_size, (int)(ret_value != NULL));
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     /* If currently logging, generate a message */
-    if(curr_logging) {
+    {
         herr_t fake_ret_value = (NULL == ret_value) ? FAIL : SUCCEED;
 
-        if(H5AC__write_protect_entry_log_msg(f->shared->cache, (H5AC_info_t *)thing, flags, fake_ret_value) < 0)
-            HDONE_ERROR(H5E_CACHE, H5E_LOGFAIL, NULL, "unable to emit log message")
-    } /* end if */
+        if(f->shared->cache->log_info->logging)
+            if(H5C_log_write_protect_entry_msg(f->shared->cache, (H5AC_info_t *)thing, type->id, flags, fake_ret_value) < 0)
+                HDONE_ERROR(H5E_CACHE, H5E_LOGGING, NULL, "unable to emit log message")
+    }
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5AC_protect() */
@@ -1666,12 +1383,6 @@ done:
 herr_t
 H5AC_resize_entry(void *thing, size_t new_size)
 {
-#if H5AC__TRACE_FILE_ENABLED
-    char          	trace[128] = "";
-    FILE *        	trace_file_ptr = NULL;
-#endif /* H5AC__TRACE_FILE_ENABLED */
-    hbool_t log_enabled;              /* TRUE if logging was set up */
-    hbool_t curr_logging;             /* TRUE if currently logging */
     H5AC_info_t *entry_ptr = NULL;    /* Pointer to the cache entry */
     H5C_t *cache_ptr = NULL;          /* Pointer to the entry's associated metadata cache */
     herr_t ret_value = SUCCEED;       /* Return value */
@@ -1681,25 +1392,10 @@ H5AC_resize_entry(void *thing, size_t new_size)
     /* Sanity check */
     HDassert(thing);
 
-#if H5AC__TRACE_FILE_ENABLED
-    /* For the resize pinned entry call, only the addr, and new_size are
-     * really necessary in the trace file. Write the result to catch
-     * occult errors.
-     */
-    if(NULL != (trace_file_ptr = H5C_get_trace_file_ptr_from_entry(thing)))
-        sprintf(trace, "%s 0x%lx %d", FUNC,
-	        (unsigned long)(((H5C_cache_entry_t *)thing)->addr),
-		(int)new_size);
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     entry_ptr = (H5AC_info_t *)thing;
     cache_ptr = entry_ptr->cache_ptr;
     HDassert(cache_ptr);
 
-    /* Check if log messages are being emitted */
-    if(H5C_get_logging_status(cache_ptr, &log_enabled, &curr_logging) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to get logging status")
-
     /* Resize the entry */
     if(H5C_resize_entry(thing, new_size) < 0)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTRESIZE, FAIL, "can't resize entry")
@@ -1716,15 +1412,10 @@ H5AC_resize_entry(void *thing, size_t new_size)
 #endif /* H5_HAVE_PARALLEL */
 
 done:
-#if H5AC__TRACE_FILE_ENABLED
-    if(trace_file_ptr)
-	HDfprintf(trace_file_ptr, "%s %d\n", trace, (int)ret_value);
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     /* If currently logging, generate a message */
-    if(curr_logging)
-        if(H5AC__write_resize_entry_log_msg(cache_ptr, entry_ptr, new_size, ret_value) < 0)
-            HDONE_ERROR(H5E_CACHE, H5E_LOGFAIL, FAIL, "unable to emit log message")
+    if(cache_ptr->log_info->logging)
+        if(H5C_log_write_resize_entry_msg(cache_ptr, entry_ptr, new_size, ret_value) < 0)
+            HDONE_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5AC_resize_entry() */
@@ -1746,12 +1437,6 @@ done:
 herr_t
 H5AC_unpin_entry(void *thing)
 {
-#if H5AC__TRACE_FILE_ENABLED
-    char                trace[128] = "";
-    FILE *              trace_file_ptr = NULL;
-#endif /* H5AC__TRACE_FILE_ENABLED */
-    hbool_t log_enabled;              /* TRUE if logging was set up */
-    hbool_t curr_logging;             /* TRUE if currently logging */
     H5AC_info_t *entry_ptr = NULL;    /* Pointer to the cache entry */
     H5C_t *cache_ptr = NULL;          /* Pointer to the entry's associated metadata cache */
     herr_t      ret_value = SUCCEED;    /* Return value */
@@ -1761,37 +1446,19 @@ H5AC_unpin_entry(void *thing)
     /* Sanity check */
     HDassert(thing);
 
-#if H5AC__TRACE_FILE_ENABLED
-    /* For the unpin entry call, only the addr is really necessary
-     * in the trace file.  Also write the result to catch occult errors.
-     */
-    if(NULL != (trace_file_ptr = H5C_get_trace_file_ptr_from_entry(thing)))
-        sprintf(trace, "%s 0x%lx", FUNC,
-	        (unsigned long)(((H5C_cache_entry_t *)thing)->addr));
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     entry_ptr = (H5AC_info_t *)thing;
     cache_ptr = entry_ptr->cache_ptr;
     HDassert(cache_ptr);
 
-    /* Check if log messages are being emitted */
-    if(H5C_get_logging_status(cache_ptr, &log_enabled, &curr_logging) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to get logging status")
-
     /* Unpin the entry */
     if(H5C_unpin_entry(thing) < 0)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTUNPIN, FAIL, "can't unpin entry")
 
 done:
-#if H5AC__TRACE_FILE_ENABLED
-    if(trace_file_ptr)
-	HDfprintf(trace_file_ptr, "%s %d\n", trace, (int)ret_value);
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     /* If currently logging, generate a message */
-    if(curr_logging)
-        if(H5AC__write_unpin_entry_log_msg(cache_ptr, entry_ptr, ret_value) < 0)
-            HDONE_ERROR(H5E_CACHE, H5E_LOGFAIL, FAIL, "unable to emit log message")
+    if(cache_ptr->log_info->logging)
+        if(H5C_log_write_unpin_entry_msg(cache_ptr, entry_ptr, ret_value) < 0)
+            HDONE_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5AC_unpin_entry() */
@@ -1812,12 +1479,6 @@ done:
 herr_t
 H5AC_destroy_flush_dependency(void * parent_thing, void * child_thing)
 {
-#if H5AC__TRACE_FILE_ENABLED
-    char                trace[128] = "";
-    FILE *              trace_file_ptr = NULL;
-#endif /* H5AC__TRACE_FILE_ENABLED */
-    hbool_t log_enabled;                /* TRUE if logging was set up */
-    hbool_t curr_logging;               /* TRUE if currently logging */
     H5AC_info_t *entry_ptr = NULL;      /* Pointer to the cache entry */
     H5C_t *cache_ptr = NULL;            /* Pointer to the entry's associated metadata cache */
     herr_t      ret_value = SUCCEED;    /* Return value */
@@ -1828,35 +1489,19 @@ H5AC_destroy_flush_dependency(void * parent_thing, void * child_thing)
     HDassert(parent_thing);
     HDassert(child_thing);
 
-#if H5AC__TRACE_FILE_ENABLED
-    if(NULL != (trace_file_ptr = H5C_get_trace_file_ptr_from_entry(parent_thing)))
-        sprintf(trace, "%s %llx %llx", FUNC,
-	        (unsigned long long)(((H5C_cache_entry_t *)parent_thing)->addr),
-	        (unsigned long long)(((H5C_cache_entry_t *)child_thing)->addr));
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     entry_ptr = (H5AC_info_t *)parent_thing;
     cache_ptr = entry_ptr->cache_ptr;
     HDassert(cache_ptr);
 
-    /* Check if log messages are being emitted */
-    if(H5C_get_logging_status(cache_ptr, &log_enabled, &curr_logging) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to get logging status")
-
     /* Destroy the flush dependency */
     if(H5C_destroy_flush_dependency(parent_thing, child_thing) < 0)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTUNDEPEND, FAIL, "H5C_destroy_flush_dependency() failed")
 
 done:
-#if H5AC__TRACE_FILE_ENABLED
-    if(trace_file_ptr != NULL)
-	HDfprintf(trace_file_ptr, "%s %d\n", trace, (int)ret_value);
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     /* If currently logging, generate a message */
-    if(curr_logging)
-        if(H5AC__write_destroy_fd_log_msg(cache_ptr, (H5AC_info_t *)parent_thing, (H5AC_info_t *)child_thing, ret_value) < 0)
-            HDONE_ERROR(H5E_CACHE, H5E_LOGFAIL, FAIL, "unable to emit log message")
+    if(cache_ptr->log_info->logging)
+        if(H5C_log_write_destroy_fd_msg(cache_ptr, (H5AC_info_t *)parent_thing, (H5AC_info_t *)child_thing, ret_value) < 0)
+            HDONE_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5AC_destroy_flush_dependency() */
@@ -1904,17 +1549,11 @@ herr_t
 H5AC_unprotect(H5F_t *f, const H5AC_class_t *type, haddr_t addr, void *thing,
     unsigned flags)
 {
-#if H5AC__TRACE_FILE_ENABLED
-    char                trace[128] = "";
-    FILE *              trace_file_ptr = NULL;
-#endif /* H5AC__TRACE_FILE_ENABLED */
     hbool_t		dirtied;
     hbool_t		deleted;
 #ifdef H5_HAVE_PARALLEL
     H5AC_aux_t        * aux_ptr = NULL;
 #endif /* H5_HAVE_PARALLEL */
-    hbool_t log_enabled;              /* TRUE if logging was set up */
-    hbool_t curr_logging;             /* TRUE if currently logging */
     herr_t              ret_value=SUCCEED;      /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
@@ -1931,19 +1570,6 @@ H5AC_unprotect(H5F_t *f, const H5AC_class_t *type, haddr_t addr, void *thing,
     HDassert( ((H5AC_info_t *)thing)->addr == addr );
     HDassert( ((H5AC_info_t *)thing)->type == type );
 
-    /* Check if log messages are being emitted */
-    if(H5C_get_logging_status(f->shared->cache, &log_enabled, &curr_logging) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to get logging status")
-
-#if H5AC__TRACE_FILE_ENABLED
-    /* For the unprotect call, only the addr, type id, flags, and possible
-     * new size are really necessary in the trace file.  Write the return
-     * value to catch occult errors.
-     */
-    if(NULL != (trace_file_ptr = H5C_get_trace_file_ptr(cache_ptr)))
-        sprintf(trace, "%s 0x%lx %d", FUNC, (unsigned long)addr, (int)(type->id));
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     dirtied = (hbool_t)(((flags & H5AC__DIRTIED_FLAG) == H5AC__DIRTIED_FLAG) ||
 		(((H5AC_info_t *)thing)->dirtied));
     deleted = (hbool_t)((flags & H5C__DELETED_FLAG) == H5C__DELETED_FLAG);
@@ -1984,15 +1610,10 @@ H5AC_unprotect(H5F_t *f, const H5AC_class_t *type, haddr_t addr, void *thing,
 #endif /* H5_HAVE_PARALLEL */
 
 done:
-#if H5AC__TRACE_FILE_ENABLED
-    if(trace_file_ptr != NULL)
-	HDfprintf(trace_file_ptr, "%s 0x%x %d\n", trace, (unsigned)flags, (int)ret_value);
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     /* If currently logging, generate a message */
-    if(curr_logging)
-        if(H5AC__write_unprotect_entry_log_msg(f->shared->cache, (H5AC_info_t *)thing, type->id, flags, ret_value) < 0)
-            HDONE_ERROR(H5E_CACHE, H5E_LOGFAIL, FAIL, "unable to emit log message")
+    if(f->shared->cache->log_info->logging)
+        if(H5C_log_write_unprotect_entry_msg(f->shared->cache, (H5AC_info_t *)thing, type->id, flags, ret_value) < 0)
+            HDONE_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5AC_unprotect() */
@@ -2191,12 +1812,6 @@ done:
 herr_t
 H5AC_set_cache_auto_resize_config(H5AC_t *cache_ptr, H5AC_cache_config_t *config_ptr)
 {
-#if H5AC__TRACE_FILE_ENABLED
-    H5AC_cache_config_t trace_config = H5AC__DEFAULT_CACHE_CONFIG;
-    FILE *              trace_file_ptr = NULL;
-#endif /* H5AC__TRACE_FILE_ENABLED */
-    hbool_t log_enabled;                /* TRUE if logging was set up */
-    hbool_t curr_logging;               /* TRUE if currently logging */
     H5C_auto_size_ctl_t internal_config;
     herr_t  ret_value = SUCCEED;      	/* Return value */
 
@@ -2205,18 +1820,6 @@ H5AC_set_cache_auto_resize_config(H5AC_t *cache_ptr, H5AC_cache_config_t *config
     /* Sanity checks */
     HDassert(cache_ptr);
 
-    /* Check if log messages are being emitted */
-    if(H5C_get_logging_status(cache_ptr, &log_enabled, &curr_logging) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to get logging status")
-
-#if H5AC__TRACE_FILE_ENABLED
-    /* Make note of the new configuration.  Don't look up the trace file
-     * pointer, as that may change before we use it.
-     */
-    if(config_ptr != NULL)
-        trace_config = *config_ptr;
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     if(cache_ptr == NULL)
         HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "bad cache_ptr on entry")
 #ifdef H5_HAVE_PARALLEL
@@ -2233,23 +1836,25 @@ H5AC_set_cache_auto_resize_config(H5AC_t *cache_ptr, H5AC_cache_config_t *config
     if(H5AC_validate_config(config_ptr) != SUCCEED)
         HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, FAIL, "Bad cache configuration")
 
-    if(config_ptr->open_trace_file) {
-	FILE * file_ptr;
-
-	if(NULL == (file_ptr = H5C_get_trace_file_ptr(cache_ptr)))
-	    HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "H5C_get_trace_file_ptr() failed")
-
-	if((!(config_ptr->close_trace_file)) && (file_ptr != NULL))
-            HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, FAIL, "Trace file already open")
-    } /* end if */
-
-    /* Close & reopen trace file, if requested */
+    /* If the cache config struct is being used to control logging, perform
+     * the open/close operations. Note that this is the only place where the
+     * struct-based control opens and closes the log files so we also have
+     * to write start/stop messages.
+     */
+    /* close */
     if(config_ptr->close_trace_file)
-	if(H5AC__close_trace_file(cache_ptr) < 0)
-            HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "H5AC__close_trace_file() failed")
-    if(config_ptr->open_trace_file)
-        if(H5AC__open_trace_file(cache_ptr, config_ptr->trace_file_name) < 0)
-	    HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, FAIL, "H5AC__open_trace_file() failed")
+        if(H5C_log_tear_down((H5C_t *)cache_ptr) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "mdc logging tear-down failed")
+
+    /* open */
+    if(config_ptr->open_trace_file) {
+        /* Turn on metadata cache logging.
+         * This will be trace output until we create a special API call. JSON
+         * output is generated when logging is controlled by the H5P calls.
+         */
+        if(H5C_log_set_up((H5C_t *)cache_ptr, config_ptr->trace_file_name, H5C_LOG_STYLE_TRACE, TRUE) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "mdc logging setup failed")
+    }
 
     /* Convert external configuration to internal representation */
     if(H5AC__ext_config_2_int_config(config_ptr, &internal_config) < 0)
@@ -2275,52 +1880,10 @@ H5AC_set_cache_auto_resize_config(H5AC_t *cache_ptr, H5AC_cache_config_t *config
 #endif /* H5_HAVE_PARALLEL */
 
 done:
-#if H5AC__TRACE_FILE_ENABLED
-    /* For the set cache auto resize config call, only the contents
-     * of the config is necessary in the trace file. Write the return
-     * value to catch occult errors.
-     */
-    if(NULL != (trace_file_ptr = H5C_get_trace_file_ptr(cache_ptr)))
-	HDfprintf(trace_file_ptr,
-                  "%s %d %d %d %d \"%s\" %d %d %d %f %d %d %ld %d %f %f %d %f %f %d %d %d %f %f %d %d %d %d %f %zu %d %d\n",
-		  "H5AC_set_cache_auto_resize_config",
-		  trace_config.version,
-		  (int)(trace_config.rpt_fcn_enabled),
-		  (int)(trace_config.open_trace_file),
-		  (int)(trace_config.close_trace_file),
-		  trace_config.trace_file_name,
-		  (int)(trace_config.evictions_enabled),
-		  (int)(trace_config.set_initial_size),
-		  (int)(trace_config.initial_size),
-		  trace_config.min_clean_fraction,
-		  (int)(trace_config.max_size),
-		  (int)(trace_config.min_size),
-		  trace_config.epoch_length,
-		  (int)(trace_config.incr_mode),
-		  trace_config.lower_hr_threshold,
-		  trace_config.increment,
-		  (int)(trace_config.flash_incr_mode),
-		  trace_config.flash_multiple,
-		  trace_config.flash_threshold,
-		  (int)(trace_config.apply_max_increment),
-		  (int)(trace_config.max_increment),
-		  (int)(trace_config.decr_mode),
-		  trace_config.upper_hr_threshold,
-		  trace_config.decrement,
-		  (int)(trace_config.apply_max_decrement),
-		  (int)(trace_config.max_decrement),
-		  trace_config.epochs_before_eviction,
-		  (int)(trace_config.apply_empty_reserve),
-		  trace_config.empty_reserve,
-		  trace_config.dirty_bytes_threshold,
-		  trace_config.metadata_write_strategy,
-		  (int)ret_value);
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     /* If currently logging, generate a message */
-    if(curr_logging)
-        if(H5AC__write_set_cache_config_log_msg(cache_ptr, config_ptr, ret_value) < 0)
-            HDONE_ERROR(H5E_CACHE, H5E_LOGFAIL, FAIL, "unable to emit log message")
+    if(cache_ptr->log_info->logging)
+        if(H5C_log_write_set_cache_config_msg(cache_ptr, config_ptr, ret_value) < 0)
+            HDONE_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5AC_set_cache_auto_resize_config() */
@@ -2366,12 +1929,12 @@ H5AC_validate_config(H5AC_cache_config_t *config_ptr)
     if(config_ptr->open_trace_file) {
         size_t	        name_len;
 
-	/* Can't really test the trace_file_name field without trying to
-	 * open the file, so we will content ourselves with a couple of
-	 * sanity checks on the length of the file name.
-	 */
-	name_len = HDstrlen(config_ptr->trace_file_name);
-	if(name_len == 0)
+        /* Can't really test the trace_file_name field without trying to
+         * open the file, so we will content ourselves with a couple of
+         * sanity checks on the length of the file name.
+         */
+        name_len = HDstrlen(config_ptr->trace_file_name);
+        if(name_len == 0)
             HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, FAIL, "config_ptr->trace_file_name is empty")
         else if(name_len > H5AC__MAX_TRACE_FILE_NAME_LEN)
             HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, FAIL, "config_ptr->trace_file_name too long")
@@ -3062,12 +2625,6 @@ H5AC_remove_entry(void *_entry)
 {
     H5AC_info_t *entry = (H5AC_info_t *)_entry; /* Entry to remove */
     H5C_t *cache = NULL;                /* Pointer to the entry's associated metadata cache */
-#if H5AC__TRACE_FILE_ENABLED
-    char                trace[128] = "";
-    FILE *              trace_file_ptr = NULL;
-#endif /* H5AC__TRACE_FILE_ENABLED */
-    hbool_t log_enabled;                /* TRUE if logging was set up */
-    hbool_t curr_logging;               /* TRUE if currently logging */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
@@ -3077,32 +2634,15 @@ H5AC_remove_entry(void *_entry)
     cache = entry->cache_ptr;
     HDassert(cache);
 
-#if H5AC__TRACE_FILE_ENABLED
-    /* For the remove entry call, only the addr is really necessary
-     * in the trace file.  Also write the result to catch occult errors.
-     */
-    if(NULL != (trace_file_ptr = H5C_get_trace_file_ptr_from_entry(entry)))
-        sprintf(trace, "%s 0x%lx", FUNC, (unsigned long)(entry->addr));
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
-    /* Check if log messages are being emitted */
-    if(H5C_get_logging_status(cache, &log_enabled, &curr_logging) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_CANTGET, FAIL, "unable to get logging status")
-
     /* Remove the entry from the cache*/
     if(H5C_remove_entry(entry) < 0)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTREMOVE, FAIL, "can't remove entry")
 
 done:
-#if H5AC__TRACE_FILE_ENABLED
-    if(trace_file_ptr)
-	HDfprintf(trace_file_ptr, "%s %d\n", trace, (int)ret_value);
-#endif /* H5AC__TRACE_FILE_ENABLED */
-
     /* If currently logging, generate a message */
-    if(curr_logging)
-        if(H5AC__write_remove_entry_log_msg(cache, entry, ret_value) < 0)
-            HDONE_ERROR(H5E_CACHE, H5E_LOGFAIL, FAIL, "unable to emit log message")
+    if(cache->log_info->logging)
+        if(H5C_log_write_remove_entry_msg(cache, entry, ret_value) < 0)
+            HDONE_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5AC_remove_entry() */
diff --git a/src/H5ACdbg.c b/src/H5ACdbg.c
index c6d71a8..1235206 100644
--- a/src/H5ACdbg.c
+++ b/src/H5ACdbg.c
@@ -136,121 +136,6 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5AC__close_trace_file()
- *
- * Purpose:     If a trace file is open, stop logging calls to the cache,
- *              and close the file.
- *
- *              Note that the function does nothing if there is no trace
- *              file.
- *
- * Return:      Non-negative on success/Negative on failure
- *
- * Programmer:  John Mainzer
- *              6/2/06
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5AC__close_trace_file(H5AC_t *cache_ptr)
-{
-    FILE *   trace_file_ptr;
-    herr_t   ret_value = SUCCEED;    /* Return value */
-
-    FUNC_ENTER_PACKAGE
-
-    if(cache_ptr == NULL)
-        HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, FAIL, "NULL cache_ptr on entry.")
-
-    if(NULL == (trace_file_ptr = H5C_get_trace_file_ptr(cache_ptr)))
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "H5C_get_trace_file_ptr() failed.")
-
-    if(trace_file_ptr != NULL) {
-        if(H5C_set_trace_file_ptr(cache_ptr, NULL) < 0)
-            HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "H5C_set_trace_file_ptr() failed.")
-
-        if(HDfclose(trace_file_ptr) != 0)
-            HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "can't close metadata cache trace file")
-    } /* end if */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5AC__close_trace_file() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5AC__open_trace_file()
- *
- * Purpose:     Open a trace file, and start logging calls to the cache.
- *
- * 		This logging is done at the H5C level, and will only take
- * 		place if H5C_TRACE_FILE_ENABLED (defined in H5Cprivate.h)
- * 		is TRUE.
- *
- * Return:      Non-negative on success/Negative on failure
- *
- * Programmer:  John Mainzer
- *              6/1/06
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5AC__open_trace_file(H5AC_t *cache_ptr, const char *trace_file_name)
-{
-    char     file_name[H5AC__MAX_TRACE_FILE_NAME_LEN + H5C__PREFIX_LEN + 2];
-    FILE *   file_ptr;
-    herr_t   ret_value = SUCCEED;    /* Return value */
-
-    FUNC_ENTER_PACKAGE
-
-    HDassert(cache_ptr);
-
-    /* Check args */
-    if(cache_ptr == NULL)
-        HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, FAIL, "cache_ptr NULL on entry.")
-    if(trace_file_name == NULL)
-        HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, FAIL, "NULL trace_file_name on entry.")
-    if(HDstrlen(trace_file_name) > H5AC__MAX_TRACE_FILE_NAME_LEN)
-        HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, FAIL, "trace file name too long.")
-    if(NULL != (file_ptr = H5C_get_trace_file_ptr(cache_ptr)))
-        HGOTO_ERROR(H5E_CACHE, H5E_FILEOPEN, FAIL, "trace file already open.")
-
-#ifdef H5_HAVE_PARALLEL
-{
-    H5AC_aux_t * aux_ptr;
-
-    aux_ptr = (H5AC_aux_t *)H5C_get_aux_ptr(cache_ptr);
-    if(aux_ptr == NULL)
-        sprintf(file_name, "%s", trace_file_name);
-    else {
-	if(aux_ptr->magic != H5AC__H5AC_AUX_T_MAGIC)
-            HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "Bad aux_ptr->magic.")
-
-        sprintf(file_name, "%s.%d", trace_file_name, aux_ptr->mpi_rank);
-    } /* end else */
-
-    if(HDstrlen(file_name) > H5AC__MAX_TRACE_FILE_NAME_LEN + H5C__PREFIX_LEN + 1)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "cooked trace file name too long.")
-}
-#else /* H5_HAVE_PARALLEL */
-    HDsnprintf(file_name, (size_t)(H5AC__MAX_TRACE_FILE_NAME_LEN + H5C__PREFIX_LEN + 1), 
-               "%s", trace_file_name);
-#endif /* H5_HAVE_PARALLEL */
-
-    if((file_ptr = HDfopen(file_name, "w")) == NULL)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "trace file open failed.")
-
-    HDfprintf(file_ptr, "### HDF5 metadata cache trace file version 1 ###\n");
-
-    if(H5C_set_trace_file_ptr(cache_ptr, file_ptr) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "H5C_set_trace_file_ptr() failed.")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5AC__open_trace_file() */
-
-
-/*-------------------------------------------------------------------------
  *
  * Function:    H5AC_get_entry_ptr_from_addr()
  *
diff --git a/src/H5AClog.c b/src/H5AClog.c
deleted file mode 100644
index 51a2050..0000000
--- a/src/H5AClog.c
+++ /dev/null
@@ -1,1105 +0,0 @@
-/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
- * Copyright by The HDF Group.                                               *
- * Copyright by the Board of Trustees of the University of Illinois.         *
- * All rights reserved.                                                      *
- *                                                                           *
- * This file is part of HDF5.  The full HDF5 copyright notice, including     *
- * terms governing use, modification, and redistribution, is contained in    *
- * the COPYING file, which can be found at the root of the source code       *
- * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
- * If you do not have access to either file, you may request a copy from     *
- * help@hdfgroup.org.                                                        *
- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
-
-/*-------------------------------------------------------------------------
- *
- * Created:             H5AClog.c
- *
- * Purpose:             Functions for metadata cache logging in JSON format
- *
- *-------------------------------------------------------------------------
- */
-
-/****************/
-/* Module Setup */
-/****************/
-#include "H5ACmodule.h"         /* This source code file is part of the H5AC module */
-
-/***********/
-/* Headers */
-/***********/
-#include "H5private.h"          /* Generic Functions                    */
-#include "H5ACpkg.h"            /* Metadata cache                       */
-#include "H5Cprivate.h"		/* Cache                                */
-#include "H5Eprivate.h"         /* Error handling                       */
-
-
-/****************/
-/* Local Macros */
-/****************/
-
-#define MSG_SIZE 128
-
-
-/******************/
-/* Local Typedefs */
-/******************/
-
-
-/********************/
-/* Package Typedefs */
-/********************/
-
-
-/********************/
-/* Local Prototypes */
-/********************/
-
-
-/*********************/
-/* Package Variables */
-/*********************/
-
-
-/*****************************/
-/* Library Private Variables */
-/*****************************/
-
-
-/*******************/
-/* Local Variables */
-/*******************/
-
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5AC__write_create_cache_log_msg
- *
- * Purpose:     Write a log message for cache creation.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:	Dana Robinson
- *              Sunday, March 16, 2014
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5AC__write_create_cache_log_msg(H5AC_t *cache) 
-{
-    char msg[MSG_SIZE];
-    hbool_t log_enabled;                /* TRUE if logging was set up */
-    hbool_t curr_logging;               /* TRUE if currently logging */
-    herr_t ret_value = SUCCEED;         /* Return value */
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Sanity checks */
-    HDassert(cache);
-
-    /* Check if log messages are being emitted */
-    if(H5C_get_logging_status(cache, &log_enabled, &curr_logging) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to get logging status")
-
-    /* Since we're about to override the current logging flag,
-     * check the "log enabled" flag to see if we didn't get here
-     * by mistake.
-     */
-    if(!log_enabled)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "attempt to write opening log message when logging is disabled")
-
-    /* Create the log message string */
-    HDsnprintf(msg, MSG_SIZE, 
-"\
-{\n\
-\"create_time\":%lld,\n\
-\"messages\":\n\
-[\n\
-"
-    , (long long)HDtime(NULL));
-
-    /* Have to temporarily enable logging, if it isn't currently  */
-    if(!curr_logging)
-        if(H5C_start_logging(cache) < 0)
-            HGOTO_ERROR(H5E_CACHE, H5E_LOGFAIL, FAIL, "unable to start mdc logging")
-
-    /* Write the log message to the file */
-    if(H5C_write_log_message(cache, msg) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to emit log message")
-
-    /* Stop logging, if it wasn't started originally */
-    if(!curr_logging)
-        if(H5C_stop_logging(cache) < 0)
-            HGOTO_ERROR(H5E_CACHE, H5E_LOGFAIL, FAIL, "unable to stop mdc logging")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5AC__write_create_cache_log_msg() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5AC__write_destroy_cache_log_msg
- *
- * Purpose:     Write a log message for cache destruction.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:	Dana Robinson
- *              Sunday, March 16, 2014
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5AC__write_destroy_cache_log_msg(H5AC_t *cache)
-{
-    char msg[MSG_SIZE];
-    hbool_t log_enabled;                /* TRUE if logging was set up */
-    hbool_t curr_logging;               /* TRUE if currently logging */
-    herr_t ret_value = SUCCEED;         /* Return value */
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Sanity checks */
-    HDassert(cache);
-
-    /* Check if log messages are being emitted */
-    if(H5C_get_logging_status(cache, &log_enabled, &curr_logging) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to get logging status")
-
-    /* Since we're about to override the current logging flag,
-     * check the "log enabled" flag to see if we didn't get here
-     * by mistake.
-     */
-    if(!log_enabled)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "attempt to write closing log message when logging is disabled")
-
-    /* Create the log message string */
-    HDsnprintf(msg, MSG_SIZE, 
-"\
-],\n\
-\"close_time\":%lld,\n\
-}\n\
-"
-    , (long long)HDtime(NULL));
-
-    /* Have to temporarily enable logging, if it isn't currently  */
-    if(!curr_logging)
-        if(H5C_start_logging(cache) < 0)
-            HGOTO_ERROR(H5E_CACHE, H5E_LOGFAIL, FAIL, "unable to start mdc logging")
-
-    /* Write the log message to the file */
-    if(H5C_write_log_message(cache, msg) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to emit log message")
-
-    /* Stop logging, if it wasn't started originally */
-    if(!curr_logging)
-        if(H5C_stop_logging(cache) < 0)
-            HGOTO_ERROR(H5E_CACHE, H5E_LOGFAIL, FAIL, "unable to stop mdc logging")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5AC__write_destroy_cache_log_msg() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5AC__write_evict_cache_log_msg
- *
- * Purpose:     Write a log message for eviction of cache entries.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:	Dana Robinson
- *              Sunday, March 16, 2014
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5AC__write_evict_cache_log_msg(const H5AC_t *cache,
-                                herr_t fxn_ret_value)
-{
-    char msg[MSG_SIZE];
-    herr_t ret_value = SUCCEED;
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Sanity checks */
-    HDassert(cache);
-
-    /* Create the log message string */
-    HDsnprintf(msg, MSG_SIZE, 
-"\
-{\
-\"timestamp\":%lld,\
-\"action\":\"evict\",\
-\"returned\":%d\
-},\n\
-"
-    , (long long)HDtime(NULL), (int)fxn_ret_value);
-
-    /* Write the log message to the file */
-    if(H5C_write_log_message(cache, msg) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to emit log message")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5AC__write_evict_cache_log_msg() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5AC__write_expunge_entry_log_msg
- *
- * Purpose:     Write a log message for expunge of cache entries.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:	Dana Robinson
- *              Sunday, March 16, 2014
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5AC__write_expunge_entry_log_msg(const H5AC_t *cache,
-                                  haddr_t address,
-                                  int type_id,
-                                  herr_t fxn_ret_value)
-{
-    char msg[MSG_SIZE];
-    herr_t ret_value = SUCCEED;
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Sanity checks */
-    HDassert(cache);
-
-    /* Create the log message string */
-    HDsnprintf(msg, MSG_SIZE, 
-"\
-{\
-\"timestamp\":%lld,\
-\"action\":\"expunge\",\
-\"address\":0x%lx,\
-\"type_id\":%d,\
-\"returned\":%d\
-},\n\
-"
-    , (long long)HDtime(NULL), (unsigned long)address, (int)type_id, (int)fxn_ret_value);
-
-
-    /* Write the log message to the file */
-    if(H5C_write_log_message(cache, msg) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to emit log message")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5AC__write_expunge_entry_log_msg() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5AC__write_flush_cache_log_msg
- *
- * Purpose:     Write a log message for cache flushes.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:	Dana Robinson
- *              Sunday, March 16, 2014
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5AC__write_flush_cache_log_msg(const H5AC_t *cache,
-                                herr_t fxn_ret_value)
-{
-    char msg[MSG_SIZE];
-    herr_t ret_value = SUCCEED;
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Sanity checks */
-    HDassert(cache);
-
-    /* Create the log message string */
-    HDsnprintf(msg, MSG_SIZE, 
-"\
-{\
-\"timestamp\":%lld,\
-\"action\":\"flush\",\
-\"returned\":%d\
-},\n\
-"
-    , (long long)HDtime(NULL), (int)fxn_ret_value);
-
-    /* Write the log message to the file */
-    if(H5C_write_log_message(cache, msg) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to emit log message")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5AC__write_flush_cache_log_msg() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5AC__write_insert_entry_log_msg
- *
- * Purpose:     Write a log message for insertion of cache entries.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:	Dana Robinson
- *              Sunday, March 16, 2014
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5AC__write_insert_entry_log_msg(const H5AC_t *cache,
-                                 haddr_t address,
-                                 int type_id,
-                                 unsigned flags,
-                                 size_t size,
-                                 herr_t fxn_ret_value)
-{
-    char msg[MSG_SIZE];
-    herr_t ret_value = SUCCEED;
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Sanity checks */
-    HDassert(cache);
-
-
-    /* Create the log message string */
-    HDsnprintf(msg, MSG_SIZE, 
-"\
-{\
-\"timestamp\":%lld,\
-\"action\":\"insert\",\
-\"address\":0x%lx,\
-\"flags\":0x%x,\
-\"type_id\":%d,\
-\"size\":%d,\
-\"returned\":%d\
-},\n\
-"
-    , (long long)HDtime(NULL), (unsigned long)address, flags, type_id, 
-      (int)size, (int)fxn_ret_value);
-
-    /* Write the log message to the file */
-    if(H5C_write_log_message(cache, msg) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to emit log message")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5AC__write_insert_entry_log_msg() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5AC__write_mark_dirty_entry_log_msg
- *
- * Purpose:     Write a log message for marking cache entries as dirty.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:	Dana Robinson
- *              Sunday, March 16, 2014
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5AC__write_mark_dirty_entry_log_msg(const H5AC_t *cache,
-                                     const H5AC_info_t *entry,
-                                     herr_t fxn_ret_value)
-{
-    char msg[MSG_SIZE];
-    herr_t ret_value = SUCCEED;
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Sanity checks */
-    HDassert(cache);
-    HDassert(entry);
-
-    /* Create the log message string */
-    HDsnprintf(msg, MSG_SIZE, 
-"\
-{\
-\"timestamp\":%lld,\
-\"action\":\"dirty\",\
-\"address\":0x%lx,\
-\"returned\":%d\
-},\n\
-"
-    , (long long)HDtime(NULL), (unsigned long)entry->addr, (int)fxn_ret_value);
-
-    /* Write the log message to the file */
-    if(H5C_write_log_message(cache, msg) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to emit log message")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5AC__write_mark_dirty_entry_log_msg() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5AC__write_mark_clean_entry_log_msg
- *
- * Purpose:     Write a log message for marking cache entries as clean.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:	Quincey Koziol
- *              Saturday, July 23, 2016
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5AC__write_mark_clean_entry_log_msg(const H5AC_t *cache, const H5AC_info_t *entry,
-    herr_t fxn_ret_value)
-{
-    char msg[MSG_SIZE];                 /* Log message buffer */
-    herr_t ret_value = SUCCEED;         /* Return value */
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Sanity checks */
-    HDassert(cache);
-    HDassert(entry);
-
-    /* Create the log message string */
-    HDsnprintf(msg, MSG_SIZE, 
-"\
-{\
-\"timestamp\":%lld,\
-\"action\":\"clean\",\
-\"address\":0x%lx,\
-\"returned\":%d\
-},\n\
-"
-    , (long long)HDtime(NULL), (unsigned long)entry->addr, (int)fxn_ret_value);
-
-    /* Write the log message to the file */
-    if(H5C_write_log_message(cache, msg) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to emit log message")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5AC__write_mark_clean_entry_log_msg() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5AC__write_mark_unserialized_entry_log_msg
- *
- * Purpose:     Write a log message for marking cache entries as unserialized.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:	Quincey Koziol
- *              Thursday, December 22, 2016
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5AC__write_mark_unserialized_entry_log_msg(const H5AC_t *cache,
-                                     const H5AC_info_t *entry,
-                                     herr_t fxn_ret_value)
-{
-    char msg[MSG_SIZE];
-    herr_t ret_value = SUCCEED;
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Sanity checks */
-    HDassert(cache);
-    HDassert(entry);
-
-    /* Create the log message string */
-    HDsnprintf(msg, MSG_SIZE, 
-"\
-{\
-\"timestamp\":%lld,\
-\"action\":\"unserialized\",\
-\"address\":0x%lx,\
-\"returned\":%d\
-},\n\
-"
-    , (long long)HDtime(NULL), (unsigned long)entry->addr, (int)fxn_ret_value);
-
-    /* Write the log message to the file */
-    if(H5C_write_log_message(cache, msg) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to emit log message")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5AC__write_mark_unserialized_entry_log_msg() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5AC__write_mark_serialize_entry_log_msg
- *
- * Purpose:     Write a log message for marking cache entries as serialize.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:	Quincey Koziol
- *              Thursday, December 22, 2016
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5AC__write_mark_serialized_entry_log_msg(const H5AC_t *cache, const H5AC_info_t *entry,
-    herr_t fxn_ret_value)
-{
-    char msg[MSG_SIZE];                 /* Log message buffer */
-    herr_t ret_value = SUCCEED;         /* Return value */
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Sanity checks */
-    HDassert(cache);
-    HDassert(entry);
-
-    /* Create the log message string */
-    HDsnprintf(msg, MSG_SIZE, 
-"\
-{\
-\"timestamp\":%lld,\
-\"action\":\"serialized\",\
-\"address\":0x%lx,\
-\"returned\":%d\
-},\n\
-"
-    , (long long)HDtime(NULL), (unsigned long)entry->addr, (int)fxn_ret_value);
-
-    /* Write the log message to the file */
-    if(H5C_write_log_message(cache, msg) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to emit log message")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5AC__write_mark_serialized_entry_log_msg() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5AC__write_move_entry_log_msg
- *
- * Purpose:     Write a log message for moving a cache entry.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:	Dana Robinson
- *              Sunday, March 16, 2014
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5AC__write_move_entry_log_msg(const H5AC_t *cache,
-                               haddr_t old_addr,
-                               haddr_t new_addr,
-                               int type_id,
-                               herr_t fxn_ret_value)
-{
-    char msg[MSG_SIZE];
-    herr_t ret_value = SUCCEED;
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Sanity checks */
-    HDassert(cache);
-
-    /* Create the log message string */
-    HDsnprintf(msg, MSG_SIZE, 
-"\
-{\
-\"timestamp\":%lld,\
-\"action\":\"move\",\
-\"old_address\":0x%lx,\
-\"new_address\":0x%lx,\
-\"type_id\":%d,\
-\"returned\":%d\
-},\n\
-"
-    , (long long)HDtime(NULL), (unsigned long)old_addr, 
-      (unsigned long)new_addr, type_id, (int)fxn_ret_value);
-
-    /* Write the log message to the file */
-    if(H5C_write_log_message(cache, msg) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to emit log message")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5AC__write_move_entry_log_msg() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5AC__write_pin_entry_log_msg
- *
- * Purpose:     Write a log message for pinning a cache entry.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:	Dana Robinson
- *              Sunday, March 16, 2014
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5AC__write_pin_entry_log_msg(const H5AC_t *cache,
-                              const H5AC_info_t *entry,
-                              herr_t fxn_ret_value)
-{
-    char msg[MSG_SIZE];
-    herr_t ret_value = SUCCEED;
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Sanity checks */
-    HDassert(cache);
-    HDassert(entry);
-
-    /* Create the log message string */
-    HDsnprintf(msg, MSG_SIZE, 
-"\
-{\
-\"timestamp\":%lld,\
-\"action\":\"pin\",\
-\"address\":0x%lx,\
-\"returned\":%d\
-},\n\
-"
-    , (long long)HDtime(NULL), (unsigned long)entry->addr, 
-      (int)fxn_ret_value);
-
-    /* Write the log message to the file */
-    if(H5C_write_log_message(cache, msg) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to emit log message")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5AC__write_pin_entry_log_msg() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5AC__write_create_fd_log_msg
- *
- * Purpose:     Write a log message for creating a flush dependency between
- *              two cache entries.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:	Dana Robinson
- *              Sunday, March 16, 2014
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5AC__write_create_fd_log_msg(const H5AC_t *cache,
-                              const H5AC_info_t *parent,
-                              const H5AC_info_t *child,
-                              herr_t fxn_ret_value)
-{
-    char msg[MSG_SIZE];
-    herr_t ret_value = SUCCEED;
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Sanity checks */
-    HDassert(cache);
-    HDassert(parent);
-    HDassert(child);
-
-    /* Create the log message string */
-    HDsnprintf(msg, MSG_SIZE, 
-"\
-{\
-\"timestamp\":%lld,\
-\"action\":\"create_fd\",\
-\"parent_addr\":0x%lx,\
-\"child_addr\":0x%lx,\
-\"returned\":%d\
-},\n\
-"
-    , (long long)HDtime(NULL), (unsigned long)parent->addr, 
-      (unsigned long)child->addr, (int)fxn_ret_value);
-
-    /* Write the log message to the file */
-    if(H5C_write_log_message(cache, msg) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to emit log message")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5AC__write_create_fd_log_msg() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5AC__write_protect_entry_log_msg
- *
- * Purpose:     Write a log message for protecting a cache entry.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:	Dana Robinson
- *              Sunday, March 16, 2014
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5AC__write_protect_entry_log_msg(const H5AC_t *cache,
-                                  const H5AC_info_t *entry,
-                                  unsigned flags,
-                                  herr_t fxn_ret_value)
-{
-    char msg[MSG_SIZE];
-    char rw_s[16];
-    herr_t ret_value = SUCCEED;
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Sanity checks */
-    HDassert(cache);
-    HDassert(entry);
-
-    if(H5AC__READ_ONLY_FLAG == flags)
-        HDstrcpy(rw_s, "READ");
-    else 
-        HDstrcpy(rw_s, "WRITE");
-
-    /* Create the log message string */
-    HDsnprintf(msg, MSG_SIZE, 
-"\
-{\
-\"timestamp\":%lld,\
-\"action\":\"protect\",\
-\"address\":0x%lx,\
-\"readwrite\":\"%s\",\
-\"size\":%d,\
-\"returned\":%d\
-},\n\
-"
-    , (long long)HDtime(NULL), (unsigned long)entry->addr, 
-      rw_s, (int)entry->size, (int)fxn_ret_value);
-
-    /* Write the log message to the file */
-    if(H5C_write_log_message(cache, msg) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to emit log message")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5AC__write_protect_entry_log_msg() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5AC__write_resize_entry_log_msg
- *
- * Purpose:     Write a log message for resizing a cache entry.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:	Dana Robinson
- *              Sunday, March 16, 2014
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5AC__write_resize_entry_log_msg(const H5AC_t *cache,
-                                 const H5AC_info_t *entry,
-                                 size_t new_size,
-                                 herr_t fxn_ret_value)
-{
-    char msg[MSG_SIZE];
-    herr_t ret_value = SUCCEED;
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Sanity checks */
-    HDassert(cache);
-    HDassert(entry);
-
-    /* Create the log message string */
-    HDsnprintf(msg, MSG_SIZE, 
-"\
-{\
-\"timestamp\":%lld,\
-\"action\":\"resize\",\
-\"address\":0x%lx,\
-\"new_size\":%d,\
-\"returned\":%d\
-},\n\
-"
-    , (long long)HDtime(NULL), (unsigned long)entry->addr, 
-      (int)new_size, (int)fxn_ret_value);
-
-    /* Write the log message to the file */
-    if(H5C_write_log_message(cache, msg) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to emit log message")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5AC__write_resize_entry_log_msg() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5AC__write_unpin_entry_log_msg
- *
- * Purpose:     Write a log message for unpinning a cache entry.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:	Dana Robinson
- *              Sunday, March 16, 2014
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5AC__write_unpin_entry_log_msg(const H5AC_t *cache,
-                                const H5AC_info_t *entry,
-                                herr_t fxn_ret_value)
-{
-    char msg[MSG_SIZE];
-    herr_t ret_value = SUCCEED;
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Sanity checks */
-    HDassert(cache);
-    HDassert(entry);
-
-    /* Create the log message string */
-    HDsnprintf(msg, MSG_SIZE, 
-"\
-{\
-\"timestamp\":%lld,\
-\"action\":\"unpin\",\
-\"address\":0x%lx,\
-\"returned\":%d\
-},\n\
-"
-    , (long long)HDtime(NULL), (unsigned long)entry->addr, 
-      (int)fxn_ret_value);
-
-    /* Write the log message to the file */
-    if(H5C_write_log_message(cache, msg) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to emit log message")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5AC__write_unpin_entry_log_msg() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5AC__write_destroy_fd_log_msg
- *
- * Purpose:     Write a log message for destroying a flush dependency
- *              between two cache entries.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:	Dana Robinson
- *              Sunday, March 16, 2014
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5AC__write_destroy_fd_log_msg(const H5AC_t *cache,
-                               const H5AC_info_t *parent,
-                               const H5AC_info_t *child,
-                               herr_t fxn_ret_value)
-{
-    char msg[MSG_SIZE];
-    herr_t ret_value = SUCCEED;
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Sanity checks */
-    HDassert(cache);
-    HDassert(parent);
-    HDassert(child);
-
-    /* Create the log message string */
-    HDsnprintf(msg, MSG_SIZE, 
-"\
-{\
-\"timestamp\":%lld,\
-\"action\":\"destroy_fd\",\
-\"parent_addr\":0x%lx,\
-\"child_addr\":0x%lx,\
-\"returned\":%d\
-},\n\
-"
-    , (long long)HDtime(NULL), (unsigned long)parent->addr, 
-      (unsigned long)child->addr, (int)fxn_ret_value);
-
-    /* Write the log message to the file */
-    if(H5C_write_log_message(cache, msg) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to emit log message")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5AC__write_destroy_fd_log_msg() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5AC__write_unprotect_entry_log_msg
- *
- * Purpose:     Write a log message for unprotecting a cache entry.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:	Dana Robinson
- *              Sunday, March 16, 2014
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5AC__write_unprotect_entry_log_msg(const H5AC_t *cache,
-                                    const H5AC_info_t *entry,
-                                    int type_id,
-                                    unsigned flags,
-                                    herr_t fxn_ret_value)
-{
-    char msg[MSG_SIZE];
-    herr_t ret_value = SUCCEED;
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Sanity checks */
-    HDassert(cache);
-    HDassert(entry);
-
-    /* Create the log message string */
-    HDsnprintf(msg, MSG_SIZE, 
-"\
-{\
-\"timestamp\":%lld,\
-\"action\":\"unprotect\",\
-\"address\":0x%lx,\
-\"id\":%d,\
-\"flags\":%x,\
-\"returned\":%d\
-},\n\
-"
-    , (long long)HDtime(NULL), (unsigned long)entry->addr, 
-      type_id, flags, (int)fxn_ret_value);
-
-    HDsnprintf(msg, MSG_SIZE, " ");
-
-    /* Write the log message to the file */
-    if(H5C_write_log_message(cache, msg) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to emit log message")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5AC__write_unprotect_entry_log_msg() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5AC__write_set_cache_config_log_msg
- *
- * Purpose:     Write a log message for setting the cache configuration.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:	Dana Robinson
- *              Sunday, March 16, 2014
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5AC__write_set_cache_config_log_msg(const H5AC_t *cache,
-                                     const H5AC_cache_config_t *config,
-                                     herr_t fxn_ret_value)
-{
-    char msg[MSG_SIZE];
-    herr_t ret_value = SUCCEED;
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Sanity checks */
-    HDassert(cache);
-    HDassert(config);
-
-    /* Create the log message string */
-    HDsnprintf(msg, MSG_SIZE, 
-"\
-{\
-\"timestamp\":%lld,\
-\"action\":\"set_config\",\
-\"returned\":%d\
-},\n\
-"
-    , (long long)HDtime(NULL), (int)fxn_ret_value);
-
-
-    /* Write the log message to the file */
-    if(H5C_write_log_message(cache, msg) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to emit log message")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5AC__write_set_cache_config_log_msg() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5AC__write_remove_entry_log_msg
- *
- * Purpose:     Write a log message for removing a cache entry.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:  Quincey Koziol
- *              September 17, 2016
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5AC__write_remove_entry_log_msg(const H5AC_t *cache, const H5AC_info_t *entry,
-    herr_t fxn_ret_value)
-{
-    char msg[MSG_SIZE];
-    herr_t ret_value = SUCCEED;
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* Sanity checks */
-    HDassert(cache);
-    HDassert(entry);
-
-    /* Create the log message string */
-    HDsnprintf(msg, MSG_SIZE, 
-"\
-{\
-\"timestamp\":%lld,\
-\"action\":\"remove\",\
-\"address\":0x%lx,\
-\"returned\":%d\
-},\n\
-"
-    , (long long)HDtime(NULL), (unsigned long)entry->addr, 
-      (int)fxn_ret_value);
-
-    /* Write the log message to the file */
-    if(H5C_write_log_message(cache, msg) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unable to emit log message")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5AC__write_remove_entry_log_msg() */
-
diff --git a/src/H5ACpkg.h b/src/H5ACpkg.h
index 9bf84bf..8997382 100644
--- a/src/H5ACpkg.h
+++ b/src/H5ACpkg.h
@@ -433,74 +433,5 @@ H5_DLL herr_t H5AC__set_write_done_callback(H5C_t * cache_ptr,
     void (* write_done)(void));
 #endif /* H5_HAVE_PARALLEL */
 
-/* Trace file routines */
-H5_DLL herr_t H5AC__close_trace_file(H5AC_t *cache_ptr);
-H5_DLL herr_t H5AC__open_trace_file(H5AC_t *cache_ptr, const char *trace_file_name);
-
-/* Cache logging routines */
-H5_DLL herr_t H5AC__write_create_cache_log_msg(H5AC_t *cache);
-H5_DLL herr_t H5AC__write_destroy_cache_log_msg(H5AC_t *cache);
-H5_DLL herr_t H5AC__write_evict_cache_log_msg(const H5AC_t *cache,
-                                        herr_t fxn_ret_value);
-H5_DLL herr_t H5AC__write_expunge_entry_log_msg(const H5AC_t *cache,
-                                                haddr_t address,
-                                                int type_id,
-                                                herr_t fxn_ret_value);
-H5_DLL herr_t H5AC__write_flush_cache_log_msg(const H5AC_t *cache,
-                                              herr_t fxn_ret_value);
-H5_DLL herr_t H5AC__write_insert_entry_log_msg(const H5AC_t *cache,
-                                               haddr_t address,
-                                               int type_id,
-                                               unsigned flags,
-                                               size_t size,
-                                               herr_t fxn_ret_value);
-H5_DLL herr_t H5AC__write_mark_dirty_entry_log_msg(const H5AC_t *cache,
-                                                   const H5AC_info_t *entry,
-                                                   herr_t fxn_ret_value);
-H5_DLL herr_t H5AC__write_mark_clean_entry_log_msg(const H5AC_t *cache,
-    const H5AC_info_t *entry, herr_t fxn_ret_value);
-H5_DLL herr_t H5AC__write_mark_unserialized_entry_log_msg(const H5AC_t *cache,
-        const H5AC_info_t *entry, herr_t fxn_ret_value);
-H5_DLL herr_t H5AC__write_mark_serialized_entry_log_msg(const H5AC_t *cache,
-    const H5AC_info_t *entry, herr_t fxn_ret_value);
-H5_DLL herr_t H5AC__write_move_entry_log_msg(const H5AC_t *cache,
-                                             haddr_t old_addr,
-                                             haddr_t new_addr,
-                                             int type_id,
-                                             herr_t fxn_ret_value);
-H5_DLL herr_t H5AC__write_pin_entry_log_msg(const H5AC_t *cache,
-                                            const H5AC_info_t *entry,
-                                            herr_t fxn_ret_value);
-H5_DLL herr_t H5AC__write_create_fd_log_msg(const H5AC_t *cache,
-                                            const H5AC_info_t *parent,
-                                            const H5AC_info_t *child,
-                                            herr_t fxn_ret_value);
-H5_DLL herr_t H5AC__write_protect_entry_log_msg(const H5AC_t *cache,
-                                                const H5AC_info_t *entry,
-                                                unsigned flags,
-                                                herr_t fxn_ret_value);
-H5_DLL herr_t H5AC__write_resize_entry_log_msg(const H5AC_t *cache,
-                                               const H5AC_info_t *entry,
-                                               size_t new_size,
-                                               herr_t fxn_ret_value);
-H5_DLL herr_t H5AC__write_unpin_entry_log_msg(const H5AC_t *cache,
-                                              const H5AC_info_t *entry,
-                                              herr_t fxn_ret_value);
-H5_DLL herr_t H5AC__write_destroy_fd_log_msg(const H5AC_t *cache,
-                                             const H5AC_info_t *parent,
-                                             const H5AC_info_t *child,
-                                             herr_t fxn_ret_value);
-H5_DLL herr_t H5AC__write_unprotect_entry_log_msg(const H5AC_t *cache,
-                                                  const H5AC_info_t *entry,
-                                                  int type_id,
-                                                  unsigned flags,
-                                                  herr_t fxn_ret_value);
-H5_DLL herr_t H5AC__write_set_cache_config_log_msg(const H5AC_t *cache,
-                                                   const H5AC_cache_config_t *config,
-                                                   herr_t fxn_ret_value);
-H5_DLL herr_t H5AC__write_remove_entry_log_msg(const H5AC_t *cache,
-                                              const H5AC_info_t *entry,
-                                              herr_t fxn_ret_value);
-
 #endif /* _H5ACpkg_H */
 
diff --git a/src/H5ACprivate.h b/src/H5ACprivate.h
index 0e8620d..e1fdedf 100644
--- a/src/H5ACprivate.h
+++ b/src/H5ACprivate.h
@@ -35,12 +35,6 @@
 #include "H5Pprivate.h"		/* Property lists			*/
 #include "H5SLprivate.h"        /* Skip lists 				*/
 
-#ifdef H5_METADATA_TRACE_FILE
-#define H5AC__TRACE_FILE_ENABLED	1
-#else /* H5_METADATA_TRACE_FILE */
-#define H5AC__TRACE_FILE_ENABLED	0
-#endif /* H5_METADATA_TRACE_FILE */
-
 /* Global metadata tag values */
 #define H5AC__INVALID_TAG      (haddr_t)0
 #define H5AC__IGNORE_TAG       (haddr_t)1
diff --git a/src/H5Adeprec.c b/src/H5Adeprec.c
index d4eac6a..b438cd2 100644
--- a/src/H5Adeprec.c
+++ b/src/H5Adeprec.c
@@ -45,6 +45,8 @@
 #include "H5Opkg.h"             /* Object headers                           */
 #include "H5VLprivate.h"        /* Virtual object layer                     */
 
+#include "H5VLnative_private.h" /* Native VOL connector                     */
+
 
 /****************/
 /* Local Macros */
diff --git a/src/H5Apublic.h b/src/H5Apublic.h
index 726f51b..7162f6e 100644
--- a/src/H5Apublic.h
+++ b/src/H5Apublic.h
@@ -22,10 +22,6 @@
 #include "H5Opublic.h"		/* Object Headers			*/
 #include "H5Tpublic.h"		/* Datatypes				*/
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 /* Information struct for attribute (for H5Aget_info/H5Aget_info_by_idx) */
 typedef struct {
     hbool_t             corder_valid;   /* Indicate if creation order is valid */
@@ -38,23 +34,19 @@ typedef struct {
 typedef herr_t (*H5A_operator2_t)(hid_t location_id/*in*/,
     const char *attr_name/*in*/, const H5A_info_t *ainfo/*in*/, void *op_data/*in,out*/);
 
-/* Enumeration for native VOL connector attribute optional VOL operations */
-typedef enum H5VL_native_attr_optional_t {
-    H5VL_NATIVE_ATTR_ITERATE_OLD        /* H5Aiterate (deprecated routine) */
-                                        /* (This enum value should have an
-                                         *      "#ifndefH5_NO_DEPRECATED_SYMBOLS"
-                                         *      around it, but the compiler
-                                         *      complains about an empty enum
-                                         *      when deprecated symbols are
-                                         *      disabled currently.  When
-                                         *      another enum value is added,
-                                         *      please put the #ifdef around
-                                         *      this symbol.  QAK - 2018/12/06
-                                         */
-} H5VL_native_attr_optional_t;
-
-
-/* Public function prototypes */
+
+/********************/
+/* Public Variables */
+/********************/
+
+
+/*********************/
+/* Public Prototypes */
+/*********************/
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 H5_DLL hid_t   H5Acreate2(hid_t loc_id, const char *attr_name, hid_t type_id,
     hid_t space_id, hid_t acpl_id, hid_t aapl_id);
 H5_DLL hid_t   H5Acreate_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
diff --git a/src/H5C.c b/src/H5C.c
index a22eca0..b5dc6a5 100644
--- a/src/H5C.c
+++ b/src/H5C.c
@@ -282,13 +282,8 @@ H5C_create(size_t		      max_cache_size,
 
     cache_ptr->flush_in_progress		= FALSE;
 
-    cache_ptr->logging_enabled                  = FALSE;
-
-    cache_ptr->currently_logging                = FALSE;
-
-    cache_ptr->log_file_ptr			= NULL;
-
-    cache_ptr->trace_file_ptr			= NULL;
+    if(NULL == (cache_ptr->log_info = (H5C_log_info_t *)H5MM_calloc(sizeof(H5C_log_info_t))))
+        HGOTO_ERROR(H5E_CACHE, H5E_CANTALLOC, NULL, "memory allocation failed")
 
     cache_ptr->aux_ptr				= aux_ptr;
 
@@ -493,6 +488,9 @@ done:
             if(cache_ptr->tag_list != NULL)
                 H5SL_close(cache_ptr->tag_list);
 
+            if(cache_ptr->log_info != NULL)
+                H5MM_xfree(cache_ptr->log_info);
+
             cache_ptr->magic = 0;
             cache_ptr = H5FL_FREE(H5C_t, cache_ptr);
         } /* end if */
@@ -865,6 +863,9 @@ H5C_dest(H5F_t * f)
         cache_ptr->tag_list = NULL;
     } /* end if */
 
+    if(cache_ptr->log_info != NULL)
+        H5MM_xfree(cache_ptr->log_info);
+
 #ifndef NDEBUG
 #if H5C_DO_SANITY_CHECKS
     if(cache_ptr->get_entry_ptr_from_addr_counter > 0)
diff --git a/src/H5Cdbg.c b/src/H5Cdbg.c
index 08c70d9..1f55e86 100644
--- a/src/H5Cdbg.c
+++ b/src/H5Cdbg.c
@@ -476,42 +476,6 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5C_set_trace_file_ptr
- *
- * Purpose:     Set the trace_file_ptr field for the cache.
- *
- *              This field must either be NULL (which turns of trace
- *              file logging), or be a pointer to an open file to which
- *              trace file data is to be written.
- *
- * Return:      Non-negative on success/Negative on failure
- *
- * Programmer:  John Mainzer
- *              1/20/06
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5C_set_trace_file_ptr(H5C_t * cache_ptr, FILE * trace_file_ptr)
-{
-    herr_t		ret_value = SUCCEED;   /* Return value */
-
-    FUNC_ENTER_NOAPI(FAIL)
-
-    /* This would normally be an assert, but we need to use an HGOTO_ERROR
-     * call to shut up the compiler.
-     */
-    if((NULL == cache_ptr) || (cache_ptr->magic != H5C__H5C_T_MAGIC))
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "Bad cache_ptr")
-
-    cache_ptr->trace_file_ptr = trace_file_ptr;
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5C_set_trace_file_ptr() */
-
-
-/*-------------------------------------------------------------------------
  * Function:    H5C_stats
  *
  * Purpose:     Prints statistics about the cache.
diff --git a/src/H5Clog.c b/src/H5Clog.c
index 3353619..0ae7f13 100644
--- a/src/H5Clog.c
+++ b/src/H5Clog.c
@@ -13,11 +13,9 @@
 
 /*-------------------------------------------------------------------------
  *
- * Created:             H5Clog.c
- *                      May 30 2016
- *                      Quincey Koziol
+ * Created:     H5Clog.c
  *
- * Purpose:             Functions for generic cache logging in JSON format
+ * Purpose:     Functions for metadata cache logging
  *
  *-------------------------------------------------------------------------
  */
@@ -30,14 +28,12 @@
 /***********/
 /* Headers */
 /***********/
-#include "H5private.h"          /* Generic Functions                    */
-#ifdef H5_HAVE_PARALLEL
-#define H5AC_FRIEND		/*suppress error about including H5ACpkg	  */
-#include "H5ACpkg.h"            /* Metadata cache                       */
-#endif /* H5_HAVE_PARALLEL */
-#include "H5Cpkg.h"            /* Metadata cache                       */
-#include "H5Eprivate.h"         /* Error handling                       */
-#include "H5MMprivate.h"	/* Memory management			*/
+#include "H5private.h"          /* Generic Functions                        */
+#define H5AC_FRIEND     /* Suppress error about including H5ACpkg */
+#include "H5ACpkg.h"            /* Metadata cache                           */
+#include "H5Cpkg.h"             /* Cache                                    */
+#include "H5Clog.h"             /* Cache logging                            */
+#include "H5Eprivate.h"         /* Error handling                           */
 
 
 /****************/
@@ -77,133 +73,109 @@
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5C_set_up_logging
+ * Function:    H5C_log_set_up
  *
  * Purpose:     Setup for metadata cache logging.
  *
- *              Metadata logging is enabled and disabled at two levels. This
- *              function and the associated tear_down function open and close
- *              the log file. the start_ and stop_logging functions are then
- *              used to switch logging on/off. Optionally, logging can begin
- *              as soon as the log file is opened (set via the start_immediately
- *              parameter to this function).
- *
- *              The log functionality is split between the H5C and H5AC
- *              packages. Log state and direct log manipulation resides in
- *              H5C. Log messages are generated in H5AC and sent to
- *              the H5C_write_log_message function.
+ * Return:      SUCCEED/FAIL
  *
- * Return:      Non-negative on success/Negative on failure
- *
- * Programmer:	Dana Robinson
- *              Sunday, March 16, 2014
+ * Programmer:  Dana Robinson
+ *              Fall 2018
  *
  *-------------------------------------------------------------------------
  */
 herr_t
-H5C_set_up_logging(H5C_t *cache_ptr, const char log_location[],
-    hbool_t start_immediately)
+H5C_log_set_up(H5C_t *cache, const char log_location[], H5C_log_style_t style, hbool_t start_immediately)
 {
-#ifdef H5_HAVE_PARALLEL
-    H5AC_aux_t *aux_ptr = NULL;
-#endif /*H5_HAVE_PARALLEL*/
-    char *file_name = NULL;
-    size_t n_chars;
-    herr_t ret_value = SUCCEED;      /* Return value */
+    int mpi_rank = -1;              /* -1 indicates serial (no MPI rank) */
+    herr_t ret_value = SUCCEED;     /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
 
     /* Sanity checks */
-    if(NULL == cache_ptr)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "cache_ptr == NULL")
-    if(H5C__H5C_T_MAGIC != cache_ptr->magic)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "cache magic value incorrect")
-    if(cache_ptr->logging_enabled)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "logging already set up")
-    if(NULL == log_location)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "NULL log location not allowed")
-
-    /* Possibly fix up the log file name.
-     * The extra 39 characters are for adding the rank to the file name
-     * under parallel HDF5. 39 characters allows > 2^127 processes which
-     * should be enough for anybody.
-     *
-     * allocation size = <path length> + dot + <rank # length> + \0
-     */
-    n_chars = HDstrlen(log_location) + 1 + 39 + 1;
-    if(NULL == (file_name = (char *)H5MM_calloc(n_chars * sizeof(char))))
-        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL, "can't allocate memory for mdc log file name manipulation")
+    HDassert(cache);
+    HDassert(log_location);
 
+    /* Check logging flags */
+    if(cache->log_info->enabled)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "logging already set up")
+
+    /* Get the rank when MPI is in use. Logging clients will usually
+     * use that to create per-process logs.
+     */
 #ifdef H5_HAVE_PARALLEL
-    /* Add the rank to the log file name when MPI is in use */
-    aux_ptr = (H5AC_aux_t *)(cache_ptr->aux_ptr);
-
-    if(NULL == aux_ptr)
-        HDsnprintf(file_name, n_chars, "%s", log_location);
-    else {
-        if(aux_ptr->magic != H5AC__H5AC_AUX_T_MAGIC)
-            HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "bad aux_ptr->magic")
-        HDsnprintf(file_name, n_chars, "%s.%d", log_location, aux_ptr->mpi_rank);
-    } /* end else */
-#else /* H5_HAVE_PARALLEL */
-    HDsnprintf(file_name, n_chars, "%s", log_location);
-#endif /* H5_HAVE_PARALLEL */
-
-    /* Open log file */
-    if(NULL == (cache_ptr->log_file_ptr = HDfopen(file_name, "w")))
-        HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "can't create mdc log file")
+    if(NULL != cache->aux_ptr)
+        mpi_rank = ((H5AC_aux_t *)(cache->aux_ptr))->mpi_rank;
+#endif /*H5_HAVE_PARALLEL*/
+
+    /* Set up logging */
+    if(H5C_LOG_STYLE_JSON == style) {
+        if(H5C_log_json_set_up(cache->log_info, log_location, mpi_rank) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to set up json logging")
+    }
+    else if(H5C_LOG_STYLE_TRACE == style) {
+        if(H5C_log_trace_set_up(cache->log_info, log_location, mpi_rank) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to set up trace logging")
+    }
+    else
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unknown logging style")
 
     /* Set logging flags */
-    cache_ptr->logging_enabled = TRUE;
-    cache_ptr->currently_logging = start_immediately;
+    cache->log_info->enabled = TRUE;
+
+    /* Start logging if requested */
+    if(start_immediately)
+        if(H5C_start_logging(cache) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to start logging")
 
  done:
-    if(file_name)
-        file_name = (char *)H5MM_xfree(file_name);
 
     FUNC_LEAVE_NOAPI(ret_value)
-} /* H5C_set_up_logging() */
+} /* H5C_log_set_up() */
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5C_tear_down_logging
+ * Function:    H5C_log_tear_down
  *
  * Purpose:     Tear-down for metadata cache logging.
  *
- * Return:      Non-negative on success/Negative on failure
+ * Return:      SUCCEED/FAIL
  *
- * Programmer:	Dana Robinson
- *              Sunday, March 16, 2014
+ * Programmer:  Dana Robinson
+ *              Fall 2018
  *
  *-------------------------------------------------------------------------
  */
 herr_t
-H5C_tear_down_logging(H5C_t *cache_ptr)
+H5C_log_tear_down(H5C_t *cache)
 {
     herr_t ret_value = SUCCEED;      /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
 
     /* Sanity checks */
-    if(NULL == cache_ptr)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "cache_ptr == NULL")
-    if(H5C__H5C_T_MAGIC != cache_ptr->magic)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "cache magic value incorrect")
-    if(FALSE == cache_ptr->logging_enabled)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "logging not enabled")
+    HDassert(cache);
 
-    /* Unset logging flags */
-    cache_ptr->logging_enabled = FALSE;
-    cache_ptr->currently_logging = FALSE;
+    /* Check logging flags */
+    if(FALSE == cache->log_info->enabled)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "logging not enabled")
 
-    /* Close log file */
-    if(EOF == HDfclose(cache_ptr->log_file_ptr))
-        HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "problem closing mdc log file")
-    cache_ptr->log_file_ptr = NULL;
+    /* Stop logging if that's going on */
+    if(cache->log_info->logging)
+        if(H5C_stop_logging(cache) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to stop logging")
+
+    /* Tear down logging */
+    if(cache->log_info->cls->tear_down_logging)
+        if(cache->log_info->cls->tear_down_logging(cache->log_info) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific tear down call failed")
+
+    /* Unset logging flags */
+    cache->log_info->enabled = FALSE;
 
  done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* H5C_tear_down_logging() */
+} /* H5C_log_tear_down() */
 
 
 /*-------------------------------------------------------------------------
@@ -211,37 +183,39 @@ H5C_tear_down_logging(H5C_t *cache_ptr)
  *
  * Purpose:     Start logging metadata cache operations.
  *
- *              TODO: Add a function that dumps the current state of the
- *                    metadata cache.
+ * Return:      SUCCEED/FAIL
  *
- * Return:      Non-negative on success/Negative on failure
- *
- * Programmer:	Dana Robinson
- *              Sunday, March 16, 2014
+ * Programmer:  Dana Robinson
+ *              Fall 2018
  *
  *-------------------------------------------------------------------------
  */
 herr_t
-H5C_start_logging(H5C_t *cache_ptr)
+H5C_start_logging(H5C_t *cache)
 {
     herr_t ret_value = SUCCEED;      /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
 
     /* Sanity checks */
-    if(NULL == cache_ptr)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "cache_ptr == NULL")
-    if(H5C__H5C_T_MAGIC != cache_ptr->magic)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "cache magic value incorrect")
-    if(FALSE == cache_ptr->logging_enabled)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "logging not enabled")
-    if(cache_ptr->currently_logging)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "logging already in progress")
+    HDassert(cache);
+
+    /* Check logging flags */
+    if(FALSE == cache->log_info->enabled)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "logging not enabled")
+
+    /* Start logging */
+    if(cache->log_info->cls->start_logging)
+        if(cache->log_info->cls->start_logging(cache->log_info) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific start call failed")
 
     /* Set logging flags */
-    cache_ptr->currently_logging = TRUE;
+    cache->log_info->logging = TRUE;
 
-    /* TODO - Dump cache state */
+    /* Write a log message */
+    if(cache->log_info->cls->write_start_log_msg)
+        if(cache->log_info->cls->write_start_log_msg(cache->log_info->udata) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific write start call failed")
 
  done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -253,32 +227,41 @@ H5C_start_logging(H5C_t *cache_ptr)
  *
  * Purpose:     Stop logging metadata cache operations.
  *
- * Return:      Non-negative on success/Negative on failure
+ * Return:      SUCCEED/FAIL
  *
- * Programmer:	Dana Robinson
- *              Sunday, March 16, 2014
+ * Programmer:  Dana Robinson
+ *              Fall 2018
  *
  *-------------------------------------------------------------------------
  */
 herr_t
-H5C_stop_logging(H5C_t *cache_ptr)
+H5C_stop_logging(H5C_t *cache)
 {
     herr_t ret_value = SUCCEED;      /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
 
     /* Sanity checks */
-    if(NULL == cache_ptr)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "cache_ptr == NULL")
-    if(H5C__H5C_T_MAGIC != cache_ptr->magic)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "cache magic value incorrect")
-    if(FALSE == cache_ptr->logging_enabled)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "logging not enabled")
-    if(FALSE == cache_ptr->currently_logging)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "logging not in progress")
+    HDassert(cache);
+
+    /* Check logging flags */
+    if(FALSE == cache->log_info->enabled)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "logging not enabled")
+    if(FALSE == cache->log_info->logging)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "logging not in progress")
+
+    /* Write a log message */
+    if(cache->log_info->cls->write_stop_log_msg)
+        if(cache->log_info->cls->write_stop_log_msg(cache->log_info->udata) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific write stop call failed")
+
+    /* Stop logging */
+    if(cache->log_info->cls->stop_logging)
+        if(cache->log_info->cls->stop_logging(cache->log_info) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific stop call failed")
 
     /* Set logging flags */
-    cache_ptr->currently_logging = FALSE;
+    cache->log_info->logging = FALSE;
 
  done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -289,80 +272,706 @@ H5C_stop_logging(H5C_t *cache_ptr)
  * Function:    H5C_get_logging_status
  *
  * Purpose:     Determines if the cache is actively logging (via the OUT
- *              parameter).
+ *              parameters).
  *
- * Return:      Non-negative on success/Negative on failure
+ * Return:      SUCCEED/FAIL
  *
- * Programmer:	Dana Robinson
- *              Sunday, March 16, 2014
+ * Programmer:  Dana Robinson
+ *              Fall 2018
  *
  *-------------------------------------------------------------------------
  */
 herr_t
-H5C_get_logging_status(const H5C_t *cache_ptr, /*OUT*/ hbool_t *is_enabled,
+H5C_get_logging_status(const H5C_t *cache, /*OUT*/ hbool_t *is_enabled,
                        /*OUT*/ hbool_t *is_currently_logging)
 {
-    herr_t ret_value = SUCCEED;      /* Return value */
+    FUNC_ENTER_NOAPI_NOERR
+
+    /* Sanity checks */
+    HDassert(cache);
+    HDassert(is_enabled);
+    HDassert(is_currently_logging);
+
+    /* Get logging flags */
+    *is_enabled = cache->log_info->enabled;
+    *is_currently_logging = cache->log_info->logging;
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* H5C_get_logging_status() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C_log_write_create_cache_msg
+ *
+ * Purpose:     Write a log message for cache creation.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_log_write_create_cache_msg(H5C_t *cache, herr_t fxn_ret_value) 
+{
+    herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
 
     /* Sanity checks */
-    if(NULL == cache_ptr)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "cache_ptr == NULL")
-    if(H5C__H5C_T_MAGIC != cache_ptr->magic)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "cache magic value incorrect")
-    if(NULL == is_enabled)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "cache magic value incorrect")
-    if(NULL == is_currently_logging)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "cache magic value incorrect")
-
-    *is_enabled = cache_ptr->logging_enabled;
-    *is_currently_logging = cache_ptr->currently_logging;
+    HDassert(cache);
+
+    /* Write a log message */
+    if(cache->log_info->cls->write_create_cache_log_msg)
+        if(cache->log_info->cls->write_create_cache_log_msg(cache->log_info->udata, fxn_ret_value) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific write create cache call failed")
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* H5C_get_logging_status() */
+} /* H5C_log_write_create_cache_msg() */
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C_log_write_destroy_cache_msg
+ *
+ * Purpose:     Write a log message for cache destruction.
+ *
+ * NOTE:        This can't print out the H5AC call return value, since we
+ *              won't know that until the cache is destroyed and at that
+ *              point we no longer have pointers to the logging information.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_log_write_destroy_cache_msg(H5C_t *cache) 
+{
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(cache);
+
+    /* Write a log message */
+    if(cache->log_info->cls->write_destroy_cache_log_msg)
+        if(cache->log_info->cls->write_destroy_cache_log_msg(cache->log_info->udata) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific write destroy cache call failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_log_write_destroy_cache_msg() */
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5C_write_log_message
+ * Function:    H5C_log_write_evict_cache_msg
  *
- * Purpose:     Write a message to the log file and flush the file. 
- *              The message string is neither modified nor freed.
+ * Purpose:     Write a log message for eviction of cache entries.
  *
- * Return:      Non-negative on success/Negative on failure
+ * Return:      SUCCEED/FAIL
  *
- * Programmer:	Dana Robinson
- *              Sunday, March 16, 2014
+ * Programmer:  Dana Robinson
+ *              Fall 2018
  *
  *-------------------------------------------------------------------------
  */
 herr_t
-H5C_write_log_message(const H5C_t *cache_ptr, const char message[])
+H5C_log_write_evict_cache_msg(H5C_t *cache, herr_t fxn_ret_value)
 {
-    size_t n_chars;
-    herr_t ret_value = SUCCEED;      /* Return value */
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(cache);
+
+    /* Write a log message */
+    if(cache->log_info->cls->write_evict_cache_log_msg)
+        if(cache->log_info->cls->write_evict_cache_log_msg(cache->log_info->udata, fxn_ret_value) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific write evict cache call failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_log_write_evict_cache_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C_log_write_expunge_entry_msg
+ *
+ * Purpose:     Write a log message for expunge of cache entries.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_log_write_expunge_entry_msg(H5C_t *cache, haddr_t address,
+    int type_id, herr_t fxn_ret_value)
+{
+    herr_t ret_value = SUCCEED;
 
     FUNC_ENTER_NOAPI(FAIL)
 
     /* Sanity checks */
-    if(NULL == cache_ptr)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "cache_ptr == NULL")
-    if(H5C__H5C_T_MAGIC != cache_ptr->magic)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "cache magic value incorrect")
-    if(FALSE == cache_ptr->currently_logging)
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "not currently logging")
-    if(NULL == message)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "NULL log message not allowed")
-
-    /* Write the log message and flush */
-    n_chars = HDstrlen(message);
-    if((int)n_chars != HDfprintf(cache_ptr->log_file_ptr, message))
-        HGOTO_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL, "error writing log message")
-    if(EOF == HDfflush(cache_ptr->log_file_ptr))
-        HGOTO_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL, "error flushing log message")
+    HDassert(cache);
+
+    /* Write a log message */
+    if(cache->log_info->cls->write_expunge_entry_log_msg)
+        if(cache->log_info->cls->write_expunge_entry_log_msg(cache->log_info->udata, address, type_id, fxn_ret_value) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific write expunge entry call failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_log_write_expunge_entry_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C_log_write_flush_cache_msg
+ *
+ * Purpose:     Write a log message for cache flushes.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_log_write_flush_cache_msg(H5C_t *cache, herr_t fxn_ret_value)
+{
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(cache);
+
+    /* Write a log message */
+    if(cache->log_info->cls->write_flush_cache_log_msg)
+        if(cache->log_info->cls->write_flush_cache_log_msg(cache->log_info->udata, fxn_ret_value) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific flush cache call failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_log_write_flush_cache_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C_log_write_insert_entry_msg
+ *
+ * Purpose:     Write a log message for insertion of cache entries.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_log_write_insert_entry_msg(H5C_t *cache, haddr_t address,
+    int type_id, unsigned flags, size_t size, herr_t fxn_ret_value)
+{
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(cache);
+
+    /* Write a log message */
+    if(cache->log_info->cls->write_insert_entry_log_msg)
+        if(cache->log_info->cls->write_insert_entry_log_msg(cache->log_info->udata, address, type_id, flags, size, fxn_ret_value) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific insert entry call failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_log_write_insert_entry_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C_log_write_mark_entry_dirty_msg
+ *
+ * Purpose:     Write a log message for marking cache entries as dirty.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_log_write_mark_entry_dirty_msg(H5C_t *cache, const H5C_cache_entry_t *entry,
+    herr_t fxn_ret_value)
+{
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(cache);
+
+    /* Write a log message */
+    HDassert(entry);
+    if(cache->log_info->cls->write_mark_entry_dirty_log_msg)
+        if(cache->log_info->cls->write_mark_entry_dirty_log_msg(cache->log_info->udata, entry, fxn_ret_value) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific mark dirty entry call failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_log_write_mark_entry_dirty_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C_log_write_mark_entry_clean_msg
+ *
+ * Purpose:     Write a log message for marking cache entries as clean.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_log_write_mark_entry_clean_msg(H5C_t *cache, const H5C_cache_entry_t *entry,
+    herr_t fxn_ret_value)
+{
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(cache);
+
+    /* Write a log message */
+    HDassert(entry);
+    if(cache->log_info->cls->write_mark_entry_clean_log_msg)
+        if(cache->log_info->cls->write_mark_entry_clean_log_msg(cache->log_info->udata, entry, fxn_ret_value) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific mark clean entry call failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_log_write_mark_entry_clean_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C_log_write_mark_unserialized_entry_msg
+ *
+ * Purpose:     Write a log message for marking cache entries as unserialized.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_log_write_mark_unserialized_entry_msg(H5C_t *cache,
+    const H5C_cache_entry_t *entry, herr_t fxn_ret_value)
+{
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(cache);
+
+    /* Write a log message */
+    HDassert(entry);
+    if(cache->log_info->cls->write_mark_unserialized_entry_log_msg)
+        if(cache->log_info->cls->write_mark_unserialized_entry_log_msg(cache->log_info->udata, entry, fxn_ret_value) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific mark unserialized entry call failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_log_write_mark_unserialized_entry_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C_log_write_mark_serialized_entry_msg
+ *
+ * Purpose:     Write a log message for marking cache entries as serialize.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_log_write_mark_serialized_entry_msg(H5C_t *cache, const H5C_cache_entry_t *entry,
+    herr_t fxn_ret_value)
+{
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(cache);
+
+    /* Write a log message */
+    HDassert(entry);
+    if(cache->log_info->cls->write_mark_serialized_entry_log_msg)
+        if(cache->log_info->cls->write_mark_serialized_entry_log_msg(cache->log_info->udata, entry, fxn_ret_value) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific mark serialized entry call failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_log_write_mark_serialized_entry_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C_log_write_move_entry_msg
+ *
+ * Purpose:     Write a log message for moving a cache entry.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_log_write_move_entry_msg(H5C_t *cache, haddr_t old_addr, haddr_t new_addr,
+    int type_id, herr_t fxn_ret_value)
+{
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(cache);
+
+    /* Write a log message */
+    if(cache->log_info->cls->write_move_entry_log_msg)
+        if(cache->log_info->cls->write_move_entry_log_msg(cache->log_info->udata, old_addr, new_addr, type_id, fxn_ret_value) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific move entry call failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_log_write_move_entry_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C_log_write_pin_entry_msg
+ *
+ * Purpose:     Write a log message for pinning a cache entry.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_log_write_pin_entry_msg(H5C_t *cache, const H5C_cache_entry_t *entry,
+    herr_t fxn_ret_value)
+{
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(cache);
+
+    /* Write a log message */
+    HDassert(entry);
+    if(cache->log_info->cls->write_pin_entry_log_msg)
+        if(cache->log_info->cls->write_pin_entry_log_msg(cache->log_info->udata, entry, fxn_ret_value) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific pin entry call failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_log_write_pin_entry_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C_log_write_create_fd_msg
+ *
+ * Purpose:     Write a log message for creating a flush dependency between
+ *              two cache entries.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_log_write_create_fd_msg(H5C_t *cache, const H5C_cache_entry_t *parent,
+    const H5C_cache_entry_t *child, herr_t fxn_ret_value)
+{
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(cache);
+
+    /* Write a log message */
+    HDassert(parent);
+    HDassert(child);
+    if(cache->log_info->cls->write_create_fd_log_msg)
+        if(cache->log_info->cls->write_create_fd_log_msg(cache->log_info->udata, parent, child, fxn_ret_value) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific create fd call failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_log_write_create_fd_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C_log_write_protect_entry_msg
+ *
+ * Purpose:     Write a log message for protecting a cache entry.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_log_write_protect_entry_msg(H5C_t *cache, const H5C_cache_entry_t *entry,
+    int type_id, unsigned flags, herr_t fxn_ret_value)
+{
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(cache);
+
+    /* Write a log message */
+    HDassert(entry);
+    if(cache->log_info->cls->write_protect_entry_log_msg)
+        if(cache->log_info->cls->write_protect_entry_log_msg(cache->log_info->udata, entry, type_id, flags, fxn_ret_value) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific protect entry call failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_log_write_protect_entry_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C_log_write_resize_entry_msg
+ *
+ * Purpose:     Write a log message for resizing a cache entry.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_log_write_resize_entry_msg(H5C_t *cache, const H5C_cache_entry_t *entry,
+    size_t new_size, herr_t fxn_ret_value)
+{
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(cache);
+
+    /* Write a log message */
+    HDassert(entry);
+    if(cache->log_info->cls->write_resize_entry_log_msg)
+        if(cache->log_info->cls->write_resize_entry_log_msg(cache->log_info->udata, entry, new_size, fxn_ret_value) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific resize entry call failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_log_write_resize_entry_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C_log_write_unpin_entry_msg
+ *
+ * Purpose:     Write a log message for unpinning a cache entry.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_log_write_unpin_entry_msg(H5C_t *cache, const H5C_cache_entry_t *entry,
+    herr_t fxn_ret_value)
+{
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(cache);
+
+    /* Write a log message */
+    HDassert(entry);
+    if(cache->log_info->cls->write_unpin_entry_log_msg)
+        if(cache->log_info->cls->write_unpin_entry_log_msg(cache->log_info->udata, entry, fxn_ret_value) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific unpin entry call failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_log_write_unpin_entry_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C_log_write_destroy_fd_msg
+ *
+ * Purpose:     Write a log message for destroying a flush dependency
+ *              between two cache entries.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_log_write_destroy_fd_msg(H5C_t *cache, const H5C_cache_entry_t *parent,
+    const H5C_cache_entry_t *child, herr_t fxn_ret_value)
+{
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(cache);
+
+    /* Write a log message */
+    HDassert(parent);
+    HDassert(child);
+    if(cache->log_info->cls->write_destroy_fd_log_msg)
+        if(cache->log_info->cls->write_destroy_fd_log_msg(cache->log_info->udata, parent, child, fxn_ret_value) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific destroy fd call failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_log_write_destroy_fd_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C_log_write_unprotect_entry_msg
+ *
+ * Purpose:     Write a log message for unprotecting a cache entry.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_log_write_unprotect_entry_msg(H5C_t *cache, const H5C_cache_entry_t *entry,
+    int type_id, unsigned flags, herr_t fxn_ret_value)
+{
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(cache);
+
+    /* Write a log message */
+    HDassert(entry);
+    if(cache->log_info->cls->write_unprotect_entry_log_msg)
+        if(cache->log_info->cls->write_unprotect_entry_log_msg(cache->log_info->udata, entry, type_id, flags, fxn_ret_value) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific unprotect entry call failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_log_write_unprotect_entry_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C_log_write_set_cache_config_msg
+ *
+ * Purpose:     Write a log message for setting the cache configuration.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_log_write_set_cache_config_msg(H5C_t *cache, const H5AC_cache_config_t *config,
+    herr_t fxn_ret_value)
+{
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(cache);
+
+    /* Write a log message */
+    HDassert(config);
+    if(cache->log_info->cls->write_set_cache_config_log_msg)
+        if(cache->log_info->cls->write_set_cache_config_log_msg(cache->log_info->udata, config, fxn_ret_value) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific set cache config call failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_log_write_set_cache_config_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C_log_write_remove_entry_msg
+ *
+ * Purpose:     Write a log message for removing a cache entry.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_log_write_remove_entry_msg(H5C_t *cache, const H5C_cache_entry_t *entry,
+    herr_t fxn_ret_value)
+{
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(cache);
+
+    /* Write a log message */
+    HDassert(entry);
+    if(cache->log_info->cls->write_remove_entry_log_msg)
+        if(cache->log_info->cls->write_remove_entry_log_msg(cache->log_info->udata, entry, fxn_ret_value) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "log-specific remove entry call failed")
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* H5C_write_log_message() */
+} /* H5C_log_write_remove_entry_msg() */
 
diff --git a/src/H5Clog.h b/src/H5Clog.h
new file mode 100644
index 0000000..9ba6786
--- /dev/null
+++ b/src/H5Clog.h
@@ -0,0 +1,114 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*
+ * Purpose:     Cache logging header file
+ */
+
+#ifndef _H5Clog_H
+#define _H5Clog_H
+
+/* Get package's private header */
+#include "H5Cprivate.h"         /* Cache                                    */
+
+/**************************/
+/* Package Private Macros */
+/**************************/
+
+/****************************/
+/* Package Private Typedefs */
+/****************************/
+
+/* Forward declaration for class struct */
+typedef struct H5C_log_info_t H5C_log_info_t;
+
+/* Class for generating logging messages */
+typedef struct H5C_log_class_t {
+    const char	*name;				/* String for debugging */
+
+    /* Callbacks for writing log messages */
+    herr_t (*tear_down_logging)(H5C_log_info_t *log_info);
+    herr_t (*start_logging)(H5C_log_info_t *log_info);
+    herr_t (*stop_logging)(H5C_log_info_t *log_info);
+    herr_t (*write_start_log_msg)(void *udata);
+    herr_t (*write_stop_log_msg)(void *udata);
+    herr_t (*write_create_cache_log_msg)(void *udata, herr_t fxn_ret_value);
+    herr_t (*write_destroy_cache_log_msg)(void *udata);
+    herr_t (*write_evict_cache_log_msg)(void *udata, herr_t fxn_ret_value);
+    herr_t (*write_expunge_entry_log_msg)(void *udata, haddr_t address, int type_id, herr_t fxn_ret_value);
+    herr_t (*write_flush_cache_log_msg)(void *udata, herr_t fxn_ret_value);
+    herr_t (*write_insert_entry_log_msg)(void *udata, haddr_t address, int type_id, unsigned flags, size_t size, herr_t fxn_ret_value);
+    herr_t (*write_mark_entry_dirty_log_msg)(void *udata, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+    herr_t (*write_mark_entry_clean_log_msg)(void *udata, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+    herr_t (*write_mark_unserialized_entry_log_msg)(void *udata, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+    herr_t (*write_mark_serialized_entry_log_msg)(void *udata, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+    herr_t (*write_move_entry_log_msg)(void *udata, haddr_t old_addr, haddr_t new_addr, int type_id, herr_t fxn_ret_value);
+    herr_t (*write_pin_entry_log_msg)(void *udata, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+    herr_t (*write_create_fd_log_msg)(void *udata, const H5C_cache_entry_t *parent, const H5C_cache_entry_t *child, herr_t fxn_ret_value);
+    herr_t (*write_protect_entry_log_msg)(void *udata, const H5C_cache_entry_t *entry, int type_id, unsigned flags, herr_t fxn_ret_value);
+    herr_t (*write_resize_entry_log_msg)(void *udata, const H5C_cache_entry_t *entry, size_t new_size, herr_t fxn_ret_value);
+    herr_t (*write_unpin_entry_log_msg)(void *udata, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+    herr_t (*write_destroy_fd_log_msg)(void *udata, const H5C_cache_entry_t *parent, const H5C_cache_entry_t *child, herr_t fxn_ret_value);
+    herr_t (*write_unprotect_entry_log_msg)(void *udata, const H5C_cache_entry_t *entry, int type_id, unsigned flags, herr_t fxn_ret_value);
+    herr_t (*write_set_cache_config_log_msg)(void *udata, const H5AC_cache_config_t *config, herr_t fxn_ret_value);
+    herr_t (*write_remove_entry_log_msg)(void *udata, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+
+} H5C_log_class_t;
+
+/* Logging information */
+struct H5C_log_info_t {
+    hbool_t             enabled;                /* Was the logging set up? */
+    hbool_t             logging;                /* Are we currently logging? */
+    H5C_log_class_t    *cls;                    /* Callbacks for writing log messages */
+    void               *udata;                  /* Log-specific data */
+};
+
+
+/*****************************/
+/* Package Private Variables */
+/*****************************/
+
+
+/******************************/
+/* Package Private Prototypes */
+/******************************/
+H5_DLL herr_t H5C_log_set_up(H5C_t *cache, const char log_location[], H5C_log_style_t style, hbool_t start_immediately);
+H5_DLL herr_t H5C_log_tear_down(H5C_t *cache);
+
+H5_DLL herr_t H5C_log_write_create_cache_msg(H5C_t *cache, herr_t fxn_ret_value);
+H5_DLL herr_t H5C_log_write_destroy_cache_msg(H5C_t *cache);
+H5_DLL herr_t H5C_log_write_evict_cache_msg(H5C_t *cache, herr_t fxn_ret_value);
+H5_DLL herr_t H5C_log_write_expunge_entry_msg(H5C_t *cache, haddr_t address, int type_id, herr_t fxn_ret_value);
+H5_DLL herr_t H5C_log_write_flush_cache_msg(H5C_t *cache, herr_t fxn_ret_value);
+H5_DLL herr_t H5C_log_write_insert_entry_msg(H5C_t *cache, haddr_t address, int type_id, unsigned flags, size_t size, herr_t fxn_ret_value);
+H5_DLL herr_t H5C_log_write_mark_entry_dirty_msg(H5C_t *cache, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+H5_DLL herr_t H5C_log_write_mark_entry_clean_msg(H5C_t *cache, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+H5_DLL herr_t H5C_log_write_mark_unserialized_entry_msg(H5C_t *cache, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+H5_DLL herr_t H5C_log_write_mark_serialized_entry_msg(H5C_t *cache, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+H5_DLL herr_t H5C_log_write_move_entry_msg(H5C_t *cache, haddr_t old_addr, haddr_t new_addr, int type_id, herr_t fxn_ret_value);
+H5_DLL herr_t H5C_log_write_pin_entry_msg(H5C_t *cache, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+H5_DLL herr_t H5C_log_write_create_fd_msg(H5C_t *cache, const H5C_cache_entry_t *parent, const H5C_cache_entry_t *child, herr_t fxn_ret_value);
+H5_DLL herr_t H5C_log_write_protect_entry_msg(H5C_t *cache, const H5C_cache_entry_t *entry, int type_id, unsigned flags, herr_t fxn_ret_value);
+H5_DLL herr_t H5C_log_write_resize_entry_msg(H5C_t *cache, const H5C_cache_entry_t *entry, size_t new_size, herr_t fxn_ret_value);
+H5_DLL herr_t H5C_log_write_unpin_entry_msg(H5C_t *cache, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+H5_DLL herr_t H5C_log_write_destroy_fd_msg(H5C_t *cache, const H5C_cache_entry_t *parent, const H5C_cache_entry_t *child, herr_t fxn_ret_value);
+H5_DLL herr_t H5C_log_write_unprotect_entry_msg(H5C_t *cache, const H5C_cache_entry_t *entry, int type_id, unsigned flags, herr_t fxn_ret_value);
+H5_DLL herr_t H5C_log_write_set_cache_config_msg(H5C_t *cache, const H5AC_cache_config_t *config, herr_t fxn_ret_value);
+H5_DLL herr_t H5C_log_write_remove_entry_msg(H5C_t *cache, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+
+/* Logging-specific setup functions */
+H5_DLL herr_t H5C_log_json_set_up(H5C_log_info_t *log_info, const char log_location[], int mpi_rank);
+H5_DLL herr_t H5C_log_trace_set_up(H5C_log_info_t *log_info, const char log_location[], int mpi_rank);
+
+#endif /* _H5Clog_H */
+
diff --git a/src/H5Clog_json.c b/src/H5Clog_json.c
new file mode 100644
index 0000000..ccfa222
--- /dev/null
+++ b/src/H5Clog_json.c
@@ -0,0 +1,1365 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*-------------------------------------------------------------------------
+ *
+ * Created:     H5Clog_json.c
+ *
+ * Purpose:     Cache log implementation that emits JSON-formatted log
+ *              entries for consumption by new-fangled data analysis tools.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/****************/
+/* Module Setup */
+/****************/
+#include "H5Cmodule.h"         /* This source code file is part of the H5C module */
+
+/***********/
+/* Headers */
+/***********/
+#include "H5private.h"          /* Generic Functions                        */
+#include "H5Cpkg.h"             /* Cache                                    */
+#include "H5Clog.h"             /* Cache logging                            */
+#include "H5Eprivate.h"         /* Error handling                           */
+#include "H5MMprivate.h"        /* Memory management                        */
+
+
+/****************/
+/* Local Macros */
+/****************/
+
+/* Max log message size */
+#define H5C_MAX_JSON_LOG_MSG_SIZE 128
+
+
+/******************/
+/* Local Typedefs */
+/******************/
+
+
+/********************/
+/* Package Typedefs */
+/********************/
+
+typedef struct H5C_log_json_udata_t {
+    FILE *outfile;
+    char *message;
+} H5C_log_json_udata_t;
+
+
+/********************/
+/* Local Prototypes */
+/********************/
+
+/* Internal message handling calls */
+static herr_t H5C__json_write_log_message(H5C_log_json_udata_t *json_udata);
+
+/* Log message callbacks */
+static herr_t H5C__json_tear_down_logging(H5C_log_info_t *log_info);
+static herr_t H5C__json_write_start_log_msg(void *udata);
+static herr_t H5C__json_write_stop_log_msg(void *udata);
+static herr_t H5C__json_write_create_cache_log_msg(void *udata, herr_t fxn_ret_value);
+static herr_t H5C__json_write_destroy_cache_log_msg(void *udata);
+static herr_t H5C__json_write_evict_cache_log_msg(void *udata, herr_t fxn_ret_value);
+static herr_t H5C__json_write_expunge_entry_log_msg(void *udata, haddr_t address, int type_id, herr_t fxn_ret_value);
+static herr_t H5C__json_write_flush_cache_log_msg(void *udata, herr_t fxn_ret_value);
+static herr_t H5C__json_write_insert_entry_log_msg(void *udata, haddr_t address, int type_id, unsigned flags, size_t size, herr_t fxn_ret_value);
+static herr_t H5C__json_write_mark_entry_dirty_log_msg(void *udata, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+static herr_t H5C__json_write_mark_entry_clean_log_msg(void *udata, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+static herr_t H5C__json_write_mark_unserialized_entry_log_msg(void *udata, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+static herr_t H5C__json_write_mark_serialized_entry_log_msg(void *udata, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+static herr_t H5C__json_write_move_entry_log_msg(void *udata, haddr_t old_addr, haddr_t new_addr, int type_id, herr_t fxn_ret_value);
+static herr_t H5C__json_write_pin_entry_log_msg(void *udata, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+static herr_t H5C__json_write_create_fd_log_msg(void *udata, const H5C_cache_entry_t *parent, const H5C_cache_entry_t *child, herr_t fxn_ret_value);
+static herr_t H5C__json_write_protect_entry_log_msg(void *udata, const H5C_cache_entry_t *entry, int type_id, unsigned flags, herr_t fxn_ret_value);
+static herr_t H5C__json_write_resize_entry_log_msg(void *udata, const H5C_cache_entry_t *entry, size_t new_size, herr_t fxn_ret_value);
+static herr_t H5C__json_write_unpin_entry_log_msg(void *udata, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+static herr_t H5C__json_write_destroy_fd_log_msg(void *udata, const H5C_cache_entry_t *parent, const H5C_cache_entry_t *child, herr_t fxn_ret_value);
+static herr_t H5C__json_write_unprotect_entry_log_msg(void *udata, const H5C_cache_entry_t *entry, int type_id, unsigned flags, herr_t fxn_ret_value);
+static herr_t H5C__json_write_set_cache_config_log_msg(void *udata, const H5AC_cache_config_t *config, herr_t fxn_ret_value);
+static herr_t H5C__json_write_remove_entry_log_msg(void *udata, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+
+
+/*********************/
+/* Package Variables */
+/*********************/
+
+
+/*****************************/
+/* Library Private Variables */
+/*****************************/
+
+
+/*******************/
+/* Local Variables */
+/*******************/
+
+/* Note that there's no cache set up call since that's the
+ * place where this struct is wired into the cache.
+ */
+static H5C_log_class_t H5C_json_log_class_g = {
+    "json",
+    H5C__json_tear_down_logging,
+    NULL,                               /* start logging */
+    NULL,                               /* stop logging */
+    H5C__json_write_start_log_msg,
+    H5C__json_write_stop_log_msg,
+    H5C__json_write_create_cache_log_msg,
+    H5C__json_write_destroy_cache_log_msg,
+    H5C__json_write_evict_cache_log_msg,
+    H5C__json_write_expunge_entry_log_msg,
+    H5C__json_write_flush_cache_log_msg,
+    H5C__json_write_insert_entry_log_msg,
+    H5C__json_write_mark_entry_dirty_log_msg,
+    H5C__json_write_mark_entry_clean_log_msg,
+    H5C__json_write_mark_unserialized_entry_log_msg,
+    H5C__json_write_mark_serialized_entry_log_msg,
+    H5C__json_write_move_entry_log_msg,
+    H5C__json_write_pin_entry_log_msg,
+    H5C__json_write_create_fd_log_msg,
+    H5C__json_write_protect_entry_log_msg,
+    H5C__json_write_resize_entry_log_msg,
+    H5C__json_write_unpin_entry_log_msg,
+    H5C__json_write_destroy_fd_log_msg,
+    H5C__json_write_unprotect_entry_log_msg,
+    H5C__json_write_set_cache_config_log_msg,
+    H5C__json_write_remove_entry_log_msg
+};
+
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_log_message
+ *
+ * Purpose:     Write a message to the log file and flush the file. 
+ *              The message string is neither modified nor freed.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_log_message(H5C_log_json_udata_t *json_udata)
+{
+    size_t n_chars;
+    herr_t ret_value = SUCCEED;      /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->outfile);
+    HDassert(json_udata->message);
+
+    /* Write the log message and flush */
+    n_chars = HDstrlen(json_udata->message);
+    if((int)n_chars != HDfprintf(json_udata->outfile, json_udata->message))
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "error writing log message")
+    HDmemset((void *)(json_udata->message), 0, (size_t)(n_chars * sizeof(char)));
+            
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_log_message() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C_log_json_set_up
+ *
+ * Purpose:     Setup for metadata cache logging.
+ *
+ *              Metadata logging is enabled and disabled at two levels. This
+ *              function and the associated tear_down function open and close
+ *              the log file. the start_ and stop_logging functions are then
+ *              used to switch logging on/off. Optionally, logging can begin
+ *              as soon as the log file is opened (set via the start_immediately
+ *              parameter to this function).
+ *
+ *              The log functionality is split between the H5C and H5AC
+ *              packages. Log state and direct log manipulation resides in
+ *              H5C. Log messages are generated in H5AC and sent to
+ *              the H5C__json_write_log_message function.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_log_json_set_up(H5C_log_info_t *log_info, const char log_location[], int mpi_rank)
+{
+    H5C_log_json_udata_t *json_udata = NULL;
+    char *file_name = NULL;
+    size_t n_chars;
+    herr_t ret_value = SUCCEED;      /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(log_info);
+    HDassert(log_location);
+
+    /* Set up the class struct */
+    log_info->cls = &H5C_json_log_class_g;
+
+    /* Allocate memory for the JSON-specific data */
+    if(NULL == (log_info->udata = H5MM_calloc(sizeof(H5C_log_json_udata_t))))
+        HGOTO_ERROR(H5E_CACHE, H5E_CANTALLOC, FAIL, "memory allocation failed")
+    json_udata = (H5C_log_json_udata_t *)(log_info->udata);
+    
+    /* Allocate memory for the message buffer */
+    if(NULL == (json_udata->message = (char *)H5MM_calloc(H5C_MAX_JSON_LOG_MSG_SIZE * sizeof(char))))
+        HGOTO_ERROR(H5E_CACHE, H5E_CANTALLOC, FAIL, "memory allocation failed")
+
+    /* Possibly fix up the log file name.
+     * The extra 39 characters are for adding the rank to the file name
+     * under parallel HDF5. 39 characters allows > 2^127 processes which
+     * should be enough for anybody.
+     *
+     * allocation size = "RANK_" + <rank # length> + dot + <path length> + \0
+     */
+    n_chars = 5 + 39 + 1 + HDstrlen(log_location) + 1;
+    if(NULL == (file_name = (char *)H5MM_calloc(n_chars * sizeof(char))))
+        HGOTO_ERROR(H5E_CACHE, H5E_CANTALLOC, FAIL, "can't allocate memory for mdc log file name manipulation")
+
+    /* Add the rank to the log file name when MPI is in use */
+    if(-1 == mpi_rank)
+        HDsnprintf(file_name, n_chars, "%s", log_location);
+    else
+        HDsnprintf(file_name, n_chars, "RANK_%d.%s", mpi_rank, log_location);
+
+    /* Open log file and set it to be unbuffered */
+    if(NULL == (json_udata->outfile = HDfopen(file_name, "w")))
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "can't create mdc log file")
+    HDsetbuf(json_udata->outfile, NULL);
+
+ done:
+    if(file_name)
+        H5MM_xfree(file_name);
+
+    /* Free and reset the log info struct on errors */
+    if(FAIL == ret_value) {
+        /* Free */
+        if(json_udata && json_udata->message)
+            H5MM_xfree(json_udata->message);
+        if(json_udata)
+            H5MM_xfree(json_udata);
+
+        /* Reset */
+        log_info->udata = NULL;
+        log_info->cls = NULL;
+    }
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_log_json_set_up() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_tear_down_logging
+ *
+ * Purpose:     Tear-down for metadata cache logging.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_tear_down_logging(H5C_log_info_t *log_info)
+{
+    H5C_log_json_udata_t *json_udata = NULL;
+    herr_t ret_value = SUCCEED;      /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(log_info);
+
+    /* Alias */
+    json_udata = (H5C_log_json_udata_t *)(log_info->udata);
+
+    /* Free the message buffer */
+    H5MM_xfree(json_udata->message);
+
+    /* Close log file */
+    if(EOF == HDfclose(json_udata->outfile))
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "problem closing mdc log file")
+    json_udata->outfile = NULL;
+
+    /* Fre the udata */
+    H5MM_xfree(json_udata);
+
+    /* Reset the log class info and udata */
+    log_info->cls = NULL;
+    log_info->udata = NULL;
+
+ done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_tear_down_logging() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_start_log_msg
+ *
+ * Purpose:     Write a log message when logging starts.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_start_log_msg(void *udata)
+{
+    H5C_log_json_udata_t *json_udata = (H5C_log_json_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->message);
+
+    /* Create the log message string (opens the JSON array) */
+    HDsnprintf(json_udata->message, H5C_MAX_JSON_LOG_MSG_SIZE, 
+"\
+{\n\
+\"HDF5 metadata cache log messages\" : [\n\
+{\
+\"timestamp\":%lld,\
+\"action\":\"logging start\"\
+},\n\
+"
+    , (long long)HDtime(NULL));
+
+    /* Write the log message to the file */
+    if(H5C__json_write_log_message(json_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_start_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_stop_log_msg
+ *
+ * Purpose:     Write a log message when logging ends.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_stop_log_msg(void *udata)
+{
+    H5C_log_json_udata_t *json_udata = (H5C_log_json_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->message);
+
+    /* Create the log message string (closes the JSON array) */
+    HDsnprintf(json_udata->message, H5C_MAX_JSON_LOG_MSG_SIZE, 
+"\
+{\
+\"timestamp\":%lld,\
+\"action\":\"logging stop\"\
+}\n\
+]}\n\
+"
+    , (long long)HDtime(NULL));
+
+    /* Write the log message to the file */
+    if(H5C__json_write_log_message(json_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+ 
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_stop_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_create_cache_log_msg
+ *
+ * Purpose:     Write a log message for cache creation.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_create_cache_log_msg(void *udata, herr_t fxn_ret_value) 
+{
+    H5C_log_json_udata_t *json_udata = (H5C_log_json_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->message);
+
+    /* Create the log message string */
+    HDsnprintf(json_udata->message, H5C_MAX_JSON_LOG_MSG_SIZE, 
+"\
+{\
+\"timestamp\":%lld,\
+\"action\":\"create\",\
+\"returned\":%d\
+},\n\
+"
+    , (long long)HDtime(NULL), (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__json_write_log_message(json_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_create_cache_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_destroy_cache_log_msg
+ *
+ * Purpose:     Write a log message for cache destruction.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_destroy_cache_log_msg(void *udata)
+{
+    H5C_log_json_udata_t *json_udata = (H5C_log_json_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->message);
+
+    /* Create the log message string */
+    HDsnprintf(json_udata->message, H5C_MAX_JSON_LOG_MSG_SIZE, 
+"\
+{\
+\"timestamp\":%lld,\
+\"action\":\"destroy\"\
+},\n\
+"
+    , (long long)HDtime(NULL));
+
+    /* Write the log message to the file */
+    if(H5C__json_write_log_message(json_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_destroy_cache_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_evict_cache_log_msg
+ *
+ * Purpose:     Write a log message for eviction of cache entries.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_evict_cache_log_msg(void *udata, herr_t fxn_ret_value)
+{
+    H5C_log_json_udata_t *json_udata = (H5C_log_json_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->message);
+
+    /* Create the log message string */
+    HDsnprintf(json_udata->message, H5C_MAX_JSON_LOG_MSG_SIZE, 
+"\
+{\
+\"timestamp\":%lld,\
+\"action\":\"evict\",\
+\"returned\":%d\
+},\n\
+"
+    , (long long)HDtime(NULL), (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__json_write_log_message(json_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_evict_cache_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_expunge_entry_log_msg
+ *
+ * Purpose:     Write a log message for expunge of cache entries.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_expunge_entry_log_msg(void *udata, haddr_t address,
+    int type_id, herr_t fxn_ret_value)
+{
+    H5C_log_json_udata_t *json_udata = (H5C_log_json_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->message);
+
+    /* Create the log message string */
+    HDsnprintf(json_udata->message, H5C_MAX_JSON_LOG_MSG_SIZE, 
+"\
+{\
+\"timestamp\":%lld,\
+\"action\":\"expunge\",\
+\"address\":0x%lx,\
+\"type_id\":%d,\
+\"returned\":%d\
+},\n\
+"
+    , (long long)HDtime(NULL), (unsigned long)address, (int)type_id, (int)fxn_ret_value);
+
+
+    /* Write the log message to the file */
+    if(H5C__json_write_log_message(json_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_expunge_entry_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_flush_cache_log_msg
+ *
+ * Purpose:     Write a log message for cache flushes.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_flush_cache_log_msg(void *udata, herr_t fxn_ret_value)
+{
+    H5C_log_json_udata_t *json_udata = (H5C_log_json_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->message);
+
+    /* Create the log message string */
+    HDsnprintf(json_udata->message, H5C_MAX_JSON_LOG_MSG_SIZE, 
+"\
+{\
+\"timestamp\":%lld,\
+\"action\":\"flush\",\
+\"returned\":%d\
+},\n\
+"
+    , (long long)HDtime(NULL), (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__json_write_log_message(json_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_flush_cache_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_insert_entry_log_msg
+ *
+ * Purpose:     Write a log message for insertion of cache entries.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_insert_entry_log_msg(void *udata, haddr_t address,
+    int type_id, unsigned flags, size_t size, herr_t fxn_ret_value)
+{
+    H5C_log_json_udata_t *json_udata = (H5C_log_json_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->message);
+
+    /* Create the log message string */
+    HDsnprintf(json_udata->message, H5C_MAX_JSON_LOG_MSG_SIZE, 
+"\
+{\
+\"timestamp\":%lld,\
+\"action\":\"insert\",\
+\"address\":0x%lx,\
+\"type_id\":%d,\
+\"flags\":0x%x,\
+\"size\":%d,\
+\"returned\":%d\
+},\n\
+"
+    , (long long)HDtime(NULL), (unsigned long)address, type_id, flags,
+      (int)size, (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__json_write_log_message(json_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_insert_entry_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_mark_entry_dirty_log_msg
+ *
+ * Purpose:     Write a log message for marking cache entries as dirty.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_mark_entry_dirty_log_msg(void *udata, const H5C_cache_entry_t *entry,
+    herr_t fxn_ret_value)
+{
+    H5C_log_json_udata_t *json_udata = (H5C_log_json_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->message);
+    HDassert(entry);
+
+    /* Create the log message string */
+    HDsnprintf(json_udata->message, H5C_MAX_JSON_LOG_MSG_SIZE, 
+"\
+{\
+\"timestamp\":%lld,\
+\"action\":\"dirty\",\
+\"address\":0x%lx,\
+\"returned\":%d\
+},\n\
+"
+    , (long long)HDtime(NULL), (unsigned long)entry->addr, (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__json_write_log_message(json_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_mark_entry_dirty_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_mark_entry_clean_log_msg
+ *
+ * Purpose:     Write a log message for marking cache entries as clean.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_mark_entry_clean_log_msg(void *udata, const H5C_cache_entry_t *entry,
+    herr_t fxn_ret_value)
+{
+    H5C_log_json_udata_t *json_udata = (H5C_log_json_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->message);
+    HDassert(entry);
+
+    /* Create the log message string */
+    HDsnprintf(json_udata->message, H5C_MAX_JSON_LOG_MSG_SIZE, 
+"\
+{\
+\"timestamp\":%lld,\
+\"action\":\"clean\",\
+\"address\":0x%lx,\
+\"returned\":%d\
+},\n\
+"
+    , (long long)HDtime(NULL), (unsigned long)entry->addr, (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__json_write_log_message(json_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_mark_entry_clean_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_mark_unserialized_entry_log_msg
+ *
+ * Purpose:     Write a log message for marking cache entries as unserialized.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_mark_unserialized_entry_log_msg(void *udata,
+    const H5C_cache_entry_t *entry, herr_t fxn_ret_value)
+{
+    H5C_log_json_udata_t *json_udata = (H5C_log_json_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->message);
+    HDassert(entry);
+
+    /* Create the log message string */
+    HDsnprintf(json_udata->message, H5C_MAX_JSON_LOG_MSG_SIZE, 
+"\
+{\
+\"timestamp\":%lld,\
+\"action\":\"unserialized\",\
+\"address\":0x%lx,\
+\"returned\":%d\
+},\n\
+"
+    , (long long)HDtime(NULL), (unsigned long)entry->addr, (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__json_write_log_message(json_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_mark_unserialized_entry_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_mark_serialize_entry_log_msg
+ *
+ * Purpose:     Write a log message for marking cache entries as serialize.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_mark_serialized_entry_log_msg(void *udata, const H5C_cache_entry_t *entry,
+    herr_t fxn_ret_value)
+{
+    H5C_log_json_udata_t *json_udata = (H5C_log_json_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->message);
+    HDassert(entry);
+
+    /* Create the log message string */
+    HDsnprintf(json_udata->message, H5C_MAX_JSON_LOG_MSG_SIZE, 
+"\
+{\
+\"timestamp\":%lld,\
+\"action\":\"serialized\",\
+\"address\":0x%lx,\
+\"returned\":%d\
+},\n\
+"
+    , (long long)HDtime(NULL), (unsigned long)entry->addr, (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__json_write_log_message(json_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_mark_serialized_entry_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_move_entry_log_msg
+ *
+ * Purpose:     Write a log message for moving a cache entry.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_move_entry_log_msg(void *udata, haddr_t old_addr, haddr_t new_addr,
+    int type_id, herr_t fxn_ret_value)
+{
+    H5C_log_json_udata_t *json_udata = (H5C_log_json_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->message);
+
+    /* Create the log message string */
+    HDsnprintf(json_udata->message, H5C_MAX_JSON_LOG_MSG_SIZE, 
+"\
+{\
+\"timestamp\":%lld,\
+\"action\":\"move\",\
+\"old_address\":0x%lx,\
+\"new_address\":0x%lx,\
+\"type_id\":%d,\
+\"returned\":%d\
+},\n\
+"
+    , (long long)HDtime(NULL), (unsigned long)old_addr, 
+      (unsigned long)new_addr, type_id, (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__json_write_log_message(json_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_move_entry_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_pin_entry_log_msg
+ *
+ * Purpose:     Write a log message for pinning a cache entry.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_pin_entry_log_msg(void *udata, const H5C_cache_entry_t *entry,
+    herr_t fxn_ret_value)
+{
+    H5C_log_json_udata_t *json_udata = (H5C_log_json_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->message);
+    HDassert(entry);
+
+    /* Create the log message string */
+    HDsnprintf(json_udata->message, H5C_MAX_JSON_LOG_MSG_SIZE, 
+"\
+{\
+\"timestamp\":%lld,\
+\"action\":\"pin\",\
+\"address\":0x%lx,\
+\"returned\":%d\
+},\n\
+"
+    , (long long)HDtime(NULL), (unsigned long)entry->addr, 
+      (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__json_write_log_message(json_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_pin_entry_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_create_fd_log_msg
+ *
+ * Purpose:     Write a log message for creating a flush dependency between
+ *              two cache entries.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_create_fd_log_msg(void *udata, const H5C_cache_entry_t *parent,
+    const H5C_cache_entry_t *child, herr_t fxn_ret_value)
+{
+    H5C_log_json_udata_t *json_udata = (H5C_log_json_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->message);
+    HDassert(parent);
+    HDassert(child);
+
+    /* Create the log message string */
+    HDsnprintf(json_udata->message, H5C_MAX_JSON_LOG_MSG_SIZE, 
+"\
+{\
+\"timestamp\":%lld,\
+\"action\":\"create_fd\",\
+\"parent_addr\":0x%lx,\
+\"child_addr\":0x%lx,\
+\"returned\":%d\
+},\n\
+"
+    , (long long)HDtime(NULL), (unsigned long)parent->addr, 
+      (unsigned long)child->addr, (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__json_write_log_message(json_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_create_fd_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_protect_entry_log_msg
+ *
+ * Purpose:     Write a log message for protecting a cache entry.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_protect_entry_log_msg(void *udata, const H5C_cache_entry_t *entry,
+    int type_id, unsigned flags, herr_t fxn_ret_value)
+{
+    H5C_log_json_udata_t *json_udata = (H5C_log_json_udata_t *)(udata);
+    char rw_s[16];
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->message);
+    HDassert(entry);
+
+    if(H5C__READ_ONLY_FLAG == flags)
+        HDstrcpy(rw_s, "READ");
+    else 
+        HDstrcpy(rw_s, "WRITE");
+
+    /* Create the log message string */
+    HDsnprintf(json_udata->message, H5C_MAX_JSON_LOG_MSG_SIZE, 
+"\
+{\
+\"timestamp\":%lld,\
+\"action\":\"protect\",\
+\"address\":0x%lx,\
+\"type_id\":%d,\
+\"readwrite\":\"%s\",\
+\"size\":%d,\
+\"returned\":%d\
+},\n\
+"
+    , (long long)HDtime(NULL), (unsigned long)entry->addr, 
+      type_id, rw_s, (int)entry->size, (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__json_write_log_message(json_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_protect_entry_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_resize_entry_log_msg
+ *
+ * Purpose:     Write a log message for resizing a cache entry.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_resize_entry_log_msg(void *udata, const H5C_cache_entry_t *entry,
+    size_t new_size, herr_t fxn_ret_value)
+{
+    H5C_log_json_udata_t *json_udata = (H5C_log_json_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->message);
+    HDassert(entry);
+
+    /* Create the log message string */
+    HDsnprintf(json_udata->message, H5C_MAX_JSON_LOG_MSG_SIZE, 
+"\
+{\
+\"timestamp\":%lld,\
+\"action\":\"resize\",\
+\"address\":0x%lx,\
+\"new_size\":%d,\
+\"returned\":%d\
+},\n\
+"
+    , (long long)HDtime(NULL), (unsigned long)entry->addr, 
+      (int)new_size, (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__json_write_log_message(json_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_resize_entry_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_unpin_entry_log_msg
+ *
+ * Purpose:     Write a log message for unpinning a cache entry.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_unpin_entry_log_msg(void *udata, const H5C_cache_entry_t *entry,
+    herr_t fxn_ret_value)
+{
+    H5C_log_json_udata_t *json_udata = (H5C_log_json_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->message);
+    HDassert(entry);
+
+    /* Create the log message string */
+    HDsnprintf(json_udata->message, H5C_MAX_JSON_LOG_MSG_SIZE, 
+"\
+{\
+\"timestamp\":%lld,\
+\"action\":\"unpin\",\
+\"address\":0x%lx,\
+\"returned\":%d\
+},\n\
+"
+    , (long long)HDtime(NULL), (unsigned long)entry->addr, 
+      (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__json_write_log_message(json_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_unpin_entry_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_destroy_fd_log_msg
+ *
+ * Purpose:     Write a log message for destroying a flush dependency
+ *              between two cache entries.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_destroy_fd_log_msg(void *udata, const H5C_cache_entry_t *parent,
+    const H5C_cache_entry_t *child, herr_t fxn_ret_value)
+{
+    H5C_log_json_udata_t *json_udata = (H5C_log_json_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->message);
+    HDassert(parent);
+    HDassert(child);
+
+    /* Create the log message string */
+    HDsnprintf(json_udata->message, H5C_MAX_JSON_LOG_MSG_SIZE, 
+"\
+{\
+\"timestamp\":%lld,\
+\"action\":\"destroy_fd\",\
+\"parent_addr\":0x%lx,\
+\"child_addr\":0x%lx,\
+\"returned\":%d\
+},\n\
+"
+    , (long long)HDtime(NULL), (unsigned long)parent->addr, 
+      (unsigned long)child->addr, (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__json_write_log_message(json_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_destroy_fd_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_unprotect_entry_log_msg
+ *
+ * Purpose:     Write a log message for unprotecting a cache entry.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_unprotect_entry_log_msg(void *udata, const H5C_cache_entry_t *entry,
+    int type_id, unsigned flags, herr_t fxn_ret_value)
+{
+    H5C_log_json_udata_t *json_udata = (H5C_log_json_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->message);
+    HDassert(entry);
+
+    /* Create the log message string */
+    HDsnprintf(json_udata->message, H5C_MAX_JSON_LOG_MSG_SIZE, 
+"\
+{\
+\"timestamp\":%lld,\
+\"action\":\"unprotect\",\
+\"address\":0x%lx,\
+\"id\":%d,\
+\"flags\":%x,\
+\"returned\":%d\
+},\n\
+"
+    , (long long)HDtime(NULL), (unsigned long)entry->addr, 
+      type_id, flags, (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__json_write_log_message(json_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_unprotect_entry_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_set_cache_config_log_msg
+ *
+ * Purpose:     Write a log message for setting the cache configuration.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_set_cache_config_log_msg(void *udata, const H5AC_cache_config_t *config,
+    herr_t fxn_ret_value)
+{
+    H5C_log_json_udata_t *json_udata = (H5C_log_json_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->message);
+    HDassert(config);
+
+    /* Create the log message string */
+    HDsnprintf(json_udata->message, H5C_MAX_JSON_LOG_MSG_SIZE, 
+"\
+{\
+\"timestamp\":%lld,\
+\"action\":\"set_config\",\
+\"returned\":%d\
+},\n\
+"
+    , (long long)HDtime(NULL), (int)fxn_ret_value);
+
+
+    /* Write the log message to the file */
+    if(H5C__json_write_log_message(json_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_set_cache_config_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__json_write_remove_entry_log_msg
+ *
+ * Purpose:     Write a log message for removing a cache entry.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__json_write_remove_entry_log_msg(void *udata, const H5C_cache_entry_t *entry,
+    herr_t fxn_ret_value)
+{
+    H5C_log_json_udata_t *json_udata = (H5C_log_json_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(json_udata);
+    HDassert(json_udata->message);
+    HDassert(entry);
+
+    /* Create the log message string */
+    HDsnprintf(json_udata->message, H5C_MAX_JSON_LOG_MSG_SIZE, 
+"\
+{\
+\"timestamp\":%lld,\
+\"action\":\"remove\",\
+\"address\":0x%lx,\
+\"returned\":%d\
+},\n\
+"
+    , (long long)HDtime(NULL), (unsigned long)entry->addr, 
+      (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__json_write_log_message(json_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__json_write_remove_entry_log_msg() */
+
diff --git a/src/H5Clog_trace.c b/src/H5Clog_trace.c
new file mode 100644
index 0000000..f7d6889
--- /dev/null
+++ b/src/H5Clog_trace.c
@@ -0,0 +1,1008 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*-------------------------------------------------------------------------
+ *
+ * Created:     H5Clog_trace.c
+ *
+ * Purpose:     Cache log implementation that emits trace entries intended
+ *              for consumption by a future 'cache replay' feature.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/****************/
+/* Module Setup */
+/****************/
+#include "H5Cmodule.h"         /* This source code file is part of the H5C module */
+
+/***********/
+/* Headers */
+/***********/
+#include "H5private.h"          /* Generic Functions                        */
+#include "H5Cpkg.h"             /* Cache                                    */
+#include "H5Clog.h"             /* Cache logging                            */
+#include "H5Eprivate.h"         /* Error handling                           */
+#include "H5MMprivate.h"        /* Memory management                        */
+
+
+/****************/
+/* Local Macros */
+/****************/
+
+/* Max log message size */
+#define H5C_MAX_TRACE_LOG_MSG_SIZE 2048
+
+
+/******************/
+/* Local Typedefs */
+/******************/
+
+
+/********************/
+/* Package Typedefs */
+/********************/
+
+typedef struct H5C_log_trace_udata_t {
+    FILE *outfile;
+    char *message;
+} H5C_log_trace_udata_t;
+
+
+/********************/
+/* Local Prototypes */
+/********************/
+
+/* Internal message handling calls */
+static herr_t H5C__trace_write_log_message(H5C_log_trace_udata_t *trace_udata);
+
+/* Log message callbacks */
+static herr_t H5C__trace_tear_down_logging(H5C_log_info_t *log_info);
+static herr_t H5C__trace_write_expunge_entry_log_msg(void *udata, haddr_t address, int type_id, herr_t fxn_ret_value);
+static herr_t H5C__trace_write_flush_cache_log_msg(void *udata, herr_t fxn_ret_value);
+static herr_t H5C__trace_write_insert_entry_log_msg(void *udata, haddr_t address, int type_id, unsigned flags, size_t size, herr_t fxn_ret_value);
+static herr_t H5C__trace_write_mark_entry_dirty_log_msg(void *udata, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+static herr_t H5C__trace_write_mark_entry_clean_log_msg(void *udata, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+static herr_t H5C__trace_write_mark_unserialized_entry_log_msg(void *udata, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+static herr_t H5C__trace_write_mark_serialized_entry_log_msg(void *udata, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+static herr_t H5C__trace_write_move_entry_log_msg(void *udata, haddr_t old_addr, haddr_t new_addr, int type_id, herr_t fxn_ret_value);
+static herr_t H5C__trace_write_pin_entry_log_msg(void *udata, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+static herr_t H5C__trace_write_create_fd_log_msg(void *udata, const H5C_cache_entry_t *parent, const H5C_cache_entry_t *child, herr_t fxn_ret_value);
+static herr_t H5C__trace_write_protect_entry_log_msg(void *udata, const H5C_cache_entry_t *entry, int type_id, unsigned flags, herr_t fxn_ret_value);
+static herr_t H5C__trace_write_resize_entry_log_msg(void *udata, const H5C_cache_entry_t *entry, size_t new_size, herr_t fxn_ret_value);
+static herr_t H5C__trace_write_unpin_entry_log_msg(void *udata, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+static herr_t H5C__trace_write_destroy_fd_log_msg(void *udata, const H5C_cache_entry_t *parent, const H5C_cache_entry_t *child, herr_t fxn_ret_value);
+static herr_t H5C__trace_write_unprotect_entry_log_msg(void *udata, const H5C_cache_entry_t *entry, int type_id, unsigned flags, herr_t fxn_ret_value);
+static herr_t H5C__trace_write_set_cache_config_log_msg(void *udata, const H5AC_cache_config_t *config, herr_t fxn_ret_value);
+static herr_t H5C__trace_write_remove_entry_log_msg(void *udata, const H5C_cache_entry_t *entry, herr_t fxn_ret_value);
+
+
+/*********************/
+/* Package Variables */
+/*********************/
+
+
+/*****************************/
+/* Library Private Variables */
+/*****************************/
+
+
+/*******************/
+/* Local Variables */
+/*******************/
+
+/* Note that there's no cache set up call since that's the
+ * place where this struct is wired into the cache.
+ */
+static H5C_log_class_t H5C_trace_log_class_g = {
+    "trace",
+    H5C__trace_tear_down_logging,
+    NULL,                               /* start logging */
+    NULL,                               /* stop logging */
+    NULL,                               /* write start message */
+    NULL,                               /* write stop message */
+    NULL,                               /* write create cache message */
+    NULL,                               /* write destroy cache message */
+    NULL,                               /* write evict cache message */
+    H5C__trace_write_expunge_entry_log_msg,
+    H5C__trace_write_flush_cache_log_msg,
+    H5C__trace_write_insert_entry_log_msg,
+    H5C__trace_write_mark_entry_dirty_log_msg,
+    H5C__trace_write_mark_entry_clean_log_msg,
+    H5C__trace_write_mark_unserialized_entry_log_msg,
+    H5C__trace_write_mark_serialized_entry_log_msg,
+    H5C__trace_write_move_entry_log_msg,
+    H5C__trace_write_pin_entry_log_msg,
+    H5C__trace_write_create_fd_log_msg,
+    H5C__trace_write_protect_entry_log_msg,
+    H5C__trace_write_resize_entry_log_msg,
+    H5C__trace_write_unpin_entry_log_msg,
+    H5C__trace_write_destroy_fd_log_msg,
+    H5C__trace_write_unprotect_entry_log_msg,
+    H5C__trace_write_set_cache_config_log_msg,
+    H5C__trace_write_remove_entry_log_msg
+};
+
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__trace_write_log_message
+ *
+ * Purpose:     Write a message to the log file and flush the file. 
+ *              The message string is neither modified nor freed.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__trace_write_log_message(H5C_log_trace_udata_t *trace_udata)
+{
+    size_t n_chars;
+    herr_t ret_value = SUCCEED;      /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(trace_udata);
+    HDassert(trace_udata->outfile);
+    HDassert(trace_udata->message);
+
+    /* Write the log message and flush */
+    n_chars = HDstrlen(trace_udata->message);
+    if((int)n_chars != HDfprintf(trace_udata->outfile, trace_udata->message))
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "error writing log message")
+    HDmemset((void *)(trace_udata->message), 0, (size_t)(n_chars * sizeof(char)));
+            
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__trace_write_log_message() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C_log_trace_set_up
+ *
+ * Purpose:     Setup for metadata cache logging.
+ *
+ *              Metadata logging is enabled and disabled at two levels. This
+ *              function and the associated tear_down function open and close
+ *              the log file. the start_ and stop_logging functions are then
+ *              used to switch logging on/off. Optionally, logging can begin
+ *              as soon as the log file is opened (set via the start_immediately
+ *              parameter to this function).
+ *
+ *              The log functionality is split between the H5C and H5AC
+ *              packages. Log state and direct log manipulation resides in
+ *              H5C. Log messages are generated in H5AC and sent to
+ *              the H5C__trace_write_log_message function.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_log_trace_set_up(H5C_log_info_t *log_info, const char log_location[], int mpi_rank)
+{
+    H5C_log_trace_udata_t *trace_udata = NULL;
+    char *file_name = NULL;
+    size_t n_chars;
+    herr_t ret_value = SUCCEED;      /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(log_info);
+    HDassert(log_location);
+
+    /* Set up the class struct */
+    log_info->cls = &H5C_trace_log_class_g;
+
+    /* Allocate memory for the JSON-specific data */
+    if(NULL == (log_info->udata = H5MM_calloc(sizeof(H5C_log_trace_udata_t))))
+        HGOTO_ERROR(H5E_CACHE, H5E_CANTALLOC, FAIL, "memory allocation failed")
+    trace_udata = (H5C_log_trace_udata_t *)(log_info->udata);
+    
+    /* Allocate memory for the message buffer */
+    if(NULL == (trace_udata->message = (char *)H5MM_calloc(H5C_MAX_TRACE_LOG_MSG_SIZE * sizeof(char))))
+        HGOTO_ERROR(H5E_CACHE, H5E_CANTALLOC, FAIL, "memory allocation failed")
+
+    /* Possibly fix up the log file name.
+     * The extra 39 characters are for adding the rank to the file name
+     * under parallel HDF5. 39 characters allows > 2^127 processes which
+     * should be enough for anybody.
+     *
+     * allocation size = <path length> + dot + <rank # length> + \0
+     */
+    n_chars = HDstrlen(log_location) + 1 + 39 + 1;
+    if(NULL == (file_name = (char *)H5MM_calloc(n_chars * sizeof(char))))
+        HGOTO_ERROR(H5E_CACHE, H5E_CANTALLOC, FAIL, "can't allocate memory for mdc log file name manipulation")
+
+    /* Add the rank to the log file name when MPI is in use */
+    if(-1 == mpi_rank)
+        HDsnprintf(file_name, n_chars, "%s", log_location);
+    else
+        HDsnprintf(file_name, n_chars, "%s.%d", log_location, mpi_rank);
+
+    /* Open log file and set it to be unbuffered */
+    if(NULL == (trace_udata->outfile = HDfopen(file_name, "w")))
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "can't create mdc log file")
+    HDsetbuf(trace_udata->outfile, NULL);
+
+    /* Write the header */
+    HDfprintf(trace_udata->outfile, "### HDF5 metadata cache trace file version 1 ###\n");
+
+ done:
+    if(file_name)
+        H5MM_xfree(file_name);
+
+    /* Free and reset the log info struct on errors */
+    if(FAIL == ret_value) {
+        /* Free */
+        if(trace_udata && trace_udata->message)
+            H5MM_xfree(trace_udata->message);
+        if(trace_udata)
+            H5MM_xfree(trace_udata);
+
+        /* Reset */
+        log_info->udata = NULL;
+        log_info->cls = NULL;
+    }
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_log_trace_set_up() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__trace_tear_down_logging
+ *
+ * Purpose:     Tear-down for metadata cache logging.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__trace_tear_down_logging(H5C_log_info_t *log_info)
+{
+    H5C_log_trace_udata_t *trace_udata = NULL;
+    herr_t ret_value = SUCCEED;      /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(log_info);
+
+    /* Alias */
+    trace_udata = (H5C_log_trace_udata_t *)(log_info->udata);
+
+    /* Free the message buffer */
+    H5MM_xfree(trace_udata->message);
+
+    /* Close log file */
+    if(EOF == HDfclose(trace_udata->outfile))
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "problem closing mdc log file")
+    trace_udata->outfile = NULL;
+
+    /* Fre the udata */
+    H5MM_xfree(trace_udata);
+
+    /* Reset the log class info and udata */
+    log_info->cls = NULL;
+    log_info->udata = NULL;
+
+ done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__trace_tear_down_logging() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__trace_write_expunge_entry_log_msg
+ *
+ * Purpose:     Write a log message for expunge of cache entries.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__trace_write_expunge_entry_log_msg(void *udata, haddr_t address,
+    int type_id, herr_t fxn_ret_value)
+{
+    H5C_log_trace_udata_t *trace_udata = (H5C_log_trace_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(trace_udata);
+    HDassert(trace_udata->message);
+
+    /* Create the log message string */
+    HDsnprintf(trace_udata->message, H5C_MAX_TRACE_LOG_MSG_SIZE, "H5AC_expunge_entry 0x%lx %d %d\n", 
+            (unsigned long)address, type_id, (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__trace_write_log_message(trace_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__trace_write_expunge_entry_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__trace_write_flush_cache_log_msg
+ *
+ * Purpose:     Write a log message for cache flushes.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__trace_write_flush_cache_log_msg(void *udata, herr_t fxn_ret_value)
+{
+    H5C_log_trace_udata_t *trace_udata = (H5C_log_trace_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(trace_udata);
+    HDassert(trace_udata->message);
+
+    /* Create the log message string */
+    HDsnprintf(trace_udata->message, H5C_MAX_TRACE_LOG_MSG_SIZE, "H5AC_flush %d\n", 
+            (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__trace_write_log_message(trace_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__trace_write_flush_cache_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__trace_write_insert_entry_log_msg
+ *
+ * Purpose:     Write a log message for insertion of cache entries.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__trace_write_insert_entry_log_msg(void *udata, haddr_t address,
+    int type_id, unsigned flags, size_t size, herr_t fxn_ret_value)
+{
+    H5C_log_trace_udata_t *trace_udata = (H5C_log_trace_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(trace_udata);
+    HDassert(trace_udata->message);
+
+    /* Create the log message string */
+    HDsnprintf(trace_udata->message, H5C_MAX_TRACE_LOG_MSG_SIZE, "H5AC_insert_entry 0x%lx %d 0x%x %d %d\n", 
+            (unsigned long)address, type_id, flags, (int)size, (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__trace_write_log_message(trace_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__trace_write_insert_entry_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__trace_write_mark_entry_dirty_log_msg
+ *
+ * Purpose:     Write a log message for marking cache entries as dirty.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__trace_write_mark_entry_dirty_log_msg(void *udata, const H5C_cache_entry_t *entry,
+    herr_t fxn_ret_value)
+{
+    H5C_log_trace_udata_t *trace_udata = (H5C_log_trace_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(trace_udata);
+    HDassert(trace_udata->message);
+    HDassert(entry);
+
+    /* Create the log message string */
+    HDsnprintf(trace_udata->message, H5C_MAX_TRACE_LOG_MSG_SIZE, "H5AC_mark_entry_dirty 0x%lx %d\n", 
+            (unsigned long)(entry->addr), (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__trace_write_log_message(trace_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__trace_write_mark_entry_dirty_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__trace_write_mark_entry_clean_log_msg
+ *
+ * Purpose:     Write a log message for marking cache entries as clean.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__trace_write_mark_entry_clean_log_msg(void *udata, const H5C_cache_entry_t *entry,
+    herr_t fxn_ret_value)
+{
+    H5C_log_trace_udata_t *trace_udata = (H5C_log_trace_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(trace_udata);
+    HDassert(trace_udata->message);
+    HDassert(entry);
+
+    /* Create the log message string */
+    HDsnprintf(trace_udata->message, H5C_MAX_TRACE_LOG_MSG_SIZE, "H5AC_mark_entry_clean 0x%lx %d\n", 
+            (unsigned long)(entry->addr), (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__trace_write_log_message(trace_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__trace_write_mark_entry_clean_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__trace_write_mark_unserialized_entry_log_msg
+ *
+ * Purpose:     Write a log message for marking cache entries as unserialized.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__trace_write_mark_unserialized_entry_log_msg(void *udata,
+    const H5C_cache_entry_t *entry, herr_t fxn_ret_value)
+{
+    H5C_log_trace_udata_t *trace_udata = (H5C_log_trace_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(trace_udata);
+    HDassert(trace_udata->message);
+    HDassert(entry);
+
+    /* Create the log message string */
+    HDsnprintf(trace_udata->message, H5C_MAX_TRACE_LOG_MSG_SIZE, "H5AC_mark_entry_unserialized 0x%lx %d\n", 
+            (unsigned long)(entry->addr), (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__trace_write_log_message(trace_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__trace_write_mark_unserialized_entry_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__trace_write_mark_serialized_entry_log_msg
+ *
+ * Purpose:     Write a log message for marking cache entries as serialize.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__trace_write_mark_serialized_entry_log_msg(void *udata, const H5C_cache_entry_t *entry,
+    herr_t fxn_ret_value)
+{
+    H5C_log_trace_udata_t *trace_udata = (H5C_log_trace_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(trace_udata);
+    HDassert(trace_udata->message);
+    HDassert(entry);
+
+    /* Create the log message string */
+    HDsnprintf(trace_udata->message, H5C_MAX_TRACE_LOG_MSG_SIZE, "H5AC_mark_entry_serialized 0x%lx %d\n", 
+            (unsigned long)(entry->addr), (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__trace_write_log_message(trace_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__trace_write_mark_serialized_entry_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__trace_write_move_entry_log_msg
+ *
+ * Purpose:     Write a log message for moving a cache entry.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__trace_write_move_entry_log_msg(void *udata, haddr_t old_addr, haddr_t new_addr,
+    int type_id, herr_t fxn_ret_value)
+{
+    H5C_log_trace_udata_t *trace_udata = (H5C_log_trace_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(trace_udata);
+    HDassert(trace_udata->message);
+
+    /* Create the log message string */
+    HDsnprintf(trace_udata->message, H5C_MAX_TRACE_LOG_MSG_SIZE, "H5AC_move_entry 0x%lx 0x%lx %d %d\n", 
+            (unsigned long)old_addr, (unsigned long)new_addr, type_id, (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__trace_write_log_message(trace_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__trace_write_move_entry_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__trace_write_pin_entry_log_msg
+ *
+ * Purpose:     Write a log message for pinning a cache entry.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__trace_write_pin_entry_log_msg(void *udata, const H5C_cache_entry_t *entry,
+    herr_t fxn_ret_value)
+{
+    H5C_log_trace_udata_t *trace_udata = (H5C_log_trace_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(trace_udata);
+    HDassert(trace_udata->message);
+    HDassert(entry);
+
+    /* Create the log message string */
+    HDsnprintf(trace_udata->message, H5C_MAX_TRACE_LOG_MSG_SIZE, "H5AC_pin_protected_entry 0x%lx %d\n", 
+            (unsigned long)(entry->addr), (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__trace_write_log_message(trace_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__trace_write_pin_entry_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__trace_write_create_fd_log_msg
+ *
+ * Purpose:     Write a log message for creating a flush dependency between
+ *              two cache entries.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__trace_write_create_fd_log_msg(void *udata, const H5C_cache_entry_t *parent,
+    const H5C_cache_entry_t *child, herr_t fxn_ret_value)
+{
+    H5C_log_trace_udata_t *trace_udata = (H5C_log_trace_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(trace_udata);
+    HDassert(trace_udata->message);
+    HDassert(parent);
+    HDassert(child);
+
+    /* Create the log message string */
+    HDsnprintf(trace_udata->message, H5C_MAX_TRACE_LOG_MSG_SIZE, "H5AC_create_flush_dependency 0x%lx 0x%lx %d\n", 
+            (unsigned long)(parent->addr), (unsigned long)(child->addr), (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__trace_write_log_message(trace_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__trace_write_create_fd_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__trace_write_protect_entry_log_msg
+ *
+ * Purpose:     Write a log message for protecting a cache entry.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__trace_write_protect_entry_log_msg(void *udata, const H5C_cache_entry_t *entry,
+    int type_id, unsigned flags, herr_t fxn_ret_value)
+{
+    H5C_log_trace_udata_t *trace_udata = (H5C_log_trace_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(trace_udata);
+    HDassert(trace_udata->message);
+    HDassert(entry);
+
+    /* Create the log message string */
+    HDsnprintf(trace_udata->message, H5C_MAX_TRACE_LOG_MSG_SIZE, "H5AC_protect 0x%lx %d 0x%x %d %d\n", 
+            (unsigned long)(entry->addr), type_id, flags, (int)(entry->size), (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__trace_write_log_message(trace_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__trace_write_protect_entry_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__trace_write_resize_entry_log_msg
+ *
+ * Purpose:     Write a log message for resizing a cache entry.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__trace_write_resize_entry_log_msg(void *udata, const H5C_cache_entry_t *entry,
+    size_t new_size, herr_t fxn_ret_value)
+{
+    H5C_log_trace_udata_t *trace_udata = (H5C_log_trace_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(trace_udata);
+    HDassert(trace_udata->message);
+    HDassert(entry);
+
+    /* Create the log message string */
+    HDsnprintf(trace_udata->message, H5C_MAX_TRACE_LOG_MSG_SIZE, "H5AC_resize_entry 0x%lx %d %d\n", 
+            (unsigned long)(entry->addr), (int)new_size, (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__trace_write_log_message(trace_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__trace_write_resize_entry_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__trace_write_unpin_entry_log_msg
+ *
+ * Purpose:     Write a log message for unpinning a cache entry.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__trace_write_unpin_entry_log_msg(void *udata, const H5C_cache_entry_t *entry,
+    herr_t fxn_ret_value)
+{
+    H5C_log_trace_udata_t *trace_udata = (H5C_log_trace_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(trace_udata);
+    HDassert(trace_udata->message);
+    HDassert(entry);
+
+    /* Create the log message string */
+    HDsnprintf(trace_udata->message, H5C_MAX_TRACE_LOG_MSG_SIZE, "H5AC_unpin_entry 0x%lx %d\n", 
+            (unsigned long)(entry->addr), (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__trace_write_log_message(trace_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__trace_write_unpin_entry_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__trace_write_destroy_fd_log_msg
+ *
+ * Purpose:     Write a log message for destroying a flush dependency
+ *              between two cache entries.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__trace_write_destroy_fd_log_msg(void *udata, const H5C_cache_entry_t *parent,
+    const H5C_cache_entry_t *child, herr_t fxn_ret_value)
+{
+    H5C_log_trace_udata_t *trace_udata = (H5C_log_trace_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(trace_udata);
+    HDassert(trace_udata->message);
+    HDassert(parent);
+    HDassert(child);
+
+    /* Create the log message string */
+    HDsnprintf(trace_udata->message, H5C_MAX_TRACE_LOG_MSG_SIZE, "H5AC_destroy_flush_dependency 0x%lx 0x%lx %d\n", 
+            (unsigned long)(parent->addr), (unsigned long)(child->addr), (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__trace_write_log_message(trace_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__trace_write_destroy_fd_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__trace_write_unprotect_entry_log_msg
+ *
+ * Purpose:     Write a log message for unprotecting a cache entry.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__trace_write_unprotect_entry_log_msg(void *udata, const H5C_cache_entry_t *entry,
+    int type_id, unsigned flags, herr_t fxn_ret_value)
+{
+    H5C_log_trace_udata_t *trace_udata = (H5C_log_trace_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(trace_udata);
+    HDassert(trace_udata->message);
+    HDassert(entry);
+
+    /* Create the log message string */
+    HDsnprintf(trace_udata->message, H5C_MAX_TRACE_LOG_MSG_SIZE, "H5AC_unprotect 0x%lx %d 0x%x %d\n", 
+            (unsigned long)(entry->addr), type_id, flags, (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__trace_write_log_message(trace_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__trace_write_unprotect_entry_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__trace_write_set_cache_config_log_msg
+ *
+ * Purpose:     Write a log message for setting the cache configuration.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__trace_write_set_cache_config_log_msg(void *udata, const H5AC_cache_config_t *config,
+    herr_t fxn_ret_value)
+{
+    H5C_log_trace_udata_t *trace_udata = (H5C_log_trace_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(trace_udata);
+    HDassert(trace_udata->message);
+    HDassert(config);
+
+    /* Create the log message string */
+    HDsnprintf(trace_udata->message, H5C_MAX_TRACE_LOG_MSG_SIZE,
+            "H5AC_set_cache_auto_resize_config %d %d %d %d \"%s\" %d %d %d %f %d %d %ld %d %f %f %d %f %f %d %d %d %f %f %d %d %d %d %f %zu %d %d\n",
+            config->version,
+            (int)(config->rpt_fcn_enabled),
+            (int)(config->open_trace_file),
+            (int)(config->close_trace_file),
+            config->trace_file_name,
+            (int)(config->evictions_enabled),
+            (int)(config->set_initial_size),
+            (int)(config->initial_size),
+            config->min_clean_fraction,
+            (int)(config->max_size),
+            (int)(config->min_size),
+            config->epoch_length,
+            (int)(config->incr_mode),
+            config->lower_hr_threshold,
+            config->increment,
+            (int)(config->flash_incr_mode),
+            config->flash_multiple,
+            config->flash_threshold,
+            (int)(config->apply_max_increment),
+            (int)(config->max_increment),
+            (int)(config->decr_mode),
+            config->upper_hr_threshold,
+            config->decrement,
+            (int)(config->apply_max_decrement),
+            (int)(config->max_decrement),
+            config->epochs_before_eviction,
+            (int)(config->apply_empty_reserve),
+            config->empty_reserve,
+            config->dirty_bytes_threshold,
+            config->metadata_write_strategy,
+            (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__trace_write_log_message(trace_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__trace_write_set_cache_config_log_msg() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__trace_write_remove_entry_log_msg
+ *
+ * Purpose:     Write a log message for removing a cache entry.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Dana Robinson
+ *              Fall 2018
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__trace_write_remove_entry_log_msg(void *udata, const H5C_cache_entry_t *entry,
+    herr_t fxn_ret_value)
+{
+    H5C_log_trace_udata_t *trace_udata = (H5C_log_trace_udata_t *)(udata);
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(trace_udata);
+    HDassert(trace_udata->message);
+    HDassert(entry);
+
+    /* Create the log message string */
+    HDsnprintf(trace_udata->message, H5C_MAX_TRACE_LOG_MSG_SIZE, "H5AC_remove_entry 0x%lx %d\n", 
+            (unsigned long)(entry->addr), (int)fxn_ret_value);
+
+    /* Write the log message to the file */
+    if(H5C__trace_write_log_message(trace_udata) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_LOGGING, FAIL, "unable to emit log message")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__trace_write_remove_entry_log_msg() */
+
diff --git a/src/H5Cpkg.h b/src/H5Cpkg.h
index 98d7a01..9201afb 100644
--- a/src/H5Cpkg.h
+++ b/src/H5Cpkg.h
@@ -37,6 +37,7 @@
 #include "H5Cprivate.h"
 
 /* Other private headers needed by this file */
+#include "H5Clog.h"             /* Cache logging */
 #include "H5SLprivate.h"        /* Skip lists */
 
 /**************************/
@@ -3497,40 +3498,8 @@ typedef struct H5C_tag_info_t {
  * flush_in_progress: Boolean flag indicating whether a flush is in
  * 		progress.
  *
- * trace_file_ptr:  File pointer pointing to the trace file, which is used
- *              to record cache operations for use in simulations and design
- *              studies.  This field will usually be NULL, indicating that
- *              no trace file should be recorded.
- *
- *              Since much of the code supporting the parallel metadata
- *              cache is in H5AC, we don't write the trace file from
- *              H5C.  Instead, H5AC reads the trace_file_ptr as needed.
- *
- *              When we get to using H5C in other places, we may add
- *              code to write trace file data at the H5C level as well.
- *
- * logging_enabled: Boolean flag indicating whether cache logging
- *              which is used to record cache operations for use in
- *              debugging and performance analysis. When this flag is set
- *              to TRUE, it means that the log file is open and ready to
- *              receive log entries. It does NOT mean that cache operations
- *              are currently being recorded. That is controlled by the
- *              currently_logging flag (below).
- *
- *              Since much of the code supporting the parallel metadata
- *              cache is in H5AC, we don't write the trace file from
- *              H5C.  Instead, H5AC reads the trace_file_ptr as needed.
- *
- *              When we get to using H5C in other places, we may add
- *              code to write trace file data at the H5C level as well.
- *
- * currently_logging: Boolean flag that indicates if cache operations are
- *              currently being logged. This flag is flipped by the
- *              H5Fstart/stop_mdc_logging functions.
- *
- * log_file_ptr:  File pointer pointing to the log file. The I/O functions
- *              in stdio.h are used to write to the log file regardless of
- *              the VFD selected.
+ * log_info:    Information used by the MDC logging functionality.
+ *              Described in H5Clog.h.
  *
  * aux_ptr:	Pointer to void used to allow wrapper code to associate
  *		its data with an instance of H5C_t.  The H5C cache code
@@ -4676,10 +4645,7 @@ typedef struct H5C_tag_info_t {
 struct H5C_t {
     uint32_t			magic;
     hbool_t			flush_in_progress;
-    FILE *			trace_file_ptr;
-    hbool_t                     logging_enabled;
-    hbool_t                     currently_logging;
-    FILE *			log_file_ptr;
+    H5C_log_info_t  *log_info;
     void *			aux_ptr;
     int32_t			max_type_id;
     const H5C_class_t * const   *class_table_ptr;
diff --git a/src/H5Cprivate.h b/src/H5Cprivate.h
index 38a86ee..c39c1df 100644
--- a/src/H5Cprivate.h
+++ b/src/H5Cprivate.h
@@ -2219,6 +2219,12 @@ typedef struct H5C_cache_image_ctl_t {
     unsigned				flags;
 } H5C_cache_image_ctl_t;
 
+/* The cache logging output style */
+typedef enum H5C_log_style_t {
+    H5C_LOG_STYLE_JSON,
+    H5C_LOG_STYLE_TRACE
+} H5C_log_style_t;
+
 /***************************************/
 /* Library-private Function Prototypes */
 /***************************************/
@@ -2227,13 +2233,6 @@ H5_DLL H5C_t *H5C_create(size_t max_cache_size, size_t min_clean_size,
     int max_type_id, const H5C_class_t * const *class_table_ptr,
     H5C_write_permitted_func_t check_write_permitted, hbool_t write_permitted,
     H5C_log_flush_func_t log_flush, void *aux_ptr);
-H5_DLL herr_t H5C_set_up_logging(H5C_t *cache_ptr, const char log_location[], hbool_t start_immediately);
-H5_DLL herr_t H5C_tear_down_logging(H5C_t *cache_ptr);
-H5_DLL herr_t H5C_start_logging(H5C_t *cache_ptr);
-H5_DLL herr_t H5C_stop_logging(H5C_t *cache_ptr);
-H5_DLL herr_t H5C_get_logging_status(const H5C_t *cache_ptr, /*OUT*/ hbool_t *is_enabled,
-    /*OUT*/ hbool_t *is_currently_logging);
-H5_DLL herr_t H5C_write_log_message(const H5C_t *cache_ptr, const char message[]);
 H5_DLL void H5C_def_auto_resize_rpt_fcn(H5C_t *cache_ptr, int32_t version,
     double hit_rate, enum H5C_resize_status status,
     size_t old_max_cache_size, size_t new_max_cache_size,
@@ -2267,8 +2266,6 @@ H5_DLL herr_t H5C_get_entry_status(const H5F_t *f, haddr_t addr,
     hbool_t *image_up_to_date_ptr);
 H5_DLL herr_t H5C_get_evictions_enabled(const H5C_t *cache_ptr, hbool_t *evictions_enabled_ptr);
 H5_DLL void * H5C_get_aux_ptr(const H5C_t *cache_ptr);
-H5_DLL FILE *H5C_get_trace_file_ptr(const H5C_t *cache_ptr);
-H5_DLL FILE *H5C_get_trace_file_ptr_from_entry(const H5C_cache_entry_t *entry_ptr);
 H5_DLL herr_t H5C_image_stats(H5C_t * cache_ptr, hbool_t print_header);
 H5_DLL herr_t H5C_insert_entry(H5F_t *f, const H5C_class_t *type, haddr_t addr,
     void *thing, unsigned int flags);
@@ -2292,7 +2289,6 @@ H5_DLL herr_t H5C_set_cache_image_config(const H5F_t *f, H5C_t *cache_ptr,
     H5C_cache_image_ctl_t *config_ptr);
 H5_DLL herr_t H5C_set_evictions_enabled(H5C_t *cache_ptr, hbool_t evictions_enabled);
 H5_DLL herr_t H5C_set_prefix(H5C_t *cache_ptr, char *prefix);
-H5_DLL herr_t H5C_set_trace_file_ptr(H5C_t *cache_ptr, FILE *trace_file_ptr);
 H5_DLL herr_t H5C_stats(H5C_t *cache_ptr, const char *cache_name,
     hbool_t display_detailed_stats);
 H5_DLL void H5C_stats__reset(H5C_t *cache_ptr);
@@ -2316,6 +2312,11 @@ H5_DLL herr_t H5C_cache_image_status(H5F_t * f, hbool_t *load_ci_ptr,
 H5_DLL hbool_t H5C_cache_image_pending(const H5C_t *cache_ptr);
 H5_DLL herr_t H5C_get_mdc_image_info(H5C_t *cache_ptr, haddr_t *image_addr, hsize_t *image_len);
 
+/* Logging functions */
+H5_DLL herr_t H5C_start_logging(H5C_t *cache);
+H5_DLL herr_t H5C_stop_logging(H5C_t *cache);
+H5_DLL herr_t H5C_get_logging_status(const H5C_t *cache, /*OUT*/ hbool_t *is_enabled, /*OUT*/ hbool_t *is_currently_logging);
+
 #ifdef H5_HAVE_PARALLEL
 H5_DLL herr_t H5C_apply_candidate_list(H5F_t *f, H5C_t *cache_ptr,
     unsigned num_candidates, haddr_t *candidates_list_ptr, int mpi_rank,
diff --git a/src/H5Cquery.c b/src/H5Cquery.c
index e4f3133..51ce1c2 100644
--- a/src/H5Cquery.c
+++ b/src/H5Cquery.c
@@ -351,64 +351,6 @@ H5C_get_aux_ptr(const H5C_t *cache_ptr)
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5C_get_trace_file_ptr
- *
- * Purpose:     Get the trace_file_ptr field from the cache.
- *
- *              This field will either be NULL (which indicates that trace
- *              file logging is turned off), or contain a pointer to the
- *              open file to which trace file data is to be written.
- *
- * Return:      Non-NULL trace file pointer (can't fail)
- *
- * Programmer:  John Mainzer
- *              1/20/06
- *
- *-------------------------------------------------------------------------
- */
-FILE *
-H5C_get_trace_file_ptr(const H5C_t *cache_ptr)
-{
-    FUNC_ENTER_NOAPI_NOERR
-
-    /* Check arguments */
-    HDassert(cache_ptr);
-    HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC);
-
-    FUNC_LEAVE_NOAPI(cache_ptr->trace_file_ptr)
-} /* H5C_get_trace_file_ptr() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5C_get_trace_file_ptr_from_entry
- *
- * Purpose:     Get the trace_file_ptr field from the cache, via an entry.
- *
- *              This field will either be NULL (which indicates that trace
- *              file logging is turned off), or contain a pointer to the
- *              open file to which trace file data is to be written.
- *
- * Return:      Non-NULL trace file pointer (can't fail)
- *
- * Programmer:  Quincey Koziol
- *              6/9/08
- *
- *-------------------------------------------------------------------------
- */
-FILE *
-H5C_get_trace_file_ptr_from_entry(const H5C_cache_entry_t *entry_ptr)
-{
-    FUNC_ENTER_NOAPI_NOERR
-
-    /* Sanity checks */
-    HDassert(entry_ptr);
-    HDassert(entry_ptr->cache_ptr);
-
-    FUNC_LEAVE_NOAPI(H5C_get_trace_file_ptr(entry_ptr->cache_ptr))
-} /* H5C_get_trace_file_ptr_from_entry() */
-
-
-/*-------------------------------------------------------------------------
  * Function:    H5C_get_entry_ring
  *
  * Purpose:     Given a file address, retrieve the ring for an entry at that
diff --git a/src/H5D.c b/src/H5D.c
index db70847..fc350f2 100644
--- a/src/H5D.c
+++ b/src/H5D.c
@@ -29,6 +29,8 @@
 #include "H5Iprivate.h"         /* IDs                                      */
 #include "H5VLprivate.h"        /* Virtual Object Layer                     */
 
+#include "H5VLnative_private.h" /* Native VOL connector                     */
+
 
 /****************/
 /* Local Macros */
diff --git a/src/H5Dint.c b/src/H5Dint.c
index 6bb3343..7eb1aaf 100644
--- a/src/H5Dint.c
+++ b/src/H5Dint.c
@@ -25,6 +25,7 @@
 #include "H5CXprivate.h"        /* API Contexts                             */
 #include "H5Dpkg.h"             /* Datasets                                 */
 #include "H5Eprivate.h"         /* Error handling                           */
+#include "H5Fprivate.h"         /* Files                                    */
 #include "H5FLprivate.h"        /* Free Lists                               */
 #include "H5FOprivate.h"        /* File objects                             */
 #include "H5Iprivate.h"         /* IDs                                      */
@@ -59,6 +60,9 @@ static herr_t H5D__init_storage(const H5D_io_info_t *io_info, hbool_t full_overw
         hsize_t old_dim[]);
 static herr_t H5D__append_flush_setup(H5D_t *dset, hid_t dapl_id);
 static herr_t H5D__close_cb(H5VL_object_t *dset_vol_obj);
+static herr_t H5D__use_minimized_dset_headers(H5F_t *file, H5D_t *dset, hbool_t *minimize);
+static herr_t H5D__prepare_minimized_oh(H5F_t *file, H5D_t *dset, H5O_loc_t *oloc);
+static size_t H5D__calculate_minimum_header_size(H5F_t *file, H5D_t *dset, H5O_t *ohdr);
 
 
 /*********************/
@@ -658,6 +662,211 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:   H5D__use_minimized_dset_headers
+ *
+ * Purpose:    Compartmentalize check for file- or dcpl-set values indicating
+ *             to create a "minimized" dataset object header.
+ *             Upon success, write resulting value to out pointer `minimize`.
+ *
+ * Return:     Success: SUCCEED (0) (non-negative value)
+ *             Failure: FAIL (-1) (negative value)
+ *
+ * Programmer: Jacob Smith
+ *             16 August 2018
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D__use_minimized_dset_headers(H5F_t *file, H5D_t *dset, hbool_t *minimize)
+{
+    H5P_genplist_t *plist     = NULL;
+    herr_t          ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI_NOINIT;
+
+    HDassert(file);
+    HDassert(dset);
+    HDassert(minimize);
+
+    plist = H5P_object_verify(dset->shared->dcpl_id, H5P_DATASET_CREATE);
+    if(NULL == plist)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "problem getting dcpl")
+    if(H5P_get(plist, H5D_CRT_MIN_DSET_HDR_SIZE_NAME, minimize) == FAIL)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get minimize value from dcpl")
+
+    if(FALSE == *minimize)
+        *minimize = H5F_get_min_dset_ohdr(file);
+
+done:
+    if(FAIL == ret_value)
+        *minimize = FALSE;
+    FUNC_LEAVE_NOAPI(ret_value);
+} /* H5D__use_minimized_dset_headers */
+
+
+/*-------------------------------------------------------------------------
+ * Function:   H5D__calculate_minimium_header_size
+ *
+ * Purpose:    Calculate the size required for the minimized object header.
+ *
+ * Return:     Success: Positive value > 0
+ *             Failure: 0
+ *
+ * Programmer: Jacob Smith
+ *             16 August 2018
+ *-------------------------------------------------------------------------
+ */
+static size_t
+H5D__calculate_minimum_header_size(H5F_t *file, H5D_t *dset, H5O_t *ohdr)
+{
+    H5T_t      *type             = NULL;
+    H5O_fill_t *fill_prop        = NULL;
+    hbool_t     use_at_least_v18 = FALSE;
+    const char  continuation[1]  = ""; /* requred for work-around */
+    size_t      get_value        = 0;
+    size_t      ret_value        = 0;
+
+    FUNC_ENTER_NOAPI_NOINIT;
+
+    HDassert(file);
+    HDassert(dset);
+    HDassert(ohdr);
+
+    type = dset->shared->type;
+    fill_prop = &(dset->shared->dcpl_cache.fill);
+    use_at_least_v18 = (H5F_LOW_BOUND(file) >= H5F_LIBVER_V18);
+
+    /* Datatype message size */
+    get_value = H5O_msg_size_oh(file, ohdr, H5O_DTYPE_ID, type, 0);
+    if (get_value == 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, 0, "Can't get size of datatype message")
+    ret_value += get_value;
+
+    /* Shared Dataspace message size */
+    get_value = H5O_msg_size_oh(file, ohdr, H5O_SDSPACE_ID, dset->shared->space, 0);
+    if (get_value == 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, 0, "can't get size of dataspace message")
+    ret_value += get_value;
+
+    /* "Layout" message size */
+    get_value = H5O_msg_size_oh(file, ohdr, H5O_LAYOUT_ID, &dset->shared->layout, 0);
+    if (get_value == 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, 0, "can't get size of layout message")
+    ret_value += get_value;
+
+    /* Fill Value message size */
+    get_value = H5O_msg_size_oh(file, ohdr, H5O_FILL_NEW_ID, fill_prop, 0);
+    if (get_value == 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, 0, "can't get size of fill value message")
+    ret_value += get_value;
+
+    /* "Continuation" message size */
+    /* message pointer "continuation" is unused by raw get function, however,
+     * a null pointer would be intercepted by an assert in H5O_msg_size_oh().
+     */
+    get_value = H5O_msg_size_oh(file, ohdr, H5O_CONT_ID, continuation, 0);
+    if (get_value == 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, 0, "can't get size of continuation message")
+    ret_value += get_value;
+
+    /* Fill Value (backwards compatability) message size */
+    if(fill_prop->buf && !use_at_least_v18) {
+        H5O_fill_t old_fill_prop; /* Copy for writing "old" fill value */
+
+        /* Shallow copy the fill value property */
+        /* guards against shared component modification */
+        HDmemcpy(&old_fill_prop, fill_prop, sizeof(old_fill_prop));
+
+        if (H5O_msg_reset_share(H5O_FILL_ID, &old_fill_prop) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, 0, "can't reset the copied fill property")
+
+        get_value = H5O_msg_size_oh(file, ohdr, H5O_FILL_ID, &old_fill_prop, 0);
+        if (get_value == 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, 0, "can't get size of fill value (backwards compat) message")
+        ret_value += get_value;
+    }
+
+    /* Filter/Pipeline message size */
+    if(H5D_CHUNKED == dset->shared->layout.type) {
+        H5O_pline_t *pline = &dset->shared->dcpl_cache.pline;
+        if(pline->nused > 0) {
+            get_value = H5O_msg_size_oh(file, ohdr, H5O_PLINE_ID, pline, 0);
+            if (get_value == 0)
+                HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, 0, "can't get size of filter message")
+            ret_value += get_value;
+        }
+    }
+
+    /* External File Link message size */
+    if(dset->shared->dcpl_cache.efl.nused > 0) {
+        get_value = H5O_msg_size_oh(file, ohdr, H5O_EFL_ID, &dset->shared->dcpl_cache.efl, 0);
+        if (get_value == 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, 0, "can't get size of external file link message")
+        ret_value += get_value;
+    }
+
+    /* Modification Time message size */
+    if(H5O_HDR_STORE_TIMES & H5O_OH_GET_FLAGS(ohdr)) {
+        HDassert(H5O_OH_GET_VERSION(ohdr) >= 1); /* 1 :: H5O_VERSION_1 (H5Opkg.h) */
+
+        if(H5O_OH_GET_VERSION(ohdr) == 1) {
+            /* v1 object headers store modification time as a message */
+            time_t mtime;
+            get_value = H5O_msg_size_oh(file, ohdr, H5O_MTIME_NEW_ID, &mtime, 0);
+            if (get_value == 0)
+                HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, 0, "can't get size of modification time message")
+            ret_value += get_value;
+        }
+    }
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+} /* H5D__calculate_minimum_header_size */
+
+
+/*-------------------------------------------------------------------------
+ * Function:   H5D__prepare_minimized_oh
+ *
+ * Purpose:    Create an object header (H5O_t) allocated with the smallest
+ *             possible size.
+ *
+ * Return:     Success: SUCCEED (0) (non-negative value)
+ *             Failure: FAIL (-1) (negative value)
+ *
+ * Programmer: Jacob Smith
+ *             16 August 2018
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D__prepare_minimized_oh(H5F_t *file, H5D_t *dset, H5O_loc_t *oloc)
+{
+    H5O_t  *oh        = NULL;
+    size_t  ohdr_size = 0;
+    herr_t  ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI_NOINIT;
+
+    HDassert(file);
+    HDassert(dset);
+    HDassert(oloc);
+
+    oh = H5O__create_ohdr(file, dset->shared->dcpl_id);
+    if(NULL == oh)
+        HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, FAIL, "can't instantiate object header")
+
+    ohdr_size = H5D__calculate_minimum_header_size(file, dset, oh);
+    if (ohdr_size == 0)
+       HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, FAIL, "computed header size is invalid")
+
+    /* Special allocation of space for compact datsets is handled by the call here. */
+    if(H5O__apply_ohdr(file, oh, dset->shared->dcpl_id, ohdr_size, (size_t)1, oloc) == FAIL)
+        HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, FAIL, "can't apply object header to file")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+} /* H5D__prepare_minimized_oh */
+
+
+/*-------------------------------------------------------------------------
  * Function: H5D__update_oh_info
  *
  * Purpose:  Create and fill object header for dataset
@@ -669,17 +878,18 @@ done:
 static herr_t
 H5D__update_oh_info(H5F_t *file, H5D_t *dset, hid_t dapl_id)
 {
-    H5O_t              *oh = NULL;      /* Pointer to dataset's object header */
-    size_t              ohdr_size = H5D_MINHDR_SIZE;    /* Size of dataset's object header */
-    H5O_loc_t          *oloc = NULL;    /* Dataset's object location */
-    H5O_layout_t       *layout;         /* Dataset's layout information */
-    H5T_t              *type;           /* Dataset's datatype */
-    H5O_fill_t         *fill_prop;      /* Pointer to dataset's fill value information */
-    H5D_fill_value_t    fill_status;    /* Fill value status */
-    hbool_t             fill_changed = FALSE;   /* Flag indicating the fill value was changed */
-    hbool_t             layout_init = FALSE;    /* Flag to indicate that chunk information was initialized */
-    hbool_t             use_at_least_v18;       /* Flag indicating to use at least v18 format versions */
-    herr_t ret_value = SUCCEED;         /* Return value */
+    H5O_t            *oh = NULL;      /* Pointer to dataset's object header */
+    size_t            ohdr_size = H5D_MINHDR_SIZE;    /* Size of dataset's object header */
+    H5O_loc_t        *oloc = NULL;    /* Dataset's object location */
+    H5O_layout_t     *layout;         /* Dataset's layout information */
+    H5T_t            *type;           /* Dataset's datatype */
+    H5O_fill_t       *fill_prop;      /* Pointer to dataset's fill value information */
+    H5D_fill_value_t  fill_status;    /* Fill value status */
+    hbool_t           fill_changed = FALSE;   /* Flag indicating the fill value was changed */
+    hbool_t           layout_init = FALSE;    /* Flag to indicate that chunk information was initialized */
+    hbool_t           use_at_least_v18;       /* Flag indicating to use at least v18 format versions */
+    hbool_t           minimize_header = FALSE;
+    herr_t            ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_STATIC
 
@@ -747,13 +957,24 @@ H5D__update_oh_info(H5F_t *file, H5D_t *dset, hid_t dapl_id)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set fill value info")
     } /* end if */
 
-    /* Add the dataset's raw data size to the size of the header, if the raw data will be stored as compact */
-    if(layout->type == H5D_COMPACT)
-        ohdr_size += layout->storage.u.compact.size;
+    if(H5D__use_minimized_dset_headers(file, dset, &minimize_header) == FAIL)
+        HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get minimize settings")
+
+    if(TRUE == minimize_header) {
+        if(H5D__prepare_minimized_oh(file, dset, oloc) == FAIL)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "can't create minimized dataset object header")
+    } else {
+        /* Add the dataset's raw data size to the size of the header, if the
+         * raw data will be stored as compact
+         */
+        if(H5D_COMPACT == layout->type)
+            ohdr_size += layout->storage.u.compact.size;
+
+        /* Create an object header for the dataset */
+        if(H5O_create(file, ohdr_size, (size_t)1, dset->shared->dcpl_id, oloc/*out*/) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to create dataset object header")
+    } /* If use minimum/standard object header space */
 
-    /* Create an object header for the dataset */
-    if(H5O_create(file, ohdr_size, (size_t)1, dset->shared->dcpl_id, oloc/*out*/) < 0)
-        HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to create dataset object header")
     HDassert(file == dset->oloc.file);
 
     /* Pin the object header */
@@ -910,7 +1131,7 @@ H5D__build_file_prefix(const H5D_t *dset, hid_t dapl_id, const char *prefix_type
             HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed")
     } /* end if */
     else {
-        if (HDstrncmp(prefix, "${ORIGIN}", HDstrlen("${ORIGIN}")) == 0) {
+        if(HDstrncmp(prefix, "${ORIGIN}", HDstrlen("${ORIGIN}")) == 0) {
             /* Replace ${ORIGIN} at beginning of prefix by directory of HDF5 file */
             filepath_len = HDstrlen(filepath);
             prefix_len = HDstrlen(prefix);
diff --git a/src/H5Dio.c b/src/H5Dio.c
index 037d443..fe85d23 100644
--- a/src/H5Dio.c
+++ b/src/H5Dio.c
@@ -30,6 +30,8 @@
 #include "H5MMprivate.h"        /* Memory management                        */
 #include "H5Sprivate.h"         /* Dataspace                                */
 
+#include "H5VLnative_private.h" /* Native VOL connector                     */
+
 #ifdef H5_HAVE_PARALLEL
 /* Remove this if H5R_DATASET_REGION is no longer used in this file */
 #include "H5Rpublic.h"
diff --git a/src/H5Dprivate.h b/src/H5Dprivate.h
index 4e9cda8..aaa3db2 100644
--- a/src/H5Dprivate.h
+++ b/src/H5Dprivate.h
@@ -45,6 +45,7 @@
 #define H5D_CRT_FILL_VALUE_NAME    "fill_value"          /* Fill value */
 #define H5D_CRT_ALLOC_TIME_STATE_NAME "alloc_time_state" /* Space allocation time state */
 #define H5D_CRT_EXT_FILE_LIST_NAME "efl"                 /* External file list */
+#define H5D_CRT_MIN_DSET_HDR_SIZE_NAME "dset_oh_minimize"/* Minimize object header */
 
 /* ========  Dataset access property names ======== */
 #define H5D_ACS_DATA_CACHE_NUM_SLOTS_NAME   "rdcc_nslots"    /* Size of raw data chunk cache(slots) */
diff --git a/src/H5Dpublic.h b/src/H5Dpublic.h
index 921974d..63f1a24 100644
--- a/src/H5Dpublic.h
+++ b/src/H5Dpublic.h
@@ -104,27 +104,6 @@ typedef enum H5D_vds_view_t {
 /* Callback for H5Pset_append_flush() in a dataset access property list */
 typedef herr_t (*H5D_append_cb_t)(hid_t dataset_id, hsize_t *cur_dims, void *op_data);
 
-/* Enumeration for native VOL connector dataset optional VOL operations */
-typedef enum H5VL_native_dataset_optional_t {
-    H5VL_NATIVE_DATASET_FORMAT_CONVERT,             /* H5Dformat_convert (internal) */
-    H5VL_NATIVE_DATASET_GET_CHUNK_INDEX_TYPE,       /* H5Dget_chunk_index_type      */
-    H5VL_NATIVE_DATASET_GET_CHUNK_STORAGE_SIZE,     /* H5Dget_chunk_storage_size    */
-    H5VL_NATIVE_DATASET_CHUNK_READ,                 /* H5Dchunk_read                */
-    H5VL_NATIVE_DATASET_CHUNK_WRITE,                /* H5Dchunk_write               */
-} H5VL_native_dataset_optional_t;
-
-
-/********************/
-/* Public Variables */
-/********************/
-
-/*********************/
-/* Public Prototypes */
-/*********************/
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 /* Define the operator function pointer for H5Diterate() */
 typedef herr_t (*H5D_operator_t)(void *elem, hid_t type_id, unsigned ndim,
 				 const hsize_t *point, void *operator_data);
@@ -138,6 +117,18 @@ typedef herr_t (*H5D_scatter_func_t)(const void **src_buf/*out*/,
 typedef herr_t (*H5D_gather_func_t)(const void *dst_buf,
                                     size_t dst_buf_bytes_used, void *op_data);
 
+
+/********************/
+/* Public Variables */
+/********************/
+
+/*********************/
+/* Public Prototypes */
+/*********************/
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 H5_DLL hid_t H5Dcreate2(hid_t loc_id, const char *name, hid_t type_id,
     hid_t space_id, hid_t lcpl_id, hid_t dcpl_id, hid_t dapl_id);
 H5_DLL hid_t H5Dcreate_anon(hid_t file_id, hid_t type_id, hid_t space_id,
diff --git a/src/H5F.c b/src/H5F.c
index 3937609..0ff3f1f 100644
--- a/src/H5F.c
+++ b/src/H5F.c
@@ -38,6 +38,8 @@
 #include "H5Tprivate.h"         /* Datatypes                                */
 #include "H5VLprivate.h"        /* Virtual Object Layer                     */
 
+#include "H5VLnative_private.h" /* Native VOL connector                     */
+
 
 /****************/
 /* Local Macros */
@@ -778,7 +780,7 @@ H5Fflush(hid_t object_id, H5F_scope_t scope)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
 
     /* Flush the object */
-    if(H5VL_file_specific(vol_obj, H5VL_FILE_FLUSH, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, obj_type, scope) < 0)
+    if(H5VL_file_specific(vol_obj, H5VL_FILE_FLUSH, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, (int)obj_type, (int)scope) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush file")
 
 done:
@@ -1260,7 +1262,7 @@ H5Fget_name(hid_t obj_id, char *name/*out*/, size_t size)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, (-1), "invalid file identifier")
 
     /* Get the filename via the VOL */
-    if(H5VL_file_get(vol_obj, H5VL_FILE_GET_NAME, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, type, size, name, &ret_value) < 0)
+    if(H5VL_file_get(vol_obj, H5VL_FILE_GET_NAME, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, (int)type, size, name, &ret_value) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTGET, (-1), "unable to get file name")
 
 done:
@@ -1305,7 +1307,7 @@ H5Fget_info2(hid_t obj_id, H5F_info2_t *finfo)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
 
     /* Get the file information */
-    if(H5VL_file_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_FILE_GET_INFO, type, finfo) < 0)
+    if(H5VL_file_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_FILE_GET_INFO, (int)type, finfo) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to retrieve file info")
 
 done:
@@ -1333,7 +1335,7 @@ H5Fget_metadata_read_retry_info(hid_t file_id, H5F_retry_info_t *info)
     H5TRACE2("e", "i*x", file_id, info);
 
     /* Check args */
-    if (!info)
+    if(!info)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no info struct")
 
     /* Get the file pointer */
@@ -1380,7 +1382,7 @@ H5Fget_free_sections(hid_t file_id, H5F_mem_t type, size_t nsects,
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, (-1), "nsects must be > 0")
 
     /* Get the free-space section information in the file */
-    if(H5VL_file_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_FILE_GET_FREE_SECTIONS, sect_info, &ret_value, type, nsects) < 0)
+    if(H5VL_file_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_FILE_GET_FREE_SECTIONS, sect_info, &ret_value, (int)type, nsects) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTGET, (-1), "unable to get file free sections")
 
 done:
@@ -1506,7 +1508,7 @@ H5Fstart_mdc_logging(hid_t file_id)
 
     /* Call mdc logging function */
     if(H5VL_file_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_FILE_START_MDC_LOGGING) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_LOGFAIL, FAIL, "unable to start mdc logging")
+        HGOTO_ERROR(H5E_FILE, H5E_LOGGING, FAIL, "unable to start mdc logging")
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -1539,7 +1541,7 @@ H5Fstop_mdc_logging(hid_t file_id)
 
     /* Call mdc logging function */
     if(H5VL_file_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_FILE_STOP_MDC_LOGGING) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_LOGFAIL, FAIL, "unable to stop mdc logging")
+        HGOTO_ERROR(H5E_FILE, H5E_LOGGING, FAIL, "unable to stop mdc logging")
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -1573,7 +1575,7 @@ H5Fget_mdc_logging_status(hid_t file_id, hbool_t *is_enabled,
 
     /* Call mdc logging function */
     if(H5VL_file_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_FILE_GET_MDC_LOGGING_STATUS, is_enabled, is_currently_logging) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_LOGFAIL, FAIL, "unable to get logging status")
+        HGOTO_ERROR(H5E_FILE, H5E_LOGGING, FAIL, "unable to get logging status")
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -1820,3 +1822,89 @@ done:
     FUNC_LEAVE_API(ret_value)
 } /* H5Fincrement_filesize() */
 
+
+/*-------------------------------------------------------------------------
+ * Function: H5Fget_dset_no_attrs_hint
+ *
+ * Purpose:
+ *
+ *     Get the file-level setting to create minimized dataset object headers.
+ *     Result is stored at pointer `minimize`.
+ *
+ * Return:
+ *
+ *     Success: SUCCEED (0) (non-negative value)
+ *     Failure: FAIL (-1) (negative value)
+ *
+ * Programmer:
+ *
+ *     Jacob Smith
+ *     15 August 2018
+ *
+ * Changes: None.
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Fget_dset_no_attrs_hint(hid_t file_id, hbool_t *minimize)
+{
+    H5VL_object_t  *vol_obj   = NULL;
+    herr_t          ret_value = SUCCEED;
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE2("e", "i*b", file_id, minimize);
+
+    if(NULL == minimize)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "out pointer 'minimize' cannot be NULL")
+
+    vol_obj = (H5VL_object_t *)H5I_object_verify(file_id, H5I_FILE);
+    if(NULL == vol_obj)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
+
+    if(H5VL_file_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_FILE_GET_MIN_DSET_OHDR_FLAG, minimize) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "unable to set file's dataset header minimization flag")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* H5Fget_dset_no_attrs_hint */
+
+
+/*-------------------------------------------------------------------------
+ * Function: H5Fset_dset_no_attrs_hint
+ *
+ * Purpose:
+ *
+ *     Set the file-level setting to create minimized dataset object headers.
+ *
+ * Return:
+ *
+ *     Success: SUCCEED (0) (non-negative value)
+ *     Failure: FAIL (-1) (negative value)
+ *
+ * Programmer:
+ *
+ *     Jacob Smith
+ *     15 August 2018
+ *
+ * Changes: None.
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Fset_dset_no_attrs_hint(hid_t file_id, hbool_t minimize)
+{
+    H5VL_object_t *vol_obj   = NULL;
+    herr_t         ret_value = SUCCEED;
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE2("e", "ib", file_id, minimize);
+
+    vol_obj = (H5VL_object_t *)H5I_object_verify(file_id, H5I_FILE);
+    if(NULL == vol_obj)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
+
+    if(H5VL_file_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_FILE_SET_MIN_DSET_OHDR_FLAG, minimize) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "unable to set file's dataset header minimization flag")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* H5Fset_dset_no_attrs_hint */
+
diff --git a/src/H5FDcore.c b/src/H5FDcore.c
index 391e37e..ed05e95 100644
--- a/src/H5FDcore.c
+++ b/src/H5FDcore.c
@@ -54,6 +54,7 @@ typedef struct H5FD_core_t {
     haddr_t eof;                /* current allocated size               */
     size_t  increment;          /* multiples for mem allocation         */
     hbool_t backing_store;      /* write to file name on flush          */
+    hbool_t write_tracking;     /* Whether to track writes              */
     size_t  bstore_page_size;   /* backing store page size              */
     int     fd;                 /* backing store file descriptor        */
     /* Information for determining uniqueness of a file with a backing store */
@@ -93,10 +94,14 @@ typedef struct H5FD_core_t {
 typedef struct H5FD_core_fapl_t {
     size_t  increment;          /* how much to grow memory */
     hbool_t backing_store;      /* write to file name on flush */
+    hbool_t write_tracking;     /* Whether to track writes */
+    size_t page_size;           /* Page size for tracked writes */
 } H5FD_core_fapl_t;
 
 /* Allocate memory in multiples of this size by default */
-#define H5FD_CORE_INCREMENT 8192
+#define H5FD_CORE_INCREMENT                     8192
+#define H5FD_CORE_WRITE_TRACKING_FLAG           FALSE
+#define H5FD_CORE_WRITE_TRACKING_PAGE_SIZE      524288
 
 /* These macros check for overflow of various quantities.  These macros
  * assume that file_offset_t is signed and haddr_t and size_t are unsigned.
@@ -466,6 +471,100 @@ H5FD__core_term(void)
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5Pset_core_write_tracking
+ *
+ * Purpose:    Enables/disables core VFD write tracking and page
+ *              aggregation size.
+ *
+ * Return:    Non-negative on success/Negative on failure
+ *
+ * Programmer:  Dana Robinson
+ *              Tuesday, April 8, 2014
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pset_core_write_tracking(hid_t plist_id, hbool_t is_enabled, size_t page_size)
+{
+    H5P_genplist_t *plist;              /* Property list pointer */
+    H5FD_core_fapl_t fa;                /* Core VFD info */
+    const H5FD_core_fapl_t *old_fa;     /* Old core VFD info */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE3("e", "ibz", plist_id, is_enabled, page_size);
+
+    /* The page size cannot be zero */
+    if(page_size == 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "page_size cannot be zero")
+
+    /* Get the plist structure */
+    if(NULL == (plist = H5P_object_verify(plist_id, H5P_FILE_ACCESS)))
+        HGOTO_ERROR(H5E_PLIST, H5E_BADATOM, FAIL, "can't find object for ID")
+    if(H5FD_CORE != H5P_peek_driver(plist))
+        HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, FAIL, "incorrect VFL driver")
+    if(NULL == (old_fa = (const H5FD_core_fapl_t *)H5P_peek_driver_info(plist)))
+        HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, FAIL, "bad VFL driver info")
+
+    /* Set VFD info values */
+    HDmemset(&fa, 0, sizeof(H5FD_core_fapl_t));
+    fa.increment = old_fa->increment;
+    fa.backing_store = old_fa->backing_store;
+    fa.write_tracking = is_enabled;
+    fa.page_size = page_size;
+
+    /* Set the property values & the driver for the FAPL */
+    if(H5P_set_driver(plist, H5FD_CORE, &fa) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set core VFD as driver")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5Pset_core_write_tracking() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5Pget_core_write_tracking
+ *
+ * Purpose:    Gets information about core VFD write tracking and page
+ *              aggregation size.
+ *
+ * Return:    Non-negative on success/Negative on failure
+ *
+ * Programmer:  Dana Robinson
+ *              Tuesday, April 8, 2014
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pget_core_write_tracking(hid_t plist_id, hbool_t *is_enabled, size_t *page_size)
+{
+    H5P_genplist_t *plist;      /* Property list pointer */
+    const H5FD_core_fapl_t *fa; /* Core VFD info */
+    herr_t ret_value = SUCCEED; /* Return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE3("e", "i*b*z", plist_id, is_enabled, page_size);
+
+    /* Get the plist structure */
+    if(NULL == (plist = H5P_object_verify(plist_id, H5P_FILE_ACCESS)))
+        HGOTO_ERROR(H5E_PLIST, H5E_BADATOM, FAIL, "can't find object for ID")
+    if(H5FD_CORE != H5P_peek_driver(plist))
+        HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, FAIL, "incorrect VFL driver")
+    if(NULL == (fa = (const H5FD_core_fapl_t *)H5P_peek_driver_info(plist)))
+        HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, FAIL, "bad VFL driver info")
+
+    /* Get values */
+    if(is_enabled)
+        *is_enabled = fa->write_tracking;
+    if(page_size)
+        *page_size = fa->page_size;
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5Pget_core_write_tracking() */
+
+
+/*-------------------------------------------------------------------------
  * Function:    H5Pset_fapl_core
  *
  * Purpose:     Modify the file access property list to use the H5FD_CORE
@@ -482,9 +581,9 @@ H5FD__core_term(void)
 herr_t
 H5Pset_fapl_core(hid_t fapl_id, size_t increment, hbool_t backing_store)
 {
-    H5FD_core_fapl_t    fa;
-    H5P_genplist_t      *plist;         /* Property list pointer */
-    herr_t              ret_value;
+    H5P_genplist_t *plist;      /* Property list pointer */
+    H5FD_core_fapl_t fa;        /* Core VFD info */
+    herr_t ret_value = SUCCEED; /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE3("e", "izb", fapl_id, increment, backing_store);
@@ -493,10 +592,16 @@ H5Pset_fapl_core(hid_t fapl_id, size_t increment, hbool_t backing_store)
     if(NULL == (plist = H5P_object_verify(fapl_id,H5P_FILE_ACCESS)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file access property list")
 
+    /* Set VFD info values */
+    HDmemset(&fa, 0, sizeof(H5FD_core_fapl_t));
     fa.increment = increment;
     fa.backing_store = backing_store;
+    fa.write_tracking = H5FD_CORE_WRITE_TRACKING_FLAG;
+    fa.page_size = H5FD_CORE_WRITE_TRACKING_PAGE_SIZE;
 
-    ret_value = H5P_set_driver(plist, H5FD_CORE, &fa);
+    /* Set the property values & the driver for the FAPL */
+    if(H5P_set_driver(plist, H5FD_CORE, &fa) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set core VFD as driver")
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -518,9 +623,9 @@ done:
 herr_t
 H5Pget_fapl_core(hid_t fapl_id, size_t *increment /*out*/, hbool_t *backing_store /*out*/)
 {
-    H5P_genplist_t      *plist;                 /* Property list pointer */
-    const H5FD_core_fapl_t    *fa;
-    herr_t              ret_value = SUCCEED;    /* Return value */
+    H5P_genplist_t *plist;      /* Property list pointer */
+    const H5FD_core_fapl_t *fa; /* Core VFD info */
+    herr_t ret_value = SUCCEED; /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE3("e", "ixx", fapl_id, increment, backing_store);
@@ -559,7 +664,7 @@ static void *
 H5FD__core_fapl_get(H5FD_t *_file)
 {
     H5FD_core_t         *file = (H5FD_core_t*)_file;
-    H5FD_core_fapl_t    *fa;
+    H5FD_core_fapl_t    *fa;                    /* Core VFD info */
     void                *ret_value = NULL;      /* Return value */
 
     FUNC_ENTER_STATIC
@@ -569,6 +674,8 @@ H5FD__core_fapl_get(H5FD_t *_file)
 
     fa->increment = file->increment;
     fa->backing_store = (hbool_t)(file->fd >= 0);
+    fa->write_tracking = file->write_tracking;
+    fa->page_size = file->bstore_page_size;
 
     /* Set return value */
     ret_value = fa;
@@ -776,35 +883,28 @@ H5FD__core_open(const char *name, unsigned flags, hid_t fapl_id, haddr_t maxaddr
         } /* end if */
     } /* end if */
 
+    /* Get the write tracking & page size */
+    file->write_tracking = fa->write_tracking;
+    file->bstore_page_size = fa->page_size;
+
     /* Set up write tracking if the backing store is on */
     file->dirty_list = NULL;
     if(fa->backing_store) {
-        hbool_t write_tracking_flag = FALSE;    /* what the user asked for */
         hbool_t use_write_tracking = FALSE;     /* what we're actually doing */
 
-        /* Get the write tracking flag */
-        if(H5P_get(plist, H5F_ACS_CORE_WRITE_TRACKING_FLAG_NAME, &write_tracking_flag) < 0)
-            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get core VFD write tracking flag");
-
-        /* Get the page size */
-        if(H5P_get(plist, H5F_ACS_CORE_WRITE_TRACKING_PAGE_SIZE_NAME, &(file->bstore_page_size)) < 0)
-            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get core VFD write tracking page size");
-
         /* default is to have write tracking OFF for create (hence the check to see
          * if the user explicitly set a page size) and ON with the default page size
          * on open (when not read-only).
          */
         /* Only use write tracking if the file is open for writing */
-        use_write_tracking = 
-            TRUE == write_tracking_flag         /* user asked for write tracking */
-            && !(o_flags & O_RDONLY)            /* file is open for writing (i.e. not read-only) */
-            && file->bstore_page_size != 0;     /* page size is not zero */
+        use_write_tracking = (TRUE == fa->write_tracking)    /* user asked for write tracking */
+                    && !(o_flags & O_RDONLY)                /* file is open for writing (i.e. not read-only) */
+                    && (file->bstore_page_size != 0);         /* page size is not zero */
 
         /* initialize the dirty list */
-        if(use_write_tracking) {
+        if(use_write_tracking)
             if(NULL == (file->dirty_list = H5SL_create(H5SL_TYPE_HADDR, NULL)))
                 HGOTO_ERROR(H5E_SLIST, H5E_CANTCREATE, NULL, "can't create core vfd dirty region list");
-        } /* end if */
     } /* end if */
 
     /* Set return value */
diff --git a/src/H5FDdirect.c b/src/H5FDdirect.c
index 4476654..10c368a 100644
--- a/src/H5FDdirect.c
+++ b/src/H5FDdirect.c
@@ -288,6 +288,7 @@ H5Pset_fapl_direct(hid_t fapl_id, size_t boundary, size_t block_size, size_t cbu
     if(NULL == (plist = H5P_object_verify(fapl_id,H5P_FILE_ACCESS)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file access property list")
 
+    HDmemset(&fa, 0, sizeof(H5FD_direct_fapl_t));
     if(boundary != 0)
         fa.mboundary = boundary;
     else
@@ -414,7 +415,7 @@ static void *
 H5FD_direct_fapl_copy(const void *_old_fa)
 {
     const H5FD_direct_fapl_t *old_fa = (const H5FD_direct_fapl_t*)_old_fa;
-    H5FD_direct_fapl_t *new_fa = H5MM_malloc(sizeof(H5FD_direct_fapl_t));
+    H5FD_direct_fapl_t *new_fa = H5MM_calloc(sizeof(H5FD_direct_fapl_t));
 
     FUNC_ENTER_NOAPI_NOINIT_NOERR
 
diff --git a/src/H5FDlog.c b/src/H5FDlog.c
index 524113a..97d1b41 100644
--- a/src/H5FDlog.c
+++ b/src/H5FDlog.c
@@ -329,6 +329,8 @@ H5Pset_fapl_log(hid_t fapl_id, const char *logfile, unsigned long long flags, si
     if(NULL == (plist = H5P_object_verify(fapl_id, H5P_FILE_ACCESS)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file access property list")
 
+    HDmemset(&fa, 0, sizeof(H5FD_log_fapl_t));
+
     /* This shallow copy is correct! The string will be properly 
      * copied deep down in the H5P code. 
      */
diff --git a/src/H5FDmpio.c b/src/H5FDmpio.c
index f9d1032..a5180d0 100644
--- a/src/H5FDmpio.c
+++ b/src/H5FDmpio.c
@@ -321,6 +321,7 @@ H5Pset_fapl_mpio(hid_t fapl_id, MPI_Comm comm, MPI_Info info)
 	HGOTO_ERROR(H5E_PLIST, H5E_BADTYPE, FAIL, "not a valid communicator")
 
     /* Initialize driver specific properties */
+    HDmemset(&fa, 0, sizeof(H5FD_mpio_fapl_t));
     fa.comm = comm;
     fa.info = info;
 
diff --git a/src/H5FDmulti.c b/src/H5FDmulti.c
index ff41371..fac0909 100644
--- a/src/H5FDmulti.c
+++ b/src/H5FDmulti.c
@@ -491,6 +491,7 @@ H5Pset_fapl_multi(hid_t fapl_id, const H5FD_mem_t *memb_map,
      * Initialize driver specific information. No need to copy it into the FA
      * struct since all members will be copied by H5Pset_driver().
      */
+    memset(&fa, 0, sizeof(H5FD_multi_fapl_t));
     memcpy(fa.memb_map, memb_map, H5FD_MEM_NTYPES*sizeof(H5FD_mem_t));
     memcpy(fa.memb_fapl, memb_fapl, H5FD_MEM_NTYPES*sizeof(hid_t));
     memcpy(fa.memb_name, memb_name, H5FD_MEM_NTYPES*sizeof(char*));
@@ -886,7 +887,7 @@ static void *
 H5FD_multi_fapl_copy(const void *_old_fa)
 {
     const H5FD_multi_fapl_t *old_fa = (const H5FD_multi_fapl_t*)_old_fa;
-    H5FD_multi_fapl_t *new_fa = (H5FD_multi_fapl_t *)malloc(sizeof(H5FD_multi_fapl_t));
+    H5FD_multi_fapl_t *new_fa = (H5FD_multi_fapl_t *)calloc(1, sizeof(H5FD_multi_fapl_t));
     int nerrors = 0;
     static const char *func="H5FD_multi_fapl_copy";  /* Function Name for error reporting */
 
diff --git a/src/H5Fdeprec.c b/src/H5Fdeprec.c
index 1a2418d..18e915f 100644
--- a/src/H5Fdeprec.c
+++ b/src/H5Fdeprec.c
@@ -42,6 +42,8 @@
 #include "H5Iprivate.h"         /* IDs                                      */
 #include "H5SMprivate.h"        /* Shared object header messages            */
 
+#include "H5VLnative_private.h" /* Native VOL connector                     */
+
 
 /****************/
 /* Local Macros */
@@ -225,7 +227,7 @@ H5Fset_latest_format(hid_t file_id, hbool_t latest_format)
         low = H5F_LIBVER_EARLIEST;
 
     /* Set the library's version bounds */
-    if(H5VL_file_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_FILE_SET_LIBVER_BOUNDS, low, high) < 0)
+    if(H5VL_file_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_FILE_SET_LIBVER_BOUNDS, (int)low, (int)high) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "can't set library version bounds")
 
 done:
diff --git a/src/H5Fint.c b/src/H5Fint.c
index b212657..cca46d0 100644
--- a/src/H5Fint.c
+++ b/src/H5Fint.c
@@ -39,6 +39,8 @@
 #include "H5Tprivate.h"         /* Datatypes                                */
 #include "H5VLprivate.h"        /* Virtual Object Layer                     */
 
+#include "H5VLnative_private.h" /* Native VOL connector                     */
+
 
 /****************/
 /* Local Macros */
@@ -3701,7 +3703,7 @@ H5F_get_file_id(hid_t obj_id, H5I_type_t type)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid identifier")
 
     /* Get the file through the VOL */
-    if(H5VL_file_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_FILE_GET_FILE_ID, type, &file_id) < 0)
+    if(H5VL_file_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_FILE_GET_FILE_ID, (int)type, &file_id) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, H5I_INVALID_HID, "unable to get file ID")
     if(H5I_INVALID_HID == file_id)
         HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, H5I_INVALID_HID, "unable to get the file ID through the VOL")
@@ -3713,3 +3715,27 @@ done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5F_get_file_id() */
 
+
+/*-------------------------------------------------------------------------
+ * Function:    H5F_set_min_dset_ohdr
+ *
+ * Purpose:     Set the crt_dset_ohdr_flag field with a new value.
+ *
+ * Return:      SUCCEED/FAIL
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_set_min_dset_ohdr(H5F_t *f, hbool_t minimize)
+{
+    /* Use FUNC_ENTER_NOAPI_NOINIT_NOERR here to avoid performance issues */
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    /* Sanity check */
+    HDassert(f);
+    HDassert(f->shared);
+
+    f->shared->crt_dset_min_ohdr_flag = minimize;
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* H5F_set_min_dset_ohdr() */
+
diff --git a/src/H5Fmount.c b/src/H5Fmount.c
index d7f8915..13d95aa 100644
--- a/src/H5Fmount.c
+++ b/src/H5Fmount.c
@@ -482,7 +482,7 @@ H5Fmount(hid_t loc_id, const char *name, hid_t child_id, hid_t plist_id)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "Can't mount file onto object from different VOL connector")
 
     /* Perform the mount operation */
-    if(H5VL_file_specific(loc_vol_obj, H5VL_FILE_MOUNT, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, loc_type, name, child_vol_obj->data, plist_id) < 0)
+    if(H5VL_file_specific(loc_vol_obj, H5VL_FILE_MOUNT, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, (int)loc_type, name, child_vol_obj->data, plist_id) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "unable to mount file")
 
 done:
@@ -534,7 +534,7 @@ H5Funmount(hid_t loc_id, const char *name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "could not get location object")
 
     /* Perform the unmount operation */
-    if(H5VL_file_specific(vol_obj, H5VL_FILE_UNMOUNT, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, loc_type, name) < 0)
+    if(H5VL_file_specific(vol_obj, H5VL_FILE_UNMOUNT, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, (int)loc_type, name) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "unable to unmount file")
 
 done:
diff --git a/src/H5Fpkg.h b/src/H5Fpkg.h
index 4ad2c55..335d0a7 100644
--- a/src/H5Fpkg.h
+++ b/src/H5Fpkg.h
@@ -358,6 +358,7 @@ struct H5F_file_t {
 
     /* Object flush info */
     H5F_object_flush_t 	object_flush;	    /* Information for object flush callback */
+    hbool_t crt_dset_min_ohdr_flag; /* flag to minimize created dataset object header */
 };
 
 /*
@@ -382,7 +383,6 @@ struct H5F_t {
 #endif /* H5_HAVE_PARALLEL */
 };
 
-
 /*****************************/
 /* Package Private Variables */
 /*****************************/
diff --git a/src/H5Fprivate.h b/src/H5Fprivate.h
index 83513a5..5f7a1b2 100644
--- a/src/H5Fprivate.h
+++ b/src/H5Fprivate.h
@@ -331,6 +331,8 @@ typedef struct H5F_t H5F_t;
 #define H5F_POINT_OF_NO_RETURN(F) ((F)->shared->fs.point_of_no_return)
 #define H5F_FIRST_ALLOC_DEALLOC(F) ((F)->shared->first_alloc_dealloc)
 #define H5F_EOA_PRE_FSM_FSALLOC(F) ((F)->shared->eoa_pre_fsm_fsalloc)
+#define H5F_GET_MIN_DSET_OHDR(F) ((F)->shared->crt_dset_min_ohdr_flag)
+#define H5F_SET_MIN_DSET_OHDR(F, V) ((F)->shared->crt_dset_min_ohdr_flag = (V))
 #else /* H5F_MODULE */
 #define H5F_LOW_BOUND(F)        (H5F_get_low_bound(F))
 #define H5F_HIGH_BOUND(F)       (H5F_get_high_bound(F))
@@ -388,6 +390,8 @@ typedef struct H5F_t H5F_t;
 #define H5F_POINT_OF_NO_RETURN(F) (H5F_get_point_of_no_return(F))
 #define H5F_FIRST_ALLOC_DEALLOC(F) (H5F_get_first_alloc_dealloc(F))
 #define H5F_EOA_PRE_FSM_FSALLOC(F) (H5F_get_eoa_pre_fsm_fsalloc(F))
+#define H5F_GET_MIN_DSET_OHDR(F) (H5F_get_min_dset_ohdr(F))
+#define H5F_SET_MIN_DSET_OHDR(F, V) (H5F_set_min_dset_ohdr((F), (V)))
 #endif /* H5F_MODULE */
 
 
@@ -500,9 +504,7 @@ typedef struct H5F_t H5F_t;
 #define H5F_ACS_USE_MDC_LOGGING_NAME            "use_mdc_logging" /* Whether to use metadata cache logging */
 #define H5F_ACS_MDC_LOG_LOCATION_NAME           "mdc_log_location" /* Name of metadata cache log location */
 #define H5F_ACS_START_MDC_LOG_ON_ACCESS_NAME    "start_mdc_log_on_access" /* Whether logging starts on file create/open */
-#define H5F_ACS_CORE_WRITE_TRACKING_FLAG_NAME   "core_write_tracking_flag" /* Whether or not core VFD backing store write tracking is enabled */
 #define H5F_ACS_EVICT_ON_CLOSE_FLAG_NAME        "evict_on_close_flag" /* Whether or not the metadata cache will evict objects on close */
-#define H5F_ACS_CORE_WRITE_TRACKING_PAGE_SIZE_NAME "core_write_tracking_page_size" /* The page size in kiB when core VFD write tracking is enabled */
 #define H5F_ACS_COLL_MD_WRITE_FLAG_NAME         "collective_metadata_write" /* property indicating whether metadata writes are done collectively or not */
 #define H5F_ACS_META_CACHE_INIT_IMAGE_CONFIG_NAME "mdc_initCacheImageCfg" /* Initial metadata cache image creation configuration */
 #define H5F_ACS_PAGE_BUFFER_SIZE_NAME           "page_buffer_size" /* the maximum size for the page buffer cache */
@@ -742,6 +744,8 @@ H5_DLL hsize_t H5F_get_pgend_meta_thres(const H5F_t *f);
 H5_DLL hbool_t H5F_get_point_of_no_return(const H5F_t *f);
 H5_DLL hbool_t H5F_get_first_alloc_dealloc(const H5F_t *f);
 H5_DLL haddr_t H5F_get_eoa_pre_fsm_fsalloc(const H5F_t *f);
+H5_DLL hbool_t H5F_get_min_dset_ohdr(const H5F_t *f);
+H5_DLL herr_t H5F_set_min_dset_ohdr(H5F_t *f, hbool_t minimize);
 
 /* Functions than retrieve values set/cached from the superblock/FCPL */
 H5_DLL haddr_t H5F_get_base_addr(const H5F_t *f);
diff --git a/src/H5Fpublic.h b/src/H5Fpublic.h
index ec543b6..c4bf0b4 100644
--- a/src/H5Fpublic.h
+++ b/src/H5Fpublic.h
@@ -217,41 +217,13 @@ typedef struct H5F_retry_info_t {
 /* Callback for H5Pset_object_flush_cb() in a file access property list */
 typedef herr_t (*H5F_flush_cb_t)(hid_t object_id, void *udata);
 
-/* Enumeration for native VOL connector file optional VOL operations */
-typedef enum H5VL_native_file_optional_t {
-    H5VL_NATIVE_FILE_CLEAR_ELINK_CACHE,             /* H5Fclear_elink_file_cache            */
-    H5VL_NATIVE_FILE_GET_FILE_IMAGE,                /* H5Fget_file_image                    */
-    H5VL_NATIVE_FILE_GET_FREE_SECTIONS,             /* H5Fget_free_sections                 */
-    H5VL_NATIVE_FILE_GET_FREE_SPACE,                /* H5Fget_freespace                     */
-    H5VL_NATIVE_FILE_GET_INFO,                      /* H5Fget_info1/2                       */
-    H5VL_NATIVE_FILE_GET_MDC_CONF,                  /* H5Fget_mdc_config                    */
-    H5VL_NATIVE_FILE_GET_MDC_HR,                    /* H5Fget_mdc_hit_rate                  */
-    H5VL_NATIVE_FILE_GET_MDC_SIZE,                  /* H5Fget_mdc_size                      */
-    H5VL_NATIVE_FILE_GET_SIZE,                      /* H5Fget_filesize                      */
-    H5VL_NATIVE_FILE_GET_VFD_HANDLE,                /* H5Fget_vfd_handle                    */
-    H5VL_NATIVE_FILE_GET_FILE_ID,                   /* H5Fget_file_id                       */
-    H5VL_NATIVE_FILE_RESET_MDC_HIT_RATE,            /* H5Freset_mdc_hit_rate_stats          */
-    H5VL_NATIVE_FILE_SET_MDC_CONFIG,                /* H5Fset_mdc_config                    */
-    H5VL_NATIVE_FILE_GET_METADATA_READ_RETRY_INFO,  /* H5Fget_metadata_read_retry_info      */
-    H5VL_NATIVE_FILE_START_SWMR_WRITE,              /* H5Fstart_swmr_write                  */
-    H5VL_NATIVE_FILE_START_MDC_LOGGING,             /* H5Fstart_mdc_logging                 */
-    H5VL_NATIVE_FILE_STOP_MDC_LOGGING,              /* H5Fstop_mdc_logging                  */
-    H5VL_NATIVE_FILE_GET_MDC_LOGGING_STATUS,        /* H5Fget_mdc_logging_status            */
-    H5VL_NATIVE_FILE_FORMAT_CONVERT,                /* H5Fformat_convert                    */
-    H5VL_NATIVE_FILE_RESET_PAGE_BUFFERING_STATS,    /* H5Freset_page_buffering_stats        */
-    H5VL_NATIVE_FILE_GET_PAGE_BUFFERING_STATS,      /* H5Fget_page_buffering_stats          */
-    H5VL_NATIVE_FILE_GET_MDC_IMAGE_INFO,            /* H5Fget_mdc_image_info                */
-    H5VL_NATIVE_FILE_GET_EOA,                       /* H5Fget_eoa                           */
-    H5VL_NATIVE_FILE_INCR_FILESIZE,                 /* H5Fincrement_filesize                */
-    H5VL_NATIVE_FILE_SET_LIBVER_BOUNDS              /* H5Fset_latest_format/libver_bounds   */
-} H5VL_native_file_optional_t;
-
-
+/*********************/
+/* Public Prototypes */
+/*********************/
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-/* Functions in H5F.c */
 H5_DLL htri_t H5Fis_accessible(const char *container_name, hid_t fapl_id);
 H5_DLL hid_t  H5Fcreate(const char *filename, unsigned flags,
 		  	  hid_t create_plist, hid_t access_plist);
@@ -302,6 +274,8 @@ H5_DLL herr_t H5Freset_page_buffering_stats(hid_t file_id);
 H5_DLL herr_t H5Fget_page_buffering_stats(hid_t file_id, unsigned accesses[2],
     unsigned hits[2], unsigned misses[2], unsigned evictions[2], unsigned bypasses[2]);
 H5_DLL herr_t H5Fget_mdc_image_info(hid_t file_id, haddr_t *image_addr, hsize_t *image_size);
+H5_DLL herr_t H5Fget_dset_no_attrs_hint(hid_t file_id, hbool_t *minimize);
+H5_DLL herr_t H5Fset_dset_no_attrs_hint(hid_t file_id, hbool_t minimize);
 
 #ifdef H5_HAVE_PARALLEL
 H5_DLL herr_t H5Fset_mpi_atomicity(hid_t file_id, hbool_t flag);
diff --git a/src/H5Fquery.c b/src/H5Fquery.c
index 3147e95..103ad3b 100644
--- a/src/H5Fquery.c
+++ b/src/H5Fquery.c
@@ -514,6 +514,25 @@ H5F_sym_leaf_k(const H5F_t *f)
 
 
 /*-------------------------------------------------------------------------
+ * Function: H5F_get_min_dset_ohdr
+ *
+ * Purpose:  Get the setting flag for minimized dataset object headers
+ *
+ * Return:   TRUE/FALSE as set in file
+ *-------------------------------------------------------------------------
+ */
+hbool_t
+H5F_get_min_dset_ohdr(const H5F_t *f)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    HDassert(f);
+
+    FUNC_LEAVE_NOAPI(f->shared->crt_dset_min_ohdr_flag)
+} /* end H5F_get_min_dset_ohdr */
+
+
+/*-------------------------------------------------------------------------
  * Function: H5F_Kvalue
  *
  * Purpose:  Replaced a macro to retrieve a B-tree key value for a certain
diff --git a/src/H5Gdeprec.c b/src/H5Gdeprec.c
index 07cad55..cb03b5e 100644
--- a/src/H5Gdeprec.c
+++ b/src/H5Gdeprec.c
@@ -45,6 +45,8 @@
 #include "H5Pprivate.h"         /* Property lists                       */
 #include "H5VLprivate.h"        /* Virtual Object Layer                 */
 
+#include "H5VLnative_private.h" /* Native VOL connector                     */
+
 
 /****************/
 /* Local Macros */
@@ -770,19 +772,20 @@ H5Gget_comment(hid_t loc_id, const char *name, size_t bufsize, char *buf)
 {
     H5VL_object_t *vol_obj;             /* Object token of loc_id */
     H5VL_loc_params_t loc_params;
+    ssize_t op_ret;                     /* Return value from operation */
     int	ret_value;                      /* Return value */
 
-    FUNC_ENTER_API(FAIL)
+    FUNC_ENTER_API(-1)
     H5TRACE4("Is", "i*sz*s", loc_id, name, bufsize, buf);
 
     if(!name || !*name)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name specified")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, -1, "no name specified")
     if(bufsize > 0 && !buf)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no buffer specified")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, -1, "no buffer specified")
 
     /* Set up collective metadata if appropriate */
     if(H5CX_set_loc(loc_id) < 0)
-        HGOTO_ERROR(H5E_SYM, H5E_CANTSET, FAIL, "can't set collective metadata read info")
+        HGOTO_ERROR(H5E_SYM, H5E_CANTSET, -1, "can't set collective metadata read info")
 
     /* Fill in location struct fields */
     loc_params.type                         = H5VL_OBJECT_BY_NAME;
@@ -792,11 +795,14 @@ H5Gget_comment(hid_t loc_id, const char *name, size_t bufsize, char *buf)
 
     /* Get the location object */
     if(NULL == (vol_obj = H5VL_vol_object(loc_id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, -1, "invalid location identifier")
 
     /* Get the comment */
-    if(H5VL_object_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_OBJECT_GET_COMMENT, &loc_params, buf, bufsize, &ret_value) < 0)
-        HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "unable to get comment value")
+    if(H5VL_object_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_OBJECT_GET_COMMENT, &loc_params, buf, bufsize, &op_ret) < 0)
+        HGOTO_ERROR(H5E_SYM, H5E_CANTGET, -1, "unable to get comment value")
+
+    /* Set return value */
+    ret_value = (int)op_ret;
 
 done:
     FUNC_LEAVE_API(ret_value)
diff --git a/src/H5Gpublic.h b/src/H5Gpublic.h
index 58961ba..170b74d 100644
--- a/src/H5Gpublic.h
+++ b/src/H5Gpublic.h
@@ -37,10 +37,6 @@
 /* Public Macros */
 /*****************/
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 /*******************/
 /* Public Typedefs */
 /*******************/
@@ -62,21 +58,6 @@ typedef struct H5G_info_t {
     hbool_t     mounted;                /* Whether group has a file mounted on it */
 } H5G_info_t;
 
-/* Enumeration for native VOL connector group optional VOL operations */
-typedef enum H5VL_native_group_optional_t {
-    H5VL_NATIVE_GROUP_ITERATE_OLD,      /* HG5Giterate (deprecated routine) */
-    H5VL_NATIVE_GROUP_GET_OBJINFO       /* HG5Gget_objinfo (deprecated routine) */
-                                        /* (These two enum values should have an
-                                         *      "#ifndefH5_NO_DEPRECATED_SYMBOLS"
-                                         *      around them, but the compiler
-                                         *      complains about an empty enum
-                                         *      when deprecated symbols are
-                                         *      disabled currently.  When
-                                         *      another enum value is added,
-                                         *      please put the #ifdef around
-                                         *      these symbols.  QAK - 2018/12/06
-                                         */
-} H5VL_native_group_optional_t;
 
 /********************/
 /* Public Variables */
@@ -86,6 +67,10 @@ typedef enum H5VL_native_group_optional_t {
 /*********************/
 /* Public Prototypes */
 /*********************/
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 H5_DLL hid_t H5Gcreate2(hid_t loc_id, const char *name, hid_t lcpl_id,
     hid_t gcpl_id, hid_t gapl_id);
 H5_DLL hid_t H5Gcreate_anon(hid_t loc_id, hid_t gcpl_id, hid_t gapl_id);
diff --git a/src/H5L.c b/src/H5L.c
index 9506e7d..33e561a 100644
--- a/src/H5L.c
+++ b/src/H5L.c
@@ -1332,7 +1332,7 @@ H5Literate(hid_t group_id, H5_index_t idx_type, H5_iter_order_t order,
     loc_params.obj_type = H5I_get_type(group_id);
 
     /* Iterate over the links */
-    if((ret_value = H5VL_link_specific(vol_obj, &loc_params, H5VL_LINK_ITER, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, FALSE, idx_type, order, idx_p, op, op_data)) < 0)
+    if((ret_value = H5VL_link_specific(vol_obj, &loc_params, H5VL_LINK_ITER, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, (unsigned)FALSE, (int)idx_type, (int)order, idx_p, op, op_data)) < 0)
         HGOTO_ERROR(H5E_LINK, H5E_BADITER, FAIL, "link iteration failed")
 
 done:
diff --git a/src/H5O.c b/src/H5O.c
index ea88172..4e2f603 100644
--- a/src/H5O.c
+++ b/src/H5O.c
@@ -38,6 +38,8 @@
 #include "H5Lprivate.h"         /* Links                                    */
 #include "H5Opkg.h"             /* Object headers                           */
 
+#include "H5VLnative_private.h" /* Native VOL connector                     */
+
 
 /****************/
 /* Local Macros */
@@ -971,7 +973,7 @@ H5Ovisit2(hid_t obj_id, H5_index_t idx_type, H5_iter_order_t order,
     loc_params.obj_type     = H5I_get_type(obj_id);
 
     /* Visit the objects */
-    if((ret_value = H5VL_object_specific(vol_obj, &loc_params, H5VL_OBJECT_VISIT, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, idx_type, order, op, op_data, fields)) < 0)
+    if((ret_value = H5VL_object_specific(vol_obj, &loc_params, H5VL_OBJECT_VISIT, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, (int)idx_type, (int)order, op, op_data, fields)) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_BADITER, FAIL, "object iteration failed")
 
 done:
@@ -1055,7 +1057,7 @@ H5Ovisit_by_name2(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     loc_params.obj_type                     = H5I_get_type(loc_id);
 
     /* Visit the objects */
-    if((ret_value = H5VL_object_specific(vol_obj, &loc_params, H5VL_OBJECT_VISIT, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, idx_type, order, op, op_data, fields)) < 0)
+    if((ret_value = H5VL_object_specific(vol_obj, &loc_params, H5VL_OBJECT_VISIT, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, (int)idx_type, (int)order, op, op_data, fields)) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_BADITER, FAIL, "object iteration failed")
 
 done:
diff --git a/src/H5Odeprec.c b/src/H5Odeprec.c
index 56b0c05..7aefc67 100644
--- a/src/H5Odeprec.c
+++ b/src/H5Odeprec.c
@@ -37,6 +37,8 @@
 #include "H5Iprivate.h"         /* IDs                                      */
 #include "H5Opkg.h"             /* Object headers                           */
 
+#include "H5VLnative_private.h" /* Native VOL connector                     */
+
 
 /****************/
 /* Local Macros */
@@ -289,7 +291,7 @@ H5Ovisit1(hid_t obj_id, H5_index_t idx_type, H5_iter_order_t order,
     loc_params.obj_type     = H5I_get_type(obj_id);
 
     /* Visit the objects */
-    if((ret_value = H5VL_object_specific(vol_obj, &loc_params, H5VL_OBJECT_VISIT, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, idx_type, order, op, op_data, H5O_INFO_ALL)) < 0)
+    if((ret_value = H5VL_object_specific(vol_obj, &loc_params, H5VL_OBJECT_VISIT, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, (int)idx_type, (int)order, op, op_data, H5O_INFO_ALL)) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_BADITER, FAIL, "object visitation failed")
 
 done:
@@ -368,7 +370,7 @@ H5Ovisit_by_name1(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     loc_params.obj_type                     = H5I_get_type(loc_id);
 
     /* Visit the objects */
-    if((ret_value = H5VL_object_specific(vol_obj, &loc_params, H5VL_OBJECT_VISIT, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, idx_type, order, op, op_data, H5O_INFO_ALL)) < 0)
+    if((ret_value = H5VL_object_specific(vol_obj, &loc_params, H5VL_OBJECT_VISIT, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, (int)idx_type, (int)order, op, op_data, H5O_INFO_ALL)) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_BADITER, FAIL, "object visitation failed")
 
 done:
diff --git a/src/H5Oint.c b/src/H5Oint.c
index a97a2fd..2503eb7 100644
--- a/src/H5Oint.c
+++ b/src/H5Oint.c
@@ -83,7 +83,6 @@ static herr_t H5O__visit_cb(hid_t group, const char *name, const H5L_info_t *lin
     void *_udata);
 static const H5O_obj_class_t *H5O__obj_class_real(const H5O_t *oh);
 
-
 /*********************/
 /* Package Variables */
 /*********************/
@@ -277,99 +276,183 @@ done:
  *		matzke@llnl.gov
  *		Aug  5 1997
  *
+ * Changes:     2018 August 17
+ *              Jacob Smith 
+ *              Refactor out the operations into two separate steps --
+ *              preparation and application -- to facilitate overriding the
+ *              library-default size allocated for the object header. This
+ *              function is retained as a wrapper, to minimize changes to
+ *              unaffected calling functions.
+ *
  *-------------------------------------------------------------------------
  */
 herr_t
-H5O_create(H5F_t *f, size_t size_hint, size_t initial_rc, hid_t ocpl_id,
-    H5O_loc_t *loc/*out*/)
+H5O_create(H5F_t *f, size_t size_hint, size_t initial_rc, hid_t ocpl_id, H5O_loc_t *loc /*out*/)
 {
-    H5P_genplist_t  *oc_plist;          /* Object creation property list */
-    H5O_t      *oh = NULL;              /* Object header created */
-    haddr_t     oh_addr;                /* Address of initial object header */
-    size_t      oh_size;                /* Size of initial object header */
-    uint8_t	oh_flags;		/* Object header's initial status flags */
-    unsigned    insert_flags = H5AC__NO_FLAGS_SET; /* Flags for inserting object header into cache */
-    hbool_t     store_msg_crt_idx;      /* Whether to always store message creation indices for this file */
-    herr_t      ret_value = SUCCEED;    /* return value */
+    H5O_t  *oh        = NULL;
+    herr_t  ret_value = SUCCEED;
 
     FUNC_ENTER_NOAPI(FAIL)
 
-    /* check args */
     HDassert(f);
     HDassert(loc);
     HDassert(TRUE == H5P_isa_class(ocpl_id, H5P_OBJECT_CREATE));
 
+    /* create object header in freelist
+     * header version is set internally
+     */
+    oh = H5O__create_ohdr(f, ocpl_id);
+    if(NULL == oh)
+        HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, FAIL, "Can't instantiate object header")
+
+    /* apply object header information to file
+     */
+    if(H5O__apply_ohdr(f, oh, ocpl_id, size_hint, initial_rc, loc) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, FAIL, "Can't apply object header to file")
+
+done:
+    if((FAIL == ret_value) && (NULL != oh) && (H5O__free(oh) < 0))
+        HDONE_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "can't delete object header")
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5O_create() */
+
+
+/*-----------------------------------------------------------------------------
+ * Function:   H5O__create_ohdr
+ *
+ * Purpose:    Create the object header, set version and flags.
+ *
+ * Return:     Success: Pointer to the newly-crated header object.
+ *             Failure: NULL
+ *
+ * Programmer: Jacob Smith
+ *             2018 August 17 
+ *
+ *-----------------------------------------------------------------------------
+ */
+H5O_t *
+H5O__create_ohdr(H5F_t *f, hid_t ocpl_id)
+{
+    H5P_genplist_t *oc_plist;
+    H5O_t          *oh = NULL;        /* Object header in Freelist */
+    uint8_t         oh_flags;         /* Initial status flags */
+    H5O_t          *ret_value = NULL;
+
+    FUNC_ENTER_NOAPI(NULL)
+
+    HDassert(f);
+    HDassert(TRUE == H5P_isa_class(ocpl_id, H5P_OBJECT_CREATE));
+
     /* Check for invalid access request */
     if(0 == (H5F_INTENT(f) & H5F_ACC_RDWR))
-        HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, FAIL, "no write intent on file")
+        HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, NULL, "no write intent on file")
 
-    /* Make certain we allocate at least a reasonable size for the object header */
-    size_hint = H5O_ALIGN_F(f, MAX(H5O_MIN_SIZE, size_hint));
+    oh = H5FL_CALLOC(H5O_t);
+    if(NULL == oh)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
 
-    /* Get the property list */
-    if(NULL == (oc_plist = (H5P_genplist_t *)H5I_object(ocpl_id)))
-        HGOTO_ERROR(H5E_PLIST, H5E_BADTYPE, FAIL, "not a property list")
+    oc_plist = (H5P_genplist_t *)H5I_object(ocpl_id);
+    if(NULL == oc_plist)
+        HGOTO_ERROR(H5E_PLIST, H5E_BADTYPE, NULL, "not a property list")
 
     /* Get any object header status flags set by properties */
     if(H5P_get(oc_plist, H5O_CRT_OHDR_FLAGS_NAME, &oh_flags) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get object header flags")
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get object header flags")
 
-    /* Allocate the object header and zero out header fields */
-    if(NULL == (oh = H5FL_CALLOC(H5O_t)))
-        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed")
+    if(H5O_set_version(f, oh, oh_flags, H5F_STORE_MSG_CRT_IDX(f)) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, NULL, "can't set version of object header")
+
+    oh->flags = oh_flags;
+
+    ret_value = oh;
+
+done:
+    if((NULL == ret_value) && (NULL != oh) && (H5O__free(oh) < 0))
+        HDONE_ERROR(H5E_OHDR, H5E_CANTFREE, NULL, "can't delete object header")
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5O__create_ohdr() */
 
-    /* Initialize file-specific information for object header */
-    store_msg_crt_idx = H5F_STORE_MSG_CRT_IDX(f);
+
+/*-----------------------------------------------------------------------------
+ * Function:   H5O__apply_ohdr
+ *
+ * Purpose:    Initialize and set the object header in the file.
+ *             Record some information at `loc_out`.
+ *
+ * Return:     Success: SUCCEED (0) (non-negative value)
+ *             Failure: FAIL (-1) (negative value)
+ *
+ * Programmer: Jacob Smith
+ *             2018 August 17
+ *
+ *-----------------------------------------------------------------------------
+ */
+herr_t
+H5O__apply_ohdr(H5F_t *f, H5O_t *oh, hid_t ocpl_id, size_t size_hint, size_t initial_rc, H5O_loc_t *loc_out)
+{
+    haddr_t         oh_addr;
+    size_t          oh_size;
+    H5P_genplist_t *oc_plist     = NULL;
+    unsigned        insert_flags = H5AC__NO_FLAGS_SET;
+    herr_t          ret_value    = SUCCEED;
 
-    if(H5O_set_version(f, oh, oh_flags, store_msg_crt_idx) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set version of objecdt header")
+    FUNC_ENTER_NOAPI(FAIL)
+
+    HDassert(f);
+    HDassert(loc_out);
+    HDassert(oh);
+    HDassert(TRUE == H5P_isa_class(ocpl_id, H5P_OBJECT_CREATE));
+
+    /* Allocate at least a reasonable size for the object header */
+    size_hint = H5O_ALIGN_F(f, MAX(H5O_MIN_SIZE, size_hint));
 
     oh->sizeof_size = H5F_SIZEOF_SIZE(f);
     oh->sizeof_addr = H5F_SIZEOF_ADDR(f);
-    oh->swmr_write = !!(H5F_INTENT(f) & H5F_ACC_SWMR_WRITE);
+    oh->swmr_write = !!(H5F_INTENT(f) & H5F_ACC_SWMR_WRITE); /* funky cast */
+
 #ifdef H5O_ENABLE_BAD_MESG_COUNT
     /* Check whether the "bad message count" property is set */
-    if(H5P_exist_plist(oc_plist, H5O_BAD_MESG_COUNT_NAME) > 0) {
-        /* Retrieve bad message count flag */
+    if(0 < H5P_exist_plist(oc_plist, H5O_BAD_MESG_COUNT_NAME))
+        /* Get bad message count flag -- from property list */
         if(H5P_get(oc_plist, H5O_BAD_MESG_COUNT_NAME, &oh->store_bad_mesg_count) < 0)
             HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "can't get bad message count flag")
-    }
 #endif /* H5O_ENABLE_BAD_MESG_COUNT */
 
     /* Create object header proxy if doing SWMR writes */
     if(oh->swmr_write) {
-        /* Create virtual entry, for use as proxy */
-        if(NULL == (oh->proxy = H5AC_proxy_entry_create()))
+        oh->proxy = H5AC_proxy_entry_create();
+        if(NULL == oh->proxy)
             HGOTO_ERROR(H5E_OHDR, H5E_CANTCREATE, FAIL, "can't create object header proxy")
-    }
-    else
+    } else {
         oh->proxy = NULL;
+    }
 
-    /* Set initial status flags */
-    oh->flags = oh_flags;
+    oc_plist = (H5P_genplist_t *)H5I_object(ocpl_id);
+    if(NULL == oc_plist)
+        HGOTO_ERROR(H5E_PLIST, H5E_BADTYPE, FAIL, "not a property list")
 
     /* Initialize version-specific fields */
     if(oh->version > H5O_VERSION_1) {
-        /* Initialize all time fields with current time, if we are storing them */
+        /* Initialize all time fields */
         if(oh->flags & H5O_HDR_STORE_TIMES)
             oh->atime = oh->mtime = oh->ctime = oh->btime = H5_now();
         else
             oh->atime = oh->mtime = oh->ctime = oh->btime = 0;
 
-        /* Make certain attribute creation order tracking is enabled if
-         *      attributes can be shared in this file.
-         */
-        if(store_msg_crt_idx)
+        if(H5F_STORE_MSG_CRT_IDX(f))
+            /* flag to record message creation indices */
             oh->flags |= H5O_HDR_ATTR_CRT_ORDER_TRACKED;
 
-        /* Retrieve attribute storage phase change values from property list */
+        /* Get attribute storage phase change values -- from property list */
         if(H5P_get(oc_plist, H5O_CRT_ATTR_MAX_COMPACT_NAME, &oh->max_compact) < 0)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get max. # of compact attributes")
         if(H5P_get(oc_plist, H5O_CRT_ATTR_MIN_DENSE_NAME, &oh->min_dense) < 0)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get min. # of dense attributes")
 
         /* Check for non-default attribute storage phase change values */
-        if(oh->max_compact != H5O_CRT_ATTR_MAX_COMPACT_DEF || oh->min_dense != H5O_CRT_ATTR_MIN_DENSE_DEF)
+        if(H5O_CRT_ATTR_MAX_COMPACT_DEF != oh->max_compact  || H5O_CRT_ATTR_MIN_DENSE_DEF != oh->min_dense )
             oh->flags |= H5O_HDR_ATTR_STORE_PHASE_CHANGE;
 
         /* Determine correct value for chunk #0 size bits */
@@ -383,23 +466,25 @@ H5O_create(H5F_t *f, size_t size_hint, size_t initial_rc, hid_t ocpl_id,
             oh->flags |= H5O_HDR_CHUNK0_4;
         else if(size_hint > 255)
             oh->flags |= H5O_HDR_CHUNK0_2;
-    } /* end if */
-    else {
+    } else {
         /* Reset unused time fields */
         oh->atime = oh->mtime = oh->ctime = oh->btime = 0;
-    } /* end else */
+    } /* end if/else header version >1 */
 
     /* Compute total size of initial object header */
     /* (i.e. object header prefix and first chunk) */
     oh_size = (size_t)H5O_SIZEOF_HDR(oh) + size_hint;
 
     /* Allocate disk space for header and first chunk */
-    if(HADDR_UNDEF == (oh_addr = H5MF_alloc(f, H5FD_MEM_OHDR, (hsize_t)oh_size)))
+    oh_addr = H5MF_alloc(f, H5FD_MEM_OHDR, (hsize_t)oh_size);
+    if(HADDR_UNDEF == oh_addr)
         HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "file allocation failed for object header")
 
     /* Create the chunk list */
-    oh->nchunks = oh->alloc_nchunks = 1;
-    if(NULL == (oh->chunk = H5FL_SEQ_MALLOC(H5O_chunk_t, (size_t)oh->alloc_nchunks)))
+    oh->nchunks = 1;
+    oh->alloc_nchunks = 1;
+    oh->chunk = H5FL_SEQ_MALLOC(H5O_chunk_t, (size_t)oh->alloc_nchunks);
+    if(NULL == oh->chunk)
         HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed")
 
     /* Initialize the first chunk */
@@ -409,25 +494,27 @@ H5O_create(H5F_t *f, size_t size_hint, size_t initial_rc, hid_t ocpl_id,
 
     /* Allocate enough space for the first chunk */
     /* (including space for serializing the object header prefix */
-    if(NULL == (oh->chunk[0].image = H5FL_BLK_CALLOC(chunk_image, oh_size)))
+    oh->chunk[0].image = H5FL_BLK_CALLOC(chunk_image, oh_size);
+    if(NULL == oh->chunk[0].image)
         HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed")
     oh->chunk[0].chunk_proxy = NULL;
 
     /* Put magic # for object header in first chunk */
-    if(oh->version > H5O_VERSION_1)
+    if(H5O_VERSION_1 < oh->version)
         HDmemcpy(oh->chunk[0].image, H5O_HDR_MAGIC, (size_t)H5_SIZEOF_MAGIC);
 
     /* Create the message list */
     oh->nmesgs = 1;
     oh->alloc_nmesgs = H5O_NMESGS;
-    if(NULL == (oh->mesg = H5FL_SEQ_CALLOC(H5O_mesg_t, oh->alloc_nmesgs)))
+    oh->mesg = H5FL_SEQ_CALLOC(H5O_mesg_t, oh->alloc_nmesgs);
+    if(NULL == oh->mesg)
         HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed")
 
-    /* Initialize the initial "null" message, covering the entire first chunk */
+    /* Initialize the initial "null" message; covers the entire first chunk */
     oh->mesg[0].type = H5O_MSG_NULL;
     oh->mesg[0].dirty = TRUE;
     oh->mesg[0].native = NULL;
-    oh->mesg[0].raw = oh->chunk[0].image + (H5O_SIZEOF_HDR(oh) - H5O_SIZEOF_CHKSUM_OH(oh)) + H5O_SIZEOF_MSGHDR_OH(oh);
+    oh->mesg[0].raw = oh->chunk[0].image + H5O_SIZEOF_HDR(oh) - H5O_SIZEOF_CHKSUM_OH(oh) + H5O_SIZEOF_MSGHDR_OH(oh);
     oh->mesg[0].raw_size = size_hint - (size_t)H5O_SIZEOF_MSGHDR_OH(oh);
     oh->mesg[0].chunkno = 0;
 
@@ -452,20 +539,15 @@ H5O_create(H5F_t *f, size_t size_hint, size_t initial_rc, hid_t ocpl_id,
     H5_END_TAG
 
     /* Set up object location */
-    loc->file = f;
-    loc->addr = oh_addr;
+    loc_out->file = f;
+    loc_out->addr = oh_addr;
 
-    /* Open it */
-    if(H5O_open(loc) < 0)
+    if(H5O_open(loc_out) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, FAIL, "unable to open object header")
 
 done:
-    if(ret_value < 0 && oh)
-        if(H5O__free(oh) < 0)
-            HDONE_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to destroy object header data")
-
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5O_create() */
+    FUNC_LEAVE_NOAPI(ret_value);
+} /* H5O__apply_ohdr() */
 
 
 /*-------------------------------------------------------------------------
@@ -2420,6 +2502,63 @@ H5O_get_oh_addr(const H5O_t *oh)
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5O_get_oh_flags
+ *
+ * Programmer:	Jacob Smith
+ *		2018 August 17
+ *
+ *-------------------------------------------------------------------------
+ */
+uint8_t
+H5O_get_oh_flags(const H5O_t *oh)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+    HDassert(oh);
+    FUNC_LEAVE_NOAPI(oh->flags); /* flags can be 0 */
+} /* H5O_get_oh_flags() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5O_get_oh_mtime
+ *
+ * Purpose:	Retrieve an object's modification time. Assumes that the
+ *              caller has verified that accessing this variable is appropriate
+ *              to the header in question.
+ *
+ * Programmer:	Jacob Smith
+ *		2018 August 17
+ *
+ *-------------------------------------------------------------------------
+ */
+time_t
+H5O_get_oh_mtime(const H5O_t *oh)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+    HDassert(oh);
+    HDassert(oh->mtime);
+    FUNC_LEAVE_NOAPI(oh->mtime);
+} /* H5O_get_oh_mtime() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5O_get_oh_version
+ *
+ * Programmer:	Jacob Smith
+ *		2018 August 17
+ *
+ *-------------------------------------------------------------------------
+ */
+uint8_t
+H5O_get_oh_version(const H5O_t *oh)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+    HDassert(oh);
+    HDassert(oh->version);
+    FUNC_LEAVE_NOAPI(oh->version);
+} /* H5O_get_oh_version() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5O_get_rc_and_type
  *
  * Purpose:	Retrieve an object's reference count and type
diff --git a/src/H5Oprivate.h b/src/H5Oprivate.h
index 7ed9e26..e0926e2 100644
--- a/src/H5Oprivate.h
+++ b/src/H5Oprivate.h
@@ -121,8 +121,14 @@ typedef struct H5O_mesg_t H5O_mesg_t;
 /* If the module using this macro is allowed access to the private variables, access them directly */
 #ifdef H5O_MODULE
 #define H5O_OH_GET_ADDR(O)    ((O)->chunk[0].addr)
+#define H5O_OH_GET_VERSION(O) ((O)->version)
+#define H5O_OH_GET_FLAGS(O)   ((O)->flags)
+#define H5O_OH_GET_MTIME(O)   ((O)->mtime)
 #else /* H5O_MODULE */
 #define H5O_OH_GET_ADDR(O)    (H5O_get_oh_addr(O))
+#define H5O_OH_GET_VERSION(O) (H5O_get_oh_version(O))
+#define H5O_OH_GET_FLAGS(O)   (H5O_get_oh_flags(O))
+#define H5O_OH_GET_MTIME(O)   (H5O_get_oh_mtime(O))
 #endif /* H5O_MODULE */
 
 /* Set the fields in a shared message structure */
@@ -865,6 +871,9 @@ struct H5P_genplist_t;
 H5_DLL herr_t H5O_init(void);
 H5_DLL herr_t H5O_create(H5F_t *f, size_t size_hint, size_t initial_rc,
     hid_t ocpl_id, H5O_loc_t *loc/*out*/);
+H5_DLL H5O_t *H5O__create_ohdr(H5F_t *f, hid_t ocpl_id);
+H5_DLL herr_t H5O__apply_ohdr(H5F_t *f, H5O_t *oh, hid_t ocpl_id,
+    size_t size_hint, size_t initial_rc, H5O_loc_t *loc_out);
 H5_DLL herr_t H5O_open(H5O_loc_t *loc);
 H5_DLL void *H5O_open_by_idx(const H5G_loc_t *loc, const char *name,
     H5_index_t idx_type, H5_iter_order_t order, hsize_t n, H5I_type_t *opened_type/*out*/);
@@ -891,6 +900,9 @@ H5_DLL void *H5O_open_name(const H5G_loc_t *loc, const char *name, H5I_type_t *o
 H5_DLL herr_t H5O_get_nlinks(const H5O_loc_t *loc, hsize_t *nlinks);
 H5_DLL void *H5O_obj_create(H5F_t *f, H5O_type_t obj_type, void *crt_info, H5G_loc_t *obj_loc);
 H5_DLL haddr_t H5O_get_oh_addr(const H5O_t *oh);
+H5_DLL uint8_t H5O_get_oh_flags(const H5O_t *oh);
+H5_DLL time_t H5O_get_oh_mtime(const H5O_t *oh);
+H5_DLL uint8_t H5O_get_oh_version(const H5O_t *oh);
 H5_DLL herr_t H5O_get_rc_and_type(const H5O_loc_t *oloc, unsigned *rc, H5O_type_t *otype);
 H5_DLL H5AC_proxy_entry_t *H5O_get_proxy(const H5O_t *oh);
 
diff --git a/src/H5Opublic.h b/src/H5Opublic.h
index fe0c72d..c868e72 100644
--- a/src/H5Opublic.h
+++ b/src/H5Opublic.h
@@ -150,25 +150,19 @@ typedef enum H5O_mcdt_search_ret_t {
 /* Callback to invoke when completing the search for a matching committed datatype from the committed dtype list */
 typedef H5O_mcdt_search_ret_t (*H5O_mcdt_search_cb_t)(void *op_data);
 
-/* Enumeration for native VOL connector object optional VOL operations */
-typedef enum H5VL_native_object_optional_t {
-    H5VL_NATIVE_OBJECT_GET_COMMENT,         /* H5G|H5Oget_comment, H5Oget_comment_by_name   */
-    H5VL_NATIVE_OBJECT_GET_INFO,            /* H5Oget_info(_by_idx, _by_name)(2?)           */
-    H5VL_NATIVE_OBJECT_SET_COMMENT          /* H5G|H5Oset_comment, H5Oset_comment_by_name   */
-} H5VL_native_object_optional_t;
 
 /********************/
 /* Public Variables */
 /********************/
 
 
+/*********************/
+/* Public Prototypes */
+/*********************/
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-/*********************/
-/* Public Prototypes */
-/*********************/
 H5_DLL hid_t H5Oopen(hid_t loc_id, const char *name, hid_t lapl_id);
 H5_DLL hid_t H5Oopen_by_addr(hid_t loc_id, haddr_t addr);
 H5_DLL hid_t H5Oopen_by_idx(hid_t loc_id, const char *group_name,
diff --git a/src/H5PLint.c b/src/H5PLint.c
index ded315a..8dec14b 100644
--- a/src/H5PLint.c
+++ b/src/H5PLint.c
@@ -311,6 +311,7 @@ H5PL__open(const char *path, H5PL_type_t type, const H5PL_key_t *key,
     hbool_t *success, const void **plugin_info)
 {
     H5PL_HANDLE             handle = NULL;
+    H5PL_get_plugin_type_t  get_plugin_type = NULL;
     H5PL_get_plugin_info_t  get_plugin_info = NULL;
     herr_t                  ret_value = SUCCEED;
 
@@ -333,12 +334,22 @@ H5PL__open(const char *path, H5PL_type_t type, const H5PL_key_t *key,
         HGOTO_DONE(SUCCEED)
     }
 
+    /* Return a handle for the function H5PLget_plugin_type in the dynamic library.
+     * The plugin library is supposed to define this function.
+     */
+    if (NULL == (get_plugin_type = (H5PL_get_plugin_type_t)H5PL_GET_LIB_FUNC(handle, "H5PLget_plugin_type")))
+        HGOTO_DONE(SUCCEED)
+
     /* Return a handle for the function H5PLget_plugin_info in the dynamic library.
-     * The plugin library is suppose to define this function.
+     * The plugin library is supposed to define this function.
      */
     if (NULL == (get_plugin_info = (H5PL_get_plugin_info_t)H5PL_GET_LIB_FUNC(handle, "H5PLget_plugin_info")))
         HGOTO_DONE(SUCCEED)
 
+    /* Check the plugin type and return if it doesn't match the one passed in */
+    if(type != (H5PL_type_t)(*get_plugin_type)())
+        HGOTO_DONE(SUCCEED)
+
     /* Get the plugin information */
     switch (type) {
         case H5PL_TYPE_FILTER:
@@ -364,7 +375,7 @@ H5PL__open(const char *path, H5PL_type_t type, const H5PL_key_t *key,
 
             /* Get the plugin info */
             if(NULL == (cls = (const H5VL_class_t *)(*get_plugin_info)()))
-                HGOTO_ERROR(H5E_PLUGIN, H5E_CANTGET, FAIL, "can't get VOL driver info from plugin")
+                HGOTO_ERROR(H5E_PLUGIN, H5E_CANTGET, FAIL, "can't get VOL connector info from plugin")
 
             /* Which kind of key are we looking for? */
             if(key->vol.kind == H5VL_GET_CONNECTOR_BY_NAME) {
diff --git a/src/H5PLpkg.h b/src/H5PLpkg.h
index c3ad8f5..8c2367f 100644
--- a/src/H5PLpkg.h
+++ b/src/H5PLpkg.h
@@ -79,6 +79,7 @@
     /* maximum size for expanding env vars */
 #   define H5PL_EXPAND_BUFFER_SIZE 32767
 
+    typedef H5PL_type_t(__cdecl *H5PL_get_plugin_type_t)(void);
     typedef const void *(__cdecl *H5PL_get_plugin_info_t)(void);
 
 #else /* H5_HAVE_WIN32_API */
@@ -105,6 +106,7 @@
     /* Clear error */
 #   define H5PL_CLR_ERROR HERROR(H5E_PLUGIN, H5E_CANTGET, "can't dlopen:%s", dlerror())
 
+    typedef H5PL_type_t(*H5PL_get_plugin_type_t)(void);
     typedef const void *(*H5PL_get_plugin_info_t)(void);
 #endif /* H5_HAVE_WIN32_API */
 
diff --git a/src/H5Pdcpl.c b/src/H5Pdcpl.c
index a5a16bb..b85f105 100644
--- a/src/H5Pdcpl.c
+++ b/src/H5Pdcpl.c
@@ -117,6 +117,11 @@
 #define H5D_CRT_EXT_FILE_LIST_COPY H5P__dcrt_ext_file_list_copy
 #define H5D_CRT_EXT_FILE_LIST_CMP  H5P__dcrt_ext_file_list_cmp
 #define H5D_CRT_EXT_FILE_LIST_CLOSE H5P__dcrt_ext_file_list_close
+/* Definitions for dataset object header minimization */
+#define H5D_CRT_MIN_DSET_HDR_SIZE_SIZE sizeof(hbool_t)
+#define H5D_CRT_MIN_DSET_HDR_SIZE_DEF  FALSE
+#define H5D_CRT_MIN_DSET_HDR_SIZE_ENC  H5P__encode_hbool_t
+#define H5D_CRT_MIN_DSET_HDR_SIZE_DEC  H5P__decode_hbool_t
 
 
 /******************/
@@ -209,6 +214,7 @@ static const H5O_layout_t H5D_def_layout_g = H5D_CRT_LAYOUT_DEF;        /* Defau
 static const H5O_fill_t H5D_def_fill_g = H5D_CRT_FILL_VALUE_DEF;        /* Default fill value */
 static const unsigned H5D_def_alloc_time_state_g = H5D_CRT_ALLOC_TIME_STATE_DEF;  /* Default allocation time state */
 static const H5O_efl_t H5D_def_efl_g = H5D_CRT_EXT_FILE_LIST_DEF;                 /* Default external file list */
+static const unsigned H5O_ohdr_min_g = H5D_CRT_MIN_DSET_HDR_SIZE_DEF; /* Default object header minimization */
 
 /* Defaults for each type of layout */
 #ifdef H5_HAVE_C99_DESIGNATED_INITIALIZER
@@ -271,6 +277,12 @@ H5P__dcrt_reg_prop(H5P_genclass_t *pclass)
             H5D_CRT_EXT_FILE_LIST_DEL, H5D_CRT_EXT_FILE_LIST_COPY, H5D_CRT_EXT_FILE_LIST_CMP, H5D_CRT_EXT_FILE_LIST_CLOSE) < 0)
        HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
 
+    /* Register the object header minimization property */
+    if(H5P__register_real(pclass, H5D_CRT_MIN_DSET_HDR_SIZE_NAME, H5D_CRT_MIN_DSET_HDR_SIZE_SIZE, &H5O_ohdr_min_g,
+            NULL, NULL, NULL, H5D_CRT_MIN_DSET_HDR_SIZE_ENC, H5D_CRT_MIN_DSET_HDR_SIZE_DEC,
+            NULL, NULL, NULL, NULL) < 0)
+       HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
+
     /* Register the type ID property*/
     if(H5P__register_real(pclass, H5VL_PROP_DSET_TYPE_ID, sizeof(hid_t), &type_id, 
                          NULL, NULL, NULL, NULL, NULL, NULL, NULL, H5P_ignore_cmp, NULL) < 0)
@@ -3749,3 +3761,95 @@ done:
     FUNC_LEAVE_API(ret_value)
 } /* end H5Pget_fill_time() */
 
+
+/*-----------------------------------------------------------------------------
+ * Function: H5Pget_dset_no_attrs_hint
+ *
+ * Purpose:
+ *
+ *     Access the flag for whether or not datasets created by the given dcpl
+ *     will be created with a "minimized" object header.
+ *
+ * Return:
+ *
+ *     Failure: Negative value (FAIL)
+ *     Success: Non-negative value (SUCCEED)
+ *
+ * Programmer: Jacob Smith
+ *             2018 August 14
+ *
+ * Modifications: None.
+ *
+ *-----------------------------------------------------------------------------
+ */
+herr_t
+H5Pget_dset_no_attrs_hint(hid_t dcpl_id, hbool_t *minimize)
+{
+    hbool_t         setting   = FALSE;
+    H5P_genplist_t *plist     = NULL;
+    herr_t          ret_value = SUCCEED;
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE2("e", "i*b", dcpl_id, minimize);
+
+    if(NULL == minimize)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "receiving pointer cannot be NULL")
+
+    plist = H5P_object_verify(dcpl_id, H5P_DATASET_CREATE);
+    if(NULL == plist)
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
+
+    if(H5P_peek(plist, H5D_CRT_MIN_DSET_HDR_SIZE_NAME, &setting) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get dset oh minimize flag value")
+
+    *minimize = setting;
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* H5Pget_dset_no_attrs_hint() */
+
+
+/*-----------------------------------------------------------------------------
+ * Function: H5Pset_dset_no_attrs_hint
+ *
+ * Purpose:
+ *
+ *     Set the dcpl to minimize (or explicitly to not minimized) dataset object
+ *     headers upon creation.
+ *
+ * Return:
+ *
+ *     Failure: Negative value (FAIL)
+ *     Success: Non-negative value (SUCCEED)
+ *
+ * Programmer: Jacob Smith
+ *             2018 August 14
+ *
+ * Modifications: None.
+ *
+ *-----------------------------------------------------------------------------
+ */
+herr_t
+H5Pset_dset_no_attrs_hint(hid_t dcpl_id, hbool_t minimize)
+{
+    H5P_genplist_t *plist     = NULL;
+    hbool_t         prev_set  = FALSE;
+    herr_t          ret_value = SUCCEED;
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE2("e", "ib", dcpl_id, minimize);
+
+    plist = H5P_object_verify(dcpl_id, H5P_DATASET_CREATE);
+    if(NULL == plist)
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
+
+    if(H5P_peek(plist, H5D_CRT_MIN_DSET_HDR_SIZE_NAME, &prev_set) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get extant dset oh minimize flag value")
+
+    if(H5P_poke(plist, H5D_CRT_MIN_DSET_HDR_SIZE_NAME, &minimize) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't get dset oh minimize flag value")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* H5Pset_dset_no_attrs_hint() */
+
diff --git a/src/H5Pfapl.c b/src/H5Pfapl.c
index 923c792..452ea3f 100644
--- a/src/H5Pfapl.c
+++ b/src/H5Pfapl.c
@@ -49,7 +49,7 @@
 #endif
 
 /* Includes needed to set default VOL connector */
-#include "H5VLnative.h"         /* Native VOL connector                 */
+#include "H5VLnative_private.h" /* Native VOL connector                     */
 
 
 /****************/
@@ -177,16 +177,6 @@
 #define H5F_ACS_FILE_IMAGE_INFO_COPY            H5P__facc_file_image_info_copy
 #define H5F_ACS_FILE_IMAGE_INFO_CMP             H5P__facc_file_image_info_cmp
 #define H5F_ACS_FILE_IMAGE_INFO_CLOSE           H5P__facc_file_image_info_close
-/* Definition of core VFD write tracking flag */
-#define H5F_ACS_CORE_WRITE_TRACKING_FLAG_SIZE   sizeof(hbool_t)
-#define H5F_ACS_CORE_WRITE_TRACKING_FLAG_DEF    FALSE
-#define H5F_ACS_CORE_WRITE_TRACKING_FLAG_ENC    H5P__encode_hbool_t
-#define H5F_ACS_CORE_WRITE_TRACKING_FLAG_DEC    H5P__decode_hbool_t
-/* Definition of core VFD write tracking page size */
-#define H5F_ACS_CORE_WRITE_TRACKING_PAGE_SIZE_SIZE      sizeof(size_t)
-#define H5F_ACS_CORE_WRITE_TRACKING_PAGE_SIZE_DEF       524288
-#define H5F_ACS_CORE_WRITE_TRACKING_PAGE_SIZE_ENC       H5P__encode_size_t
-#define H5F_ACS_CORE_WRITE_TRACKING_PAGE_SIZE_DEC       H5P__decode_size_t
 /* Definition for # of metadata read attempts */
 #define H5F_ACS_METADATA_READ_ATTEMPTS_SIZE    sizeof(unsigned)
 #define H5F_ACS_METADATA_READ_ATTEMPTS_DEF         0
@@ -401,8 +391,6 @@ static const H5F_libver_t H5F_def_libver_high_bound_g = H5F_ACS_LIBVER_HIGH_BOUN
 static const hbool_t H5F_def_want_posix_fd_g = H5F_ACS_WANT_POSIX_FD_DEF;          /* Default setting for retrieving 'handle' from core VFD */
 static const unsigned H5F_def_efc_size_g = H5F_ACS_EFC_SIZE_DEF;                   /* Default external file cache size */
 static const H5FD_file_image_info_t H5F_def_file_image_info_g = H5F_ACS_FILE_IMAGE_INFO_DEF;                 /* Default file image info and callbacks */
-static const hbool_t H5F_def_core_write_tracking_flag_g = H5F_ACS_CORE_WRITE_TRACKING_FLAG_DEF;              /* Default setting for core VFD write tracking */
-static const size_t H5F_def_core_write_tracking_page_size_g = H5F_ACS_CORE_WRITE_TRACKING_PAGE_SIZE_DEF;     /* Default core VFD write tracking page size */
 static const unsigned H5F_def_metadata_read_attempts_g = H5F_ACS_METADATA_READ_ATTEMPTS_DEF;  /* Default setting for the # of metadata read attempts */
 static const H5F_object_flush_t H5F_def_object_flush_cb_g = H5F_ACS_OBJECT_FLUSH_CB_DEF;      /* Default setting for object flush callback */
 static const hbool_t H5F_def_clear_status_flags_g = H5F_ACS_CLEAR_STATUS_FLAGS_DEF;           /* Default to clear the superblock status_flags */
@@ -572,18 +560,6 @@ H5P__facc_reg_prop(H5P_genclass_t *pclass)
             H5F_ACS_FILE_IMAGE_INFO_DEL, H5F_ACS_FILE_IMAGE_INFO_COPY, H5F_ACS_FILE_IMAGE_INFO_CMP, H5F_ACS_FILE_IMAGE_INFO_CLOSE) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
 
-    /* Register the core VFD backing store write tracking flag */
-    if(H5P__register_real(pclass, H5F_ACS_CORE_WRITE_TRACKING_FLAG_NAME, H5F_ACS_CORE_WRITE_TRACKING_FLAG_SIZE, &H5F_def_core_write_tracking_flag_g,
-            NULL, NULL, NULL, H5F_ACS_CORE_WRITE_TRACKING_FLAG_ENC, H5F_ACS_CORE_WRITE_TRACKING_FLAG_DEC,
-            NULL, NULL, NULL, NULL) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
-
-    /* Register the size of the core VFD backing store page size */
-    if(H5P__register_real(pclass, H5F_ACS_CORE_WRITE_TRACKING_PAGE_SIZE_NAME, H5F_ACS_CORE_WRITE_TRACKING_PAGE_SIZE_SIZE, &H5F_def_core_write_tracking_page_size_g,
-            NULL, NULL, NULL, H5F_ACS_CORE_WRITE_TRACKING_PAGE_SIZE_ENC, H5F_ACS_CORE_WRITE_TRACKING_PAGE_SIZE_DEC,
-            NULL, NULL, NULL, NULL) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
-
     /* Register the # of read attempts */
     if(H5P__register_real(pclass, H5F_ACS_METADATA_READ_ATTEMPTS_NAME, H5F_ACS_METADATA_READ_ATTEMPTS_SIZE, &H5F_def_metadata_read_attempts_g,
             NULL, NULL, NULL, H5F_ACS_METADATA_READ_ATTEMPTS_ENC, H5F_ACS_METADATA_READ_ATTEMPTS_DEC,
@@ -3957,89 +3933,6 @@ H5P__facc_libver_type_dec(const void **_pp, void *_value)
     FUNC_LEAVE_NOAPI(SUCCEED)
 } /* end H5P__facc_libver_type_dec() */
 
-
-/*-------------------------------------------------------------------------
- * Function:    H5Pset_core_write_tracking
- *
- * Purpose:    Enables/disables core VFD write tracking and page
- *              aggregation size.
- *
- * Return:    Non-negative on success/Negative on failure
- *
- * Programmer:  Dana Robinson
- *              Tuesday, April 8, 2014
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5Pset_core_write_tracking(hid_t plist_id, hbool_t is_enabled, size_t page_size)
-{
-    H5P_genplist_t *plist;        /* Property list pointer */
-    herr_t ret_value = SUCCEED;   /* return value */
-
-    FUNC_ENTER_API(FAIL)
-    H5TRACE3("e", "ibz", plist_id, is_enabled, page_size);
-
-    /* The page size cannot be zero */
-    if(page_size == 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "page_size cannot be zero")
-
-    /* Get the plist structure */
-    if(NULL == (plist = H5P_object_verify(plist_id, H5P_FILE_ACCESS)))
-        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
-
-    /* Set values */
-    if(H5P_set(plist, H5F_ACS_CORE_WRITE_TRACKING_FLAG_NAME, &is_enabled) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set core VFD write tracking flag")
-    if(H5P_set(plist, H5F_ACS_CORE_WRITE_TRACKING_PAGE_SIZE_NAME, &page_size) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set core VFD write tracking page size")
-
-done:
-    FUNC_LEAVE_API(ret_value)
-} /* end H5Pset_core_write_tracking() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5Pget_core_write_tracking
- *
- * Purpose:    Gets information about core VFD write tracking and page
- *              aggregation size.
- *
- * Return:    Non-negative on success/Negative on failure
- *
- * Programmer:  Dana Robinson
- *              Tuesday, April 8, 2014
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5Pget_core_write_tracking(hid_t plist_id, hbool_t *is_enabled, size_t *page_size)
-{
-    H5P_genplist_t *plist;      /* Property list pointer */
-    herr_t ret_value = SUCCEED;   /* return value */
-
-    FUNC_ENTER_API(FAIL)
-    H5TRACE3("e", "i*b*z", plist_id, is_enabled, page_size);
-
-    /* Get the plist structure */
-    if(NULL == (plist = H5P_object_verify(plist_id, H5P_FILE_ACCESS)))
-        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
-
-    /* Get values */
-    if(is_enabled) {
-        if(H5P_get(plist, H5F_ACS_CORE_WRITE_TRACKING_FLAG_NAME, is_enabled) < 0)
-            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get core VFD write tracking flag")
-    } /* end if */
-
-    if(page_size) {
-        if(H5P_get(plist, H5F_ACS_CORE_WRITE_TRACKING_PAGE_SIZE_NAME, page_size) < 0)
-            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get core VFD write tracking page size")
-    } /* end if */
-
-done:
-    FUNC_LEAVE_API(ret_value)
-} /* end H5Pget_core_write_tracking() */
-
 
 /*-------------------------------------------------------------------------
  * Function:    H5Pset_metadata_read_attempts
diff --git a/src/H5Ppublic.h b/src/H5Ppublic.h
index 86c6687..2f094ea 100644
--- a/src/H5Ppublic.h
+++ b/src/H5Ppublic.h
@@ -412,6 +412,8 @@ H5_DLL herr_t H5Pget_alloc_time(hid_t plist_id, H5D_alloc_time_t
 H5_DLL herr_t H5Pset_fill_time(hid_t plist_id, H5D_fill_time_t fill_time);
 H5_DLL herr_t H5Pget_fill_time(hid_t plist_id, H5D_fill_time_t
     *fill_time/*out*/);
+H5_DLL herr_t H5Pget_dset_no_attrs_hint(hid_t dcpl_id, hbool_t *minimize);
+H5_DLL herr_t H5Pset_dset_no_attrs_hint(hid_t dcpl_id, hbool_t minimize);
 
 /* Dataset access property list (DAPL) routines */
 H5_DLL herr_t H5Pset_chunk_cache(hid_t dapl_id, size_t rdcc_nslots,
diff --git a/src/H5R.c b/src/H5R.c
index b7866b1..7d3686e 100644
--- a/src/H5R.c
+++ b/src/H5R.c
@@ -127,7 +127,7 @@ H5Rcreate(void *ref, hid_t loc_id, const char *name, H5R_type_t ref_type, hid_t
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTSET, FAIL, "can't set access property list info")
 
     /* Create reference */
-    if((ret_value = H5VL_object_specific(vol_obj, &loc_params, H5VL_REF_CREATE, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, ref, name, ref_type, space_id)) < 0)
+    if((ret_value = H5VL_object_specific(vol_obj, &loc_params, H5VL_REF_CREATE, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, ref, name, (int)ref_type, space_id)) < 0)
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTCREATE, FAIL, "unable to create reference")
 
 done:
@@ -257,7 +257,7 @@ H5Rget_region(hid_t id, H5R_type_t ref_type, const void *ref)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid file identifier")
 
     /* Get the dataspace with the correct region selected */
-    if(H5VL_object_get(vol_obj, &loc_params, H5VL_REF_GET_REGION, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &ret_value, ref_type, ref) < 0)
+    if(H5VL_object_get(vol_obj, &loc_params, H5VL_REF_GET_REGION, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &ret_value, (int)ref_type, ref) < 0)
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, H5I_INVALID_HID, "unable to retrieve dataspace")
 
 done:
@@ -314,7 +314,7 @@ H5Rget_obj_type2(hid_t id, H5R_type_t ref_type, const void *ref,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
 
     /* Get the object type */
-    if(H5VL_object_get(vol_obj, &loc_params, H5VL_REF_GET_TYPE, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, obj_type, ref_type, ref) < 0)
+    if(H5VL_object_get(vol_obj, &loc_params, H5VL_REF_GET_TYPE, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, obj_type, (int)ref_type, ref) < 0)
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, FAIL, "unable to determine object type")
 
 done:
@@ -381,7 +381,7 @@ H5Rget_name(hid_t id, H5R_type_t ref_type, const void *_ref, char *name,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, (-1), "invalid file identifier")
 
     /* Get name */
-    if(H5VL_object_get(vol_obj, &loc_params, H5VL_REF_GET_NAME, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &ret_value, name, size, ref_type, _ref) < 0)
+    if(H5VL_object_get(vol_obj, &loc_params, H5VL_REF_GET_NAME, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &ret_value, name, size, (int)ref_type, _ref) < 0)
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, (-1), "unable to determine object path")
 
 done:
diff --git a/src/H5Rdeprec.c b/src/H5Rdeprec.c
index 827506e..ab8d3b4 100644
--- a/src/H5Rdeprec.c
+++ b/src/H5Rdeprec.c
@@ -126,7 +126,7 @@ H5Rget_obj_type1(hid_t id, H5R_type_t ref_type, const void *ref)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5G_UNKNOWN, "invalid file identifier")
 
     /* Get the object information */
-    if(H5VL_object_get(vol_obj, &loc_params, H5VL_REF_GET_TYPE, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &obj_type, ref_type, ref) < 0)
+    if(H5VL_object_get(vol_obj, &loc_params, H5VL_REF_GET_TYPE, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &obj_type, (int)ref_type, ref) < 0)
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, H5G_UNKNOWN, "unable to determine object type")
 
     /* Set return value */
diff --git a/src/H5VL.c b/src/H5VL.c
index eedf68d..88d3d70 100644
--- a/src/H5VL.c
+++ b/src/H5VL.c
@@ -11,7 +11,7 @@
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 /*
- * Purpose:	The Virtual Object Layer as described in documentation.
+ * Purpose:     The Virtual Object Layer as described in documentation.
  *              The pupose is to provide an abstraction on how to access the
  *              underlying HDF5 container, whether in a local file with
  *              a specific file format, or remotely on other machines, etc...
@@ -295,7 +295,7 @@ H5VLregister_connector_by_value(H5VL_class_value_t value, hid_t vipl_id)
         const H5VL_class_t *cls;
 
         /* Try loading the connector */
-        key.vol.kind = H5VL_GET_CONNECTOR_BY_NAME;
+        key.vol.kind = H5VL_GET_CONNECTOR_BY_VALUE;
         key.vol.u.value = value;
         if(NULL == (cls = (const H5VL_class_t *)H5PL_load(H5PL_TYPE_VOL, &key)))
             HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, H5I_INVALID_HID, "unable to load VOL connector")
@@ -486,14 +486,11 @@ done:
 /*---------------------------------------------------------------------------
  * Function:    H5VLcmp_connector_cls
  *
- * Purpose:     Compares two connector classes
+ * Purpose:     Compares two connector classes (based on their value field)
  *
- * Return:      Success:    Non-negative, with *cmp set to positive if
- *		connector_id1 is greater than connector_id2, negative if connector_id2
- *		is greater than connector_id1 and zero if connector_id1 and connector_id2
- *		are equal.
+ * Return:      Success:    Non-negative, *cmp set to a value like strcmp
  *
- *              Failure:    Negative
+ *              Failure:    Negative, *cmp unset
  *
  *---------------------------------------------------------------------------
  */
diff --git a/src/H5VLint.c b/src/H5VLint.c
index 17dfc1f..8695a80 100644
--- a/src/H5VLint.c
+++ b/src/H5VLint.c
@@ -627,7 +627,7 @@ H5VL_register_connector(const void *_cls, hbool_t app_ref, hid_t vipl_id)
 done:
     if (ret_value < 0 && saved) {
         if (saved->name)
-            H5MM_xfree(saved->name);
+            H5MM_xfree((void *)(saved->name));  /* Casting away const OK -QAK */
 
         H5FL_FREE(H5VL_class_t, saved);
     }
@@ -881,7 +881,7 @@ done:
  *
  * Return:      Positive if VALUE1 is greater than VALUE2, negative if
  *              VALUE2 is greater than VALUE1 and zero if VALUE1 and
- *              VALUE2 are equal.
+ *              VALUE2 are equal (like strcmp).
  *
  *-------------------------------------------------------------------------
  */
diff --git a/src/H5VLnative.c b/src/H5VLnative.c
index 4e6af18..fe0fd4e 100644
--- a/src/H5VLnative.c
+++ b/src/H5VLnative.c
@@ -11,113 +11,25 @@
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 /*
- * Purpose:	The native VOL connector where access is to a single HDF5 file 
+ * Purpose:     The native VOL connector where access is to a single HDF5 file 
  *              using HDF5 VFDs. 
  */
 
-#define H5A_FRIEND              /* Suppress error about including H5Apkg    */
-#define H5D_FRIEND              /* Suppress error about including H5Dpkg    */
-#define H5F_FRIEND              /* Suppress error about including H5Fpkg    */
-#define H5G_FRIEND              /* Suppress error about including H5Gpkg    */
-#define H5L_FRIEND              /* Suppress error about including H5Lpkg    */
-#define H5O_FRIEND              /* Suppress error about including H5Opkg    */
-#define H5R_FRIEND              /* Suppress error about including H5Rpkg    */
-#define H5T_FRIEND              /* Suppress error about including H5Tpkg    */
-
-
 #include "H5private.h"          /* Generic Functions                        */
-#include "H5Apkg.h"             /* Attributes                               */
-#include "H5Dpkg.h"             /* Datasets                                 */
 #include "H5Eprivate.h"         /* Error handling                           */
-#include "H5Fpkg.h"             /* Files                                    */
-#include "H5Gpkg.h"             /* Groups                                   */
 #include "H5Iprivate.h"         /* IDs                                      */
-#include "H5Lpkg.h"             /* Links                                    */
-#include "H5MFprivate.h"        /* File memory management                   */
-#include "H5MMprivate.h"        /* Memory management                        */
-#include "H5Opkg.h"             /* Object headers                           */
 #include "H5Pprivate.h"         /* Property lists                           */
-#include "H5Rpkg.h"             /* References                               */
-#include "H5SMprivate.h"        /* Shared Object Header Messages            */
-#include "H5Tpkg.h"             /* Datatypes                                */
 #include "H5VLprivate.h"        /* Virtual Object Layer                     */
-#include "H5VLnative.h"         /* Native VOL connector                     */
 
-/*
- * The VOL connector identification number.
- */
-static hid_t H5VL_NATIVE_ID_g = H5I_INVALID_HID;
+#include "H5VLnative_private.h" /* Native VOL connector                     */
 
 
+/* The VOL connector identification number */
+static hid_t H5VL_NATIVE_ID_g = H5I_INVALID_HID;
+
 /* Prototypes */
 static herr_t H5VL__native_term(void);
 
-/* Atrribute callbacks */
-static void *H5VL__native_attr_create(void *obj, const H5VL_loc_params_t *loc_params, const char *attr_name, hid_t acpl_id, hid_t aapl_id, hid_t dxpl_id, void **req);
-static void *H5VL__native_attr_open(void *obj, const H5VL_loc_params_t *loc_params, const char *attr_name, hid_t aapl_id, hid_t dxpl_id, void **req);
-static herr_t H5VL__native_attr_read(void *attr, hid_t dtype_id, void *buf, hid_t dxpl_id, void **req);
-static herr_t H5VL__native_attr_write(void *attr, hid_t dtype_id, const void *buf, hid_t dxpl_id, void **req);
-static herr_t H5VL__native_attr_get(void *obj, H5VL_attr_get_t get_type, hid_t dxpl_id, void **req, va_list arguments);
-static herr_t H5VL__native_attr_specific(void *obj, const H5VL_loc_params_t *loc_params, H5VL_attr_specific_t specific_type, hid_t dxpl_id, void **req, va_list arguments);
-static herr_t H5VL__native_attr_optional(void *obj, hid_t dxpl_id, void **req, va_list arguments);
-static herr_t H5VL__native_attr_close(void *attr, hid_t dxpl_id, void **req);
-
-/* Dataset callbacks */
-static void *H5VL__native_dataset_create(void *obj, const H5VL_loc_params_t *loc_params, const char *name, hid_t dcpl_id, hid_t dapl_id, hid_t dxpl_id, void **req);
-static void *H5VL__native_dataset_open(void *obj, const H5VL_loc_params_t *loc_params, const char *name, hid_t dapl_id, hid_t dxpl_id, void **req);
-static herr_t H5VL__native_dataset_read(void *dset, hid_t mem_type_id, hid_t mem_space_id,
-                                       hid_t file_space_id, hid_t plist_id, void *buf, void **req);
-static herr_t H5VL__native_dataset_write(void *dset, hid_t mem_type_id, hid_t mem_space_id,
-                                        hid_t file_space_id, hid_t plist_id, const void *buf, void **req);
-static herr_t H5VL__native_dataset_get(void *dset, H5VL_dataset_get_t get_type, hid_t dxpl_id, void **req, va_list arguments);
-static herr_t H5VL__native_dataset_specific(void *dset, H5VL_dataset_specific_t specific_type, hid_t dxpl_id, void **req, va_list arguments);
-static herr_t H5VL__native_dataset_optional(void *dset, hid_t dxpl_id, void **req, va_list arguments);
-static herr_t H5VL__native_dataset_close(void *dset, hid_t dxpl_id, void **req);
-
-/* File callbacks */
-static void *H5VL__native_file_create(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id, hid_t dxpl_id, void **req);
-static void *H5VL__native_file_open(const char *name, unsigned flags, hid_t fapl_id, hid_t dxpl_id, void **req);
-static herr_t H5VL__native_file_get(void *file, H5VL_file_get_t get_type, hid_t dxpl_id, void **req, va_list arguments);
-static herr_t H5VL__native_file_specific(void *file, H5VL_file_specific_t specific_type, hid_t dxpl_id, void **req, va_list arguments);
-static herr_t H5VL__native_file_optional(void *file, hid_t dxpl_id, void **req, va_list arguments);
-static herr_t H5VL__native_file_close(void *file, hid_t dxpl_id, void **req);
-
-/* Group callbacks */
-static void *H5VL__native_group_create(void *obj, const H5VL_loc_params_t *loc_params, const char *name, hid_t gcpl_id, hid_t gapl_id, hid_t dxpl_id, void **req);
-static void *H5VL__native_group_open(void *obj, const H5VL_loc_params_t *loc_params, const char *name, hid_t gapl_id, hid_t dxpl_id, void **req);
-static herr_t H5VL__native_group_get(void *obj, H5VL_group_get_t get_type, hid_t dxpl_id, void **req, va_list arguments);
-static herr_t H5VL__native_group_specific(void *obj, H5VL_group_specific_t specific_type, hid_t dxpl_id, void **req, va_list arguments);
-static herr_t H5VL__native_group_optional(void *obj, hid_t dxpl_id, void **req, va_list arguments);
-static herr_t H5VL__native_group_close(void *grp, hid_t dxpl_id, void **req);
-
-/* Link callbacks */
-static herr_t H5VL__native_link_create(H5VL_link_create_type_t create_type, void *obj, 
-                                      const H5VL_loc_params_t *loc_params, hid_t lcpl_id, hid_t lapl_id, hid_t dxpl_id, void **req);
-static herr_t H5VL__native_link_copy(void *src_obj, const H5VL_loc_params_t *loc_params1,
-                                    void *dst_obj, const H5VL_loc_params_t *loc_params2,
-                                    hid_t lcpl_id, hid_t lapl_id, hid_t dxpl_id, void **req);
-static herr_t H5VL__native_link_move(void *src_obj, const H5VL_loc_params_t *loc_params1,
-                                    void *dst_obj, const H5VL_loc_params_t *loc_params2,
-                                    hid_t lcpl_id, hid_t lapl_id, hid_t dxpl_id, void **req);
-static herr_t H5VL__native_link_get(void *obj, const H5VL_loc_params_t *loc_params, H5VL_link_get_t get_type, hid_t dxpl_id, void **req, va_list arguments);
-static herr_t H5VL__native_link_specific(void *obj, const H5VL_loc_params_t *loc_params, H5VL_link_specific_t specific_type, hid_t dxpl_id, void **req, va_list arguments);
-
-/* Object callbacks */
-static void *H5VL__native_object_open(void *obj, const H5VL_loc_params_t *loc_params, H5I_type_t *opened_type, hid_t dxpl_id, void **req);
-static herr_t H5VL__native_object_copy(void *src_obj, const H5VL_loc_params_t *loc_params1, const char *src_name, 
-                                      void *dst_obj, const H5VL_loc_params_t *loc_params2, const char *dst_name, 
-                                      hid_t ocpypl_id, hid_t lcpl_id, hid_t dxpl_id, void **req);
-static herr_t H5VL__native_object_get(void *obj, const H5VL_loc_params_t *loc_params, H5VL_object_get_t get_type, hid_t dxpl_id, void **req, va_list arguments);
-static herr_t H5VL__native_object_specific(void *obj, const H5VL_loc_params_t *loc_params, H5VL_object_specific_t specific_type, hid_t dxpl_id, void **req, va_list arguments);
-static herr_t H5VL__native_object_optional(void *obj, hid_t dxpl_id, void **req, va_list arguments);
-
-/* Datatype callbacks */
-static void *H5VL__native_datatype_commit(void *obj, const H5VL_loc_params_t *loc_params, const char *name, hid_t type_id, hid_t lcpl_id, hid_t tcpl_id, hid_t tapl_id, hid_t dxpl_id, void **req);
-static void *H5VL__native_datatype_open(void *obj, const H5VL_loc_params_t *loc_params, const char *name, hid_t tapl_id, hid_t dxpl_id, void **req);
-static herr_t H5VL__native_datatype_get(void *dt, H5VL_datatype_get_t get_type, hid_t dxpl_id, void **req, va_list arguments);
-static herr_t H5VL__native_datatype_specific(void *dt, H5VL_datatype_specific_t specific_type, hid_t dxpl_id, void **req, va_list arguments);
-static herr_t H5VL__native_datatype_close(void *dt, hid_t dxpl_id, void **req);
-
 /* Native VOL connector class struct */
 static H5VL_class_t H5VL_native_cls_g = {
     H5VL_NATIVE_VERSION,                            /* version      */
@@ -210,7 +122,7 @@ static H5VL_class_t H5VL_native_cls_g = {
 /*-------------------------------------------------------------------------
  * Function:    H5VL_native_register
  *
- * Purpose:	Register the native VOL connector and retrieve an ID for it.
+ * Purpose:     Register the native VOL connector and retrieve an ID for it.
  *
  * Return:      Success:    The ID for the native connector
  *              Failure:    H5I_INVALID_HID
@@ -257,3398 +169,3 @@ H5VL__native_term(void)
     FUNC_LEAVE_NOAPI(SUCCEED)
 } /* end H5VL__native_term() */
 
-
-/*-------------------------------------------------------------------------
- * Function:	H5VL__native_attr_create
- *
- * Purpose:	Creates an attribute on an object.
- *
- * Return:	Success:	Pointer to attribute object
- *		Failure:	NULL
- *
- *-------------------------------------------------------------------------
- */
-static void *
-H5VL__native_attr_create(void *obj, const H5VL_loc_params_t *loc_params, const char *attr_name,
-    hid_t acpl_id, hid_t H5_ATTR_UNUSED aapl_id, hid_t H5_ATTR_UNUSED dxpl_id,
-    void H5_ATTR_UNUSED **req)
-{
-    H5G_loc_t       loc;                /* Object location */
-    H5G_loc_t       obj_loc;            /* Location used to open group */
-    hbool_t         loc_found = FALSE;  
-    H5P_genplist_t  *plist;             /* Property list pointer */
-    hid_t           type_id, space_id;
-    H5T_t	    *type, *dt;         /* Datatype to use for attribute */
-    H5S_t	    *space;             /* Dataspace to use for attribute */
-    H5A_t           *attr = NULL;
-    void            *ret_value = NULL;
-
-    FUNC_ENTER_STATIC
-
-    /* Get the plist structure */
-    if(NULL == (plist = (H5P_genplist_t *)H5I_object(acpl_id)))
-        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, NULL, "can't find object for ID")
-
-    /* get creation properties */
-    if(H5P_get(plist, H5VL_PROP_ATTR_TYPE_ID, &type_id) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get property value for datatype id")
-    if(H5P_get(plist, H5VL_PROP_ATTR_SPACE_ID, &space_id) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get property value for space id")
-
-    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file or file object")
-    if(0 == (H5F_INTENT(loc.oloc->file) & H5F_ACC_RDWR))
-        HGOTO_ERROR(H5E_ARGS, H5E_WRITEERROR, NULL, "no write intent on file")
-
-    if(NULL == (dt = (H5T_t *)H5I_object_verify(type_id, H5I_DATATYPE)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a datatype")
-    /* If this is a named datatype, get the connector's pointer to the datatype */
-    type = H5T_get_actual_type(dt);
-
-    if(NULL == (space = (H5S_t *)H5I_object_verify(space_id, H5I_DATASPACE)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a data space")
-
-    if(loc_params->type == H5VL_OBJECT_BY_SELF) {
-        /* H5Acreate */
-        /* Go do the real work for attaching the attribute to the dataset */
-        if(NULL == (attr = H5A__create(&loc, attr_name, type, space, acpl_id)))
-            HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, NULL, "unable to create attribute")
-    } /* end if */
-    else if(loc_params->type == H5VL_OBJECT_BY_NAME) {
-        /* H5Acreate_by_name */
-        if(NULL == (attr = H5A__create_by_name(&loc, loc_params->loc_data.loc_by_name.name, attr_name, type, space, acpl_id)))
-            HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, NULL, "unable to create attribute")
-    } /* end else-if */
-    else
-        HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, NULL, "unknown attribute create parameters")
-
-    ret_value = (void *)attr;
-
-done:
-    /* Release resources */
-    if(loc_found && H5G_loc_free(&obj_loc) < 0)
-        HDONE_ERROR(H5E_ATTR, H5E_CANTRELEASE, NULL, "can't free location") 
-
-   FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_attr_create() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5VL__native_attr_open
- *
- * Purpose:	Opens an attr inside a native H5 file.
- *
- * Return:	Success:	Pointer to attribute object
- *		Failure:	NULL
- *
- * Programmer:  Mohamad Chaarawi
- *              March, 2012
- *
- *-------------------------------------------------------------------------
- */
-static void *
-H5VL__native_attr_open(void *obj, const H5VL_loc_params_t *loc_params, const char *attr_name, 
-    hid_t H5_ATTR_UNUSED aapl_id, hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
-{
-    H5G_loc_t    loc;             /* Object location */
-    H5A_t        *attr = NULL;    /* Attribute opened */
-    void         *ret_value;
-
-    FUNC_ENTER_STATIC
-
-    /* check arguments */
-    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file or file object")
-
-    if(loc_params->type == H5VL_OBJECT_BY_SELF) {
-        /* H5Aopen */
-        /* Open the attribute */
-        if(NULL == (attr = H5A__open(&loc, attr_name)))
-            HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, NULL, "unable to open attribute: '%s'", attr_name)
-    } /* end if */
-    else if(loc_params->type == H5VL_OBJECT_BY_NAME) {
-        /* H5Aopen_by_name */
-        /* Open the attribute on the object header */
-        if(NULL == (attr = H5A__open_by_name(&loc, loc_params->loc_data.loc_by_name.name, attr_name)))
-            HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, NULL, "can't open attribute")
-    } /* end else-if */
-    else if(loc_params->type == H5VL_OBJECT_BY_IDX) {
-        /* H5Aopen_by_idx */
-        /* Open the attribute in the object header */
-        if(NULL == (attr = H5A__open_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, 
-                                           loc_params->loc_data.loc_by_idx.idx_type, 
-                                           loc_params->loc_data.loc_by_idx.order, 
-                                           loc_params->loc_data.loc_by_idx.n)))
-            HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, NULL, "unable to open attribute")
-    } /* end else-if */
-    else
-        HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, NULL, "unknown attribute open parameters")
-
-    ret_value = (void *)attr;
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_attr_open() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5VL__native_attr_read
- *
- * Purpose:	Reads data from attribute.
- *
- * Return:	Non-negative on success/Negative on failure
- *
- * Programmer:  Mohamad Chaarawi
- *              March, 2012
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_attr_read(void *attr, hid_t dtype_id, void *buf,
-    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
-{
-    H5T_t *mem_type;            /* Memory datatype */
-    herr_t ret_value;           /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    if(NULL == (mem_type = (H5T_t *)H5I_object_verify(dtype_id, H5I_DATATYPE)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a datatype")
-
-    /* Go write the actual data to the attribute */
-    if((ret_value = H5A__read((H5A_t*)attr, mem_type, buf)) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_READERROR, FAIL, "unable to read attribute")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_attr_read() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5VL__native_attr_write
- *
- * Purpose:	Writes data to attribute.
- *
- * Return:	Non-negative on success/Negative on failure
- *
- * Programmer:  Mohamad Chaarawi
- *              March, 2012
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_attr_write(void *attr, hid_t dtype_id, const void *buf,
-    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
-{
-    H5T_t *mem_type;            /* Memory datatype */
-    herr_t ret_value;           /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    if(NULL == (mem_type = (H5T_t *)H5I_object_verify(dtype_id, H5I_DATATYPE)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a datatype")
-
-    /* Go write the actual data to the attribute */
-    if((ret_value = H5A__write((H5A_t*)attr, mem_type, buf)) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_WRITEERROR, FAIL, "unable to write attribute")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_attr_write() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5VL__native_attr_get
- *
- * Purpose:	Gets information about an attribute
- *
- * Return:	Success:	0
- *		Failure:	-1
- *
- * Programmer:  Mohamad Chaarawi
- *              March, 2012
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_attr_get(void *obj, H5VL_attr_get_t get_type,
-    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
-{
-    herr_t      ret_value = SUCCEED;    /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    switch(get_type) {
-        /* H5Aget_space */
-        case H5VL_ATTR_GET_SPACE:
-            {
-                hid_t	*ret_id = HDva_arg(arguments, hid_t *);
-                H5A_t   *attr = (H5A_t *)obj;
-
-                if((*ret_id = H5A_get_space(attr)) < 0)
-                    HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get space ID of attribute")
-                break;
-            }
-
-        /* H5Aget_type */
-        case H5VL_ATTR_GET_TYPE:
-            {
-                hid_t	*ret_id = HDva_arg(arguments, hid_t *);
-                H5A_t   *attr = (H5A_t *)obj;
-
-                if((*ret_id = H5A__get_type(attr)) < 0)
-                    HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get datatype ID of attribute")
-                break;
-            }
-
-        /* H5Aget_create_plist */
-        case H5VL_ATTR_GET_ACPL:
-            {
-                hid_t	*ret_id = HDva_arg(arguments, hid_t *);
-                H5A_t   *attr = (H5A_t *)obj;
-
-                if((*ret_id = H5A__get_create_plist(attr)) < 0)
-                    HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get creation property list for attr")
-
-                break;
-            }
-
-        /* H5Aget_name */
-        case H5VL_ATTR_GET_NAME:
-            {
-                const H5VL_loc_params_t *loc_params = HDva_arg(arguments, const H5VL_loc_params_t *);
-                size_t	buf_size = HDva_arg(arguments, size_t);
-                char    *buf = HDva_arg(arguments, char *);
-                ssize_t	*ret_val = HDva_arg(arguments, ssize_t *);
-                H5A_t   *attr = NULL;
-
-                if(H5VL_OBJECT_BY_SELF == loc_params->type) {
-                    attr = (H5A_t *)obj;
-                    /* Call private function in turn */
-                    if(0 > (*ret_val = H5A__get_name(attr, buf_size, buf)))
-                        HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "can't get attribute name")
-                }
-                else if(H5VL_OBJECT_BY_IDX == loc_params->type) {
-                    H5G_loc_t loc;
-                    
-                    /* check arguments */
-                    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
-                        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-                    /* Open the attribute on the object header */
-                    if(NULL == (attr = H5A__open_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, 
-                                                       loc_params->loc_data.loc_by_idx.idx_type, 
-                                                       loc_params->loc_data.loc_by_idx.order, 
-                                                       loc_params->loc_data.loc_by_idx.n)))
-                        HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "can't open attribute")
-
-                    /* Get the length of the name */
-                    *ret_val = (ssize_t)HDstrlen(attr->shared->name);
-
-                    /* Copy the name into the user's buffer, if given */
-                    if(buf) {
-                        HDstrncpy(buf, attr->shared->name, MIN((size_t)(*ret_val + 1), buf_size));
-                        if((size_t)(*ret_val) >= buf_size)
-                            buf[buf_size - 1]='\0';
-                    } /* end if */
-
-                    /* Release resources */
-                    if(attr && H5A__close(attr) < 0)
-                        HGOTO_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
-                }
-                else
-                    HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't get name of attr")
-
-                break;
-            }
-
-        /* H5Aget_info */
-        case H5VL_ATTR_GET_INFO:
-            {
-                const H5VL_loc_params_t *loc_params = HDva_arg(arguments, const H5VL_loc_params_t *);
-                H5A_info_t   *ainfo = HDva_arg(arguments, H5A_info_t *);
-                H5A_t   *attr = NULL;
-
-                if(H5VL_OBJECT_BY_SELF == loc_params->type) {
-                    attr = (H5A_t *)obj;
-                    if(H5A__get_info(attr, ainfo) < 0)
-                        HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get attribute info")
-                }
-                else if(H5VL_OBJECT_BY_NAME == loc_params->type) {
-                    char *attr_name = HDva_arg(arguments, char *);
-                    H5G_loc_t loc;
-                    
-                    /* check arguments */
-                    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
-                        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-                    /* Open the attribute on the object header */
-                    if(NULL == (attr = H5A__open_by_name(&loc, loc_params->loc_data.loc_by_name.name, attr_name)))
-                        HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "can't open attribute")
-
-                    /* Get the attribute information */
-                    if(H5A__get_info(attr, ainfo) < 0)
-                        HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "unable to get attribute info")
-
-                    /* Release resources */
-                    if(attr && H5A__close(attr) < 0)
-                        HGOTO_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
-                }
-                else if(H5VL_OBJECT_BY_IDX == loc_params->type) {
-                    H5G_loc_t loc;
-                    
-                    /* check arguments */
-                    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
-                        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-                    /* Open the attribute on the object header */
-                    if(NULL == (attr = H5A__open_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, 
-                                                       loc_params->loc_data.loc_by_idx.idx_type, 
-                                                       loc_params->loc_data.loc_by_idx.order, 
-                                                       loc_params->loc_data.loc_by_idx.n)))
-                        HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "can't open attribute")
-
-                    /* Get the attribute information */
-                    if(H5A__get_info(attr, ainfo) < 0)
-                        HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "unable to get attribute info")
-
-                    /* Release resources */
-                    if(attr && H5A__close(attr) < 0)
-                        HGOTO_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
-                }
-                else
-                    HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't get name of attr")
-
-                break;
-            }
-
-        case H5VL_ATTR_GET_STORAGE_SIZE:
-            {
-                hsize_t *ret = HDva_arg(arguments, hsize_t *);
-                H5A_t   *attr = (H5A_t *)obj;
-
-                /* Set return value */
-                *ret = attr->shared->data_size;
-                break;
-            }
-
-        default:
-            HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't get this type of information from attr")
-    } /* end switch */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_attr_get() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5VL__native_attr_specific
- *
- * Purpose:	Specific operation on attribute
- *
- * Return:	Success:	0
- *		Failure:	-1
- *
- * Programmer:  Mohamad Chaarawi
- *              August, 2014
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_attr_specific(void *obj, const H5VL_loc_params_t *loc_params, H5VL_attr_specific_t specific_type, 
-    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
-{
-    H5G_loc_t   loc;
-    herr_t      ret_value = SUCCEED;    /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    /* Get location for passed-in object */
-    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-    switch(specific_type) {
-        case H5VL_ATTR_DELETE:
-            {
-                char    *attr_name = HDva_arg(arguments, char *);
-
-                if(H5VL_OBJECT_BY_SELF == loc_params->type) {
-                    /* H5Adelete */
-                    /* Delete the attribute from the location */
-                    if(H5O__attr_remove(loc.oloc, attr_name) < 0)
-                        HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute")
-                } /* end if */
-                else if(H5VL_OBJECT_BY_NAME == loc_params->type) {
-                    /* H5Adelete_by_name */
-                    /* Delete the attribute */
-                    if(H5A__delete_by_name(&loc, loc_params->loc_data.loc_by_name.name, attr_name) < 0)
-                        HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute")
-                } /* end else-if */
-                else if(H5VL_OBJECT_BY_IDX == loc_params->type) {
-                    /* H5Adelete_by_idx */
-                    /* Delete the attribute from the location */
-                    if(H5A__delete_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, loc_params->loc_data.loc_by_idx.idx_type,
-                            loc_params->loc_data.loc_by_idx.order, loc_params->loc_data.loc_by_idx.n) < 0)
-                        HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute")
-                } /* end else-if */
-                else
-                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown attribute remove parameters")
-                break;
-            }
-
-        case H5VL_ATTR_EXISTS:
-            {
-                const char *attr_name = HDva_arg(arguments, const char *);
-                htri_t	*ret = HDva_arg(arguments, htri_t *);
-
-                if(loc_params->type == H5VL_OBJECT_BY_SELF) { /* H5Aexists */
-                    /* Check if the attribute exists */
-                    if((*ret = H5O__attr_exists(loc.oloc, attr_name)) < 0)
-                        HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "unable to determine if attribute exists")
-                } /* end if */
-                else if(loc_params->type == H5VL_OBJECT_BY_NAME) { /* H5Aexists_by_name */
-                    /* Check if the attribute exists */
-                    if((*ret = H5A__exists_by_name(loc, loc_params->loc_data.loc_by_name.name, attr_name)) < 0)
-                        HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "unable to determine if attribute exists")
-                } /* end else-if */
-                else
-                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown parameters")
-                break;
-            }
-
-        case H5VL_ATTR_ITER:
-            {
-                H5_index_t          idx_type    = HDva_arg(arguments, H5_index_t);
-                H5_iter_order_t     order       = HDva_arg(arguments, H5_iter_order_t);
-                hsize_t            *idx         = HDva_arg(arguments, hsize_t *);
-                H5A_operator2_t     op          = HDva_arg(arguments, H5A_operator2_t);
-                void               *op_data     = HDva_arg(arguments, void *);
-
-                if(loc_params->type == H5VL_OBJECT_BY_SELF) { /* H5Aiterate2 */
-                    /* Iterate over attributes */
-                    if((ret_value = H5A__iterate(&loc, ".", idx_type, order, idx, op, op_data)) < 0)
-                        HGOTO_ERROR(H5E_ATTR, H5E_BADITER, FAIL, "error iterating over attributes")
-                } /* end if */
-                else if(loc_params->type == H5VL_OBJECT_BY_NAME) { /* H5Aiterate_by_name */
-                    /* Iterate over attributes by name */
-                    if((ret_value = H5A__iterate(&loc, loc_params->loc_data.loc_by_name.name, idx_type, order, idx, op, op_data)) < 0)
-                        HGOTO_ERROR(H5E_ATTR, H5E_BADITER, FAIL, "attribute iteration failed");
-                } /* end else-if */
-                else
-                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown parameters")
-                break;
-            }
-
-        /* H5Arename/rename_by_name */
-        case H5VL_ATTR_RENAME:
-            {
-                const char *old_name  = HDva_arg(arguments, const char *);
-                const char *new_name  = HDva_arg(arguments, const char *);
-
-                if(loc_params->type == H5VL_OBJECT_BY_SELF) { /* H5Arename */
-                    /* Call attribute rename routine */
-                    if(H5O__attr_rename(loc.oloc, old_name, new_name) < 0)
-                        HGOTO_ERROR(H5E_ATTR, H5E_CANTRENAME, FAIL, "can't rename attribute")
-                } /* end if */
-                else if(loc_params->type == H5VL_OBJECT_BY_NAME) { /* H5Arename_by_name */
-                    /* Call attribute rename routine */
-                    if(H5A__rename_by_name(loc, loc_params->loc_data.loc_by_name.name, old_name, new_name) < 0)
-                        HGOTO_ERROR(H5E_ATTR, H5E_CANTRENAME, FAIL, "can't rename attribute")
-                } /* end else-if */
-                else
-                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown attribute rename parameters")
-                break;
-            }
-
-        default:
-            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "invalid specific operation")
-    } /* end switch */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_attr_specific() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_attr_optional
- *
- * Purpose:     Perform a connector-specific operation on a native attribute
- *
- * Return:      SUCCEED/FAIL
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_attr_optional(void H5_ATTR_UNUSED *obj, hid_t H5_ATTR_UNUSED dxpl_id,
-    void H5_ATTR_UNUSED **req, va_list arguments)
-{
-    H5VL_native_attr_optional_t optional_type;
-    herr_t ret_value = SUCCEED;    /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    optional_type = HDva_arg(arguments, H5VL_native_attr_optional_t);
-    switch(optional_type) {
-#ifndef H5_NO_DEPRECATED_SYMBOLS
-        case H5VL_NATIVE_ATTR_ITERATE_OLD:
-            {
-                hid_t loc_id = HDva_arg(arguments, hid_t);
-                unsigned *attr_num = HDva_arg(arguments, unsigned *);
-                H5A_operator1_t op = HDva_arg(arguments, H5A_operator1_t);
-                void *op_data = HDva_arg(arguments, void *);
-
-                /* Call the actual iteration routine */
-                if((ret_value = H5A__iterate_old(loc_id, attr_num, op, op_data)) < 0)
-                    HERROR(H5E_VOL, H5E_BADITER, "error iterating over attributes");
-
-                break;
-            }
-#else
-        /* XXX: This case only exists because this is the only attribute optional
-         *      value and we can't have empty enums. Delete it when we have another
-         *      attribute optional enum value.
-         */
-        case H5VL_NATIVE_ATTR_ITERATE_OLD:
-            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "H5VL_NATIVE_ATTR_ITERATE_OLD is not a valid value when the library is built without deprecated routines")
-#endif /* H5_NO_DEPRECATED_SYMBOLS */
-
-        default:
-            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "invalid optional operation")
-    } /* end switch */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_attr_optional() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5VL__native_attr_close
- *
- * Purpose:	Closes an attribute.
- *
- * Return:	Success:	0
- *		Failure:	-1, attr not closed.
- *
- * Programmer:  Mohamad Chaarawi
- *              March, 2012
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_attr_close(void *attr, hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
-{
-    herr_t ret_value = SUCCEED;                 /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    if(H5A__close((H5A_t*)attr) < 0)
-        HGOTO_ERROR(H5E_SYM, H5E_CANTDEC, FAIL, "can't close attribute")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_attr_close() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_dataset_create
- *
- * Purpose:     Creates a dataset in a native HDF5 file
- *
- * Return:      Success:    Pointer to a dataset struct
- *              Failure:    NULL
- *
- *-------------------------------------------------------------------------
- */
-static void *
-H5VL__native_dataset_create(void *obj, const H5VL_loc_params_t *loc_params,
-    const char *name, hid_t dcpl_id, hid_t dapl_id, hid_t H5_ATTR_UNUSED dxpl_id,
-    void H5_ATTR_UNUSED **req)
-{
-    H5P_genplist_t *plist;              /* Property list pointer */
-    H5G_loc_t	    loc;                 /* Object location to insert dataset into */
-    hid_t           type_id = H5I_INVALID_HID;
-    hid_t           space_id = H5I_INVALID_HID;
-    hid_t           lcpl_id = H5I_INVALID_HID;
-    H5D_t          *dset = NULL;        /* New dataset's info */
-    const H5S_t    *space;              /* Dataspace for dataset */
-    void           *ret_value;
-
-    FUNC_ENTER_STATIC
-
-    /* Get the plist structure */
-    if(NULL == (plist = (H5P_genplist_t *)H5I_object(dcpl_id)))
-        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, NULL, "can't find object for ID")
-
-    /* Get creation properties */
-    if(H5P_get(plist, H5VL_PROP_DSET_TYPE_ID, &type_id) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get property value for datatype id")
-    if(H5P_get(plist, H5VL_PROP_DSET_SPACE_ID, &space_id) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get property value for space id")
-    if(H5P_get(plist, H5VL_PROP_DSET_LCPL_ID, &lcpl_id) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get property value for lcpl id")
-
-    /* Check arguments */
-    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file or file object")
-    if(H5I_DATATYPE != H5I_get_type(type_id))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a datatype ID")
-    if(NULL == (space = (const H5S_t *)H5I_object_verify(space_id, H5I_DATASPACE)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a dataspace ID")
-
-    /* H5Dcreate_anon */
-    if(NULL == name) {
-        /* build and open the new dataset */
-        if(NULL == (dset = H5D__create(loc.oloc->file, type_id, space, dcpl_id, dapl_id)))
-            HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "unable to create dataset")
-    } /* end if */
-    /* H5Dcreate2 */
-    else {
-        /* Create the new dataset & get its ID */
-        if(NULL == (dset = H5D__create_named(&loc, name, type_id, space, lcpl_id, dcpl_id, dapl_id)))
-            HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "unable to create dataset")
-    } /* end else */
-
-    ret_value = (void *)dset;
-
-done:
-    if(NULL == name) {
-        /* Release the dataset's object header, if it was created */
-        if(dset) {
-            H5O_loc_t *oloc;         /* Object location for dataset */
-
-            /* Get the new dataset's object location */
-            if(NULL == (oloc = H5D_oloc(dset)))
-                HDONE_ERROR(H5E_DATASET, H5E_CANTGET, NULL, "unable to get object location of dataset")
-
-            /* Decrement refcount on dataset's object header in memory */
-            if(H5O_dec_rc_by_loc(oloc) < 0)
-                HDONE_ERROR(H5E_DATASET, H5E_CANTDEC, NULL, "unable to decrement refcount on newly created object")
-        } /* end if */
-    } /* end if */
-
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_dataset_create() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_dataset_open
- *
- * Purpose:     Opens a dataset in a native HDF5 file.
- *
- * Return:      Success:    Pointer to a dataset struct
- *              Failure:    NULL
- *
- *-------------------------------------------------------------------------
- */
-static void *
-H5VL__native_dataset_open(void *obj, const H5VL_loc_params_t *loc_params, const char *name, 
-    hid_t dapl_id, hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
-{
-    H5D_t       *dset = NULL;
-    H5G_loc_t	 loc;		        /* Object location of group */
-    void         *ret_value = NULL;
-
-    FUNC_ENTER_STATIC
-
-    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file or file object")
-
-    /* Open the dataset */
-    if(NULL == (dset = H5D__open_name(&loc, name, dapl_id)))
-        HGOTO_ERROR(H5E_DATASET, H5E_CANTOPENOBJ, NULL, "unable to open dataset")
-
-    ret_value = (void *)dset;
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_dataset_open() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_dataset_read
- *
- * Purpose:     Reads raw data from a dataset into a buffer.
- *
- * Return:      SUCCEED/FAIL
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_dataset_read(void *obj, hid_t mem_type_id, hid_t mem_space_id,
-    hid_t file_space_id, hid_t H5_ATTR_UNUSED dxpl_id, void *buf,
-    void H5_ATTR_UNUSED **req)
-{
-    H5D_t         *dset = (H5D_t *)obj;
-    const H5S_t   *mem_space = NULL;
-    const H5S_t   *file_space = NULL;
-    herr_t         ret_value = SUCCEED;                 /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    /* Check arguments */
-    if(NULL == dset->oloc.file)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "dataset is not associated with a file")
-
-    /* Get validated dataspace pointers */
-    if(H5S_get_validated_dataspace(mem_space_id, &mem_space) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "could not get a validated dataspace from mem_space_id")
-    if(H5S_get_validated_dataspace(file_space_id, &file_space) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "could not get a validated dataspace from file_space_id")
-
-    /* Read raw data */
-    if(H5D__read(dset, mem_type_id, mem_space, file_space, buf/*out*/) < 0)
-        HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL, "can't read data")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_dataset_read() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_dataset_write
- *
- * Purpose:     Writes raw data from a buffer into a dataset.
- *
- * Return:      SUCCEED/FAIL
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_dataset_write(void *obj, hid_t mem_type_id, hid_t mem_space_id,
-    hid_t file_space_id, hid_t H5_ATTR_UNUSED dxpl_id, const void *buf,
-    void H5_ATTR_UNUSED **req)
-{
-    H5D_t           *dset = (H5D_t *)obj;
-    const H5S_t     *mem_space = NULL;
-    const H5S_t     *file_space = NULL;
-    herr_t           ret_value = SUCCEED;        /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    /* check arguments */
-    if(NULL == dset->oloc.file)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "dataset is not associated with a file")
-
-    /* Get validated dataspace pointers */
-    if(H5S_get_validated_dataspace(mem_space_id, &mem_space) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "could not get a validated dataspace from mem_space_id")
-    if(H5S_get_validated_dataspace(file_space_id, &file_space) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "could not get a validated dataspace from file_space_id")
-
-    /* Write the data */
-    if(H5D__write(dset, mem_type_id, mem_space, file_space, buf) < 0) 
-        HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "can't write data")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_dataset_write() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_dataset_get
- *
- * Purpose:     Gets certain information about a dataset
- *
- * Return:      SUCCEED/FAIL
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_dataset_get(void *obj, H5VL_dataset_get_t get_type,
-    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
-{
-    H5D_t       *dset = (H5D_t *)obj;
-    herr_t       ret_value = SUCCEED;    /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    switch(get_type) {
-        /* H5Dget_space */
-        case H5VL_DATASET_GET_SPACE:
-            {
-                hid_t	*ret_id = HDva_arg(arguments, hid_t *);
-
-                if((*ret_id = H5D__get_space(dset)) < 0)
-                    HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get space ID of dataset")
-
-                break;
-            }
-
-        /* H5Dget_space_statuc */
-        case H5VL_DATASET_GET_SPACE_STATUS:
-            {
-                H5D_space_status_t *allocation = HDva_arg(arguments, H5D_space_status_t *);
-
-                /* Read data space address and return */
-                if(H5D__get_space_status(dset, allocation) < 0)
-                    HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to get space status")
-
-                break;
-            }
-
-        /* H5Dget_type */
-        case H5VL_DATASET_GET_TYPE:
-            {
-                hid_t	*ret_id = HDva_arg(arguments, hid_t *);
-
-                if((*ret_id = H5D__get_type(dset)) < 0)
-                    HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get datatype ID of dataset")
-
-                break;
-            }
-
-        /* H5Dget_create_plist */
-        case H5VL_DATASET_GET_DCPL:
-            {
-                hid_t	*ret_id = HDva_arg(arguments, hid_t *);
-
-                if((*ret_id = H5D_get_create_plist(dset)) < 0)
-                    HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get creation property list for dataset")
-
-                break;
-            }
-
-        /* H5Dget_access_plist */
-        case H5VL_DATASET_GET_DAPL:
-            {
-                hid_t	*ret_id = HDva_arg(arguments, hid_t *);
-
-                if((*ret_id = H5D_get_access_plist(dset)) < 0)
-                    HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get access property list for dataset")
-
-                break;
-            }
-
-        /* H5Dget_storage_size */
-        case H5VL_DATASET_GET_STORAGE_SIZE:
-            {
-                hsize_t *ret = HDva_arg(arguments, hsize_t *);
-
-                /* Set return value */
-                if(H5D__get_storage_size(dset, ret) < 0)
-                    HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't get size of dataset's storage")
-                break;
-            }
-
-        /* H5Dget_offset */
-        case H5VL_DATASET_GET_OFFSET:
-            {
-                haddr_t *ret = HDva_arg(arguments, haddr_t *);
-
-                /* Set return value */
-                *ret = H5D__get_offset(dset);
-                if(!H5F_addr_defined(*ret))
-                    *ret = HADDR_UNDEF;
-                break;
-            }
-
-        default:
-            HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't get this type of information from dataset")
-    } /* end switch */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_dataset_get() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_dataset_specific
- *
- * Purpose:     Specific operation on dataset
- *
- * Return:      SUCCEED/FAIL
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_dataset_specific(void *obj, H5VL_dataset_specific_t specific_type, 
-    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
-{
-    H5D_t       *dset = (H5D_t *)obj;
-    herr_t       ret_value = SUCCEED;    /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    switch(specific_type) {
-        /* H5Dspecific_space */
-        case H5VL_DATASET_SET_EXTENT:
-            {
-                const hsize_t *size = HDva_arg(arguments, const hsize_t *); 
-
-                if(H5D__set_extent(dset, size) < 0)
-                    HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to set extent of dataset")
-                break;
-            }
-
-        case H5VL_DATASET_FLUSH:
-            {
-                hid_t dset_id = HDva_arg(arguments, hid_t);
-
-                /* Flush the dataset */
-                if(H5D__flush(dset, dset_id) < 0)
-                    HGOTO_ERROR(H5E_DATASET, H5E_CANTFLUSH, FAIL, "unable to flush dataset")
-
-                break;
-            }
-
-        case H5VL_DATASET_REFRESH:
-            {
-                hid_t dset_id = HDva_arg(arguments, hid_t);
-
-                /* Refresh the dataset */
-                if((H5D__refresh(dset_id, dset)) < 0)
-                    HGOTO_ERROR(H5E_DATASET, H5E_CANTLOAD, FAIL, "unable to refresh dataset")
-
-                break;
-            }
-
-        default:
-            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "invalid specific operation")
-    } /* end switch */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_dataset_specific() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_dataset_optional
- *
- * Purpose:     Perform a connector-specific operation on a native dataset
- *
- * Return:      SUCCEED/FAIL
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_dataset_optional(void *obj, hid_t H5_ATTR_UNUSED dxpl_id,
-    void H5_ATTR_UNUSED **req, va_list arguments)
-{
-    H5D_t *dset = NULL;             /* Dataset */
-    H5VL_native_dataset_optional_t optional_type = HDva_arg(arguments, H5VL_native_dataset_optional_t);
-    herr_t ret_value = SUCCEED;    /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    switch(optional_type) {
-        case H5VL_NATIVE_DATASET_FORMAT_CONVERT:
-            {
-                dset = (H5D_t *)obj;
-
-                switch(dset->shared->layout.type) {
-                    case H5D_CHUNKED:
-                        /* Convert the chunk indexing type to version 1 B-tree if not */
-                        if(dset->shared->layout.u.chunk.idx_type != H5D_CHUNK_IDX_BTREE)
-                            if((H5D__format_convert(dset)) < 0)
-                                HGOTO_ERROR(H5E_DATASET, H5E_CANTLOAD, FAIL, "unable to downgrade chunk indexing type for dataset")
-                        break;
-
-                    case H5D_CONTIGUOUS:
-                    case H5D_COMPACT:
-                        /* Downgrade the layout version to 3 if greater than 3 */
-                        if(dset->shared->layout.version > H5O_LAYOUT_VERSION_DEFAULT)
-                            if((H5D__format_convert(dset)) < 0)
-                                HGOTO_ERROR(H5E_DATASET, H5E_CANTLOAD, FAIL, "unable to downgrade layout version for dataset")
-                        break;
-
-                    case H5D_VIRTUAL:
-                        /* Nothing to do even though layout is version 4 */
-                        break;
-
-                    case H5D_LAYOUT_ERROR:
-                    case H5D_NLAYOUTS:
-                        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid dataset layout type")
-
-                    default: 
-                        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "unknown dataset layout type")
-                } /* end switch */
-
-                break;
-            }
-
-        case H5VL_NATIVE_DATASET_GET_CHUNK_INDEX_TYPE:
-            {
-                H5D_chunk_index_t *idx_type = HDva_arg(arguments, H5D_chunk_index_t *);
-
-                dset = (H5D_t *)obj;
-
-                /* Make sure the dataset is chunked */
-                if(H5D_CHUNKED != dset->shared->layout.type)
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a chunked dataset")
-
-                /* Get the chunk indexing type */
-                *idx_type = dset->shared->layout.u.chunk.idx_type;
-
-                break;
-            }
-
-        case H5VL_NATIVE_DATASET_GET_CHUNK_STORAGE_SIZE:
-            {
-                hsize_t *offset = HDva_arg(arguments, hsize_t *);
-                hsize_t *chunk_nbytes = HDva_arg(arguments, hsize_t *);
-
-                dset = (H5D_t *)obj;
-
-                /* Make sure the dataset is chunked */
-                if(H5D_CHUNKED != dset->shared->layout.type)
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a chunked dataset")
-
-                /* Call private function */
-                if(H5D__get_chunk_storage_size(dset, offset, chunk_nbytes) < 0)
-                    HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't get storage size of chunk")
-
-                break;
-            }
-
-        case H5VL_NATIVE_DATASET_CHUNK_READ:
-            {
-                const       hsize_t *offset     = HDva_arg(arguments, hsize_t *);
-                uint32_t   *filters             = HDva_arg(arguments, uint32_t *);
-                void       *buf                 = HDva_arg(arguments, void *);
-                hsize_t     offset_copy[H5O_LAYOUT_NDIMS];  /* Internal copy of chunk offset */
-
-                dset = (H5D_t *)obj;
-
-                /* Check arguments */
-                if(NULL == dset->oloc.file)
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "dataset is not associated with a file")
-                if(H5D_CHUNKED != dset->shared->layout.type)
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a chunked dataset")
-
-                /* Copy the user's offset array so we can be sure it's terminated properly.
-                 * (we don't want to mess with the user's buffer).
-                 */
-                if(H5D__get_offset_copy(dset, offset, offset_copy) < 0)
-                    HGOTO_ERROR(H5E_DATASET, H5E_CANTALLOC, FAIL, "failure to copy offset array")
-
-                /* Read the raw chunk */
-                if(H5D__chunk_direct_read(dset, offset_copy, filters, buf) < 0)
-                    HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL, "can't read unprocessed chunk data")
-
-                break;
-            }
-
-        case H5VL_NATIVE_DATASET_CHUNK_WRITE:
-            {
-                uint32_t        filters             = HDva_arg(arguments, uint32_t);
-                const  hsize_t *offset              = HDva_arg(arguments, const hsize_t *);
-                uint32_t        data_size_32        = HDva_arg(arguments, uint32_t);
-                const void     *buf                 = HDva_arg(arguments, const void *);
-                hsize_t         offset_copy[H5O_LAYOUT_NDIMS];  /* Internal copy of chunk offset */
-
-                dset = (H5D_t *)obj;
-
-                /* Check arguments */
-                if(NULL == dset->oloc.file)
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "dataset is not associated with a file")
-                if(H5D_CHUNKED != dset->shared->layout.type)
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a chunked dataset")
-
-                /* Copy the user's offset array so we can be sure it's terminated properly.
-                 * (we don't want to mess with the user's buffer).
-                 */
-                if(H5D__get_offset_copy(dset, offset, offset_copy) < 0)
-                    HGOTO_ERROR(H5E_DATASET, H5E_CANTALLOC, FAIL, "failure to copy offset array")
-
-                /* Write chunk */
-                if(H5D__chunk_direct_write(dset, filters, offset_copy, data_size_32, buf) < 0)
-                    HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "can't write unprocessed chunk data")
-
-                break;
-            }
-
-        default:
-            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "invalid optional operation")
-    } /* end switch */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_dataset_optional() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_dataset_close
- *
- * Purpose:     Closes a dataset.
- *
- * Return:      Success:    SUCCEED
- *              Failure:    FAIL (dataset will not be closed)
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_dataset_close(void *dset, hid_t H5_ATTR_UNUSED dxpl_id,
-    void H5_ATTR_UNUSED **req)
-{
-    herr_t ret_value = SUCCEED;                 /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    if(H5D_close((H5D_t*)dset) < 0)
-        HGOTO_ERROR(H5E_DATASET, H5E_CANTDEC, FAIL, "can't close dataset")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_dataset_close() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_file_create
- *
- * Purpose:     Creates a file as a native HDF5 file.
- *
- * Return:      Success:    A pointer to an H5F_t file struct
- *
- *              Failure:    NULL
- *
- *-------------------------------------------------------------------------
- */
-static void *
-H5VL__native_file_create(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id, 
-    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
-{
-    H5F_t *new_file = NULL;
-    void  *ret_value = NULL;
-
-    FUNC_ENTER_STATIC
-
-    /* Adjust bit flags by turning on the creation bit and making sure that
-     * the EXCL or TRUNC bit is set.  All newly-created files are opened for
-     * reading and writing.
-     */
-    if(0 == (flags & (H5F_ACC_EXCL|H5F_ACC_TRUNC)))
-        flags |= H5F_ACC_EXCL;	 /*default*/
-    flags |= H5F_ACC_RDWR | H5F_ACC_CREAT;
-
-    /* Create the file */ 
-    if(NULL == (new_file = H5F_open(name, flags, fcpl_id, fapl_id)))
-        HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to create file")
-    new_file->id_exists = TRUE;
-
-    ret_value = (void *)new_file;
-
-done:
-    if(NULL == ret_value && new_file) 
-        if(H5F__close(new_file) < 0)
-            HDONE_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, NULL, "problems closing file")
-
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_file_create() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_file_open
- *
- * Purpose:     Opens a file as a native HDF5 file.
- *
- * Return:      Success:    A pointer to an H5F_t file struct
- *
- *              Failure:    NULL
- *
- *-------------------------------------------------------------------------
- */
-static void *
-H5VL__native_file_open(const char *name, unsigned flags, hid_t fapl_id,
-    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
-{
-    H5F_t *new_file = NULL;
-    void  *ret_value = NULL;
-
-    FUNC_ENTER_STATIC
-
-    /* Open the file */ 
-    if(NULL == (new_file = H5F_open(name, flags, H5P_FILE_CREATE_DEFAULT, fapl_id)))
-        HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to open file")
-    new_file->id_exists = TRUE;
-
-    ret_value = (void *)new_file;
-
-done:
-    if(NULL == ret_value && new_file && H5F_try_close(new_file, NULL) < 0)
-        HDONE_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, NULL, "problems closing file")
-
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_file_open() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_file_get
- *
- * Purpose:     Get info about a file
- *
- * Return:      SUCCEED/FAIL
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_file_get(void *obj, H5VL_file_get_t get_type,
-    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
-{
-    H5F_t       *f = NULL;              /* File struct */
-    herr_t      ret_value = SUCCEED;    /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    switch(get_type) {
-        /* H5Fget_access_plist */
-        case H5VL_FILE_GET_FAPL:
-            {
-                H5P_genplist_t *new_plist;              /* New property list */
-                hid_t          *plist_id = HDva_arg(arguments, hid_t *);
-
-                f = (H5F_t *)obj;
-
-                /* Retrieve the file's access property list */
-                if((*plist_id = H5F_get_access_plist(f, TRUE)) < 0)
-                    HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get file access property list")
-
-                if(NULL == (new_plist = (H5P_genplist_t *)H5I_object(*plist_id)))
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a property list")
-                break;
-            }
-
-        /* H5Fget_create_plist */
-        case H5VL_FILE_GET_FCPL:
-            {
-                H5P_genplist_t *plist;      /* Property list */
-                hid_t          *plist_id = HDva_arg(arguments, hid_t *);
-
-                f = (H5F_t *)obj;
-                if(NULL == (plist = (H5P_genplist_t *)H5I_object(f->shared->fcpl_id)))
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a property list")
-
-                /* Create the property list object to return */
-                if((*plist_id = H5P_copy_plist(plist, TRUE)) < 0)
-                    HGOTO_ERROR(H5E_PLIST, H5E_CANTINIT, FAIL, "unable to copy file creation properties")
-
-                break;
-            }
-
-        /* H5Fget_obj_count */
-        case H5VL_FILE_GET_OBJ_COUNT:
-            {
-                unsigned    types = HDva_arg(arguments, unsigned);
-                ssize_t    *ret = HDva_arg(arguments, ssize_t *);
-                size_t      obj_count = 0;      /* Number of opened objects */
-
-                f = (H5F_t *)obj;
-                /* Perform the query */
-                if(H5F_get_obj_count(f, types, TRUE, &obj_count) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_BADITER, FAIL, "H5F_get_obj_count failed")
-
-                /* Set the return value */
-                *ret = (ssize_t)obj_count;
-                break;
-            }
-
-        /* H5Fget_obj_ids */
-        case H5VL_FILE_GET_OBJ_IDS:
-            {
-                unsigned    types = HDva_arg(arguments, unsigned);
-                size_t      max_objs = HDva_arg(arguments, size_t);
-                hid_t      *oid_list = HDva_arg(arguments, hid_t *);
-                ssize_t    *ret = HDva_arg(arguments, ssize_t *);
-                size_t      obj_count = 0;      /* Number of opened objects */
-
-                f = (H5F_t *)obj;
-                /* Perform the query */
-                if(H5F_get_obj_ids(f, types, max_objs, oid_list, TRUE, &obj_count) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_BADITER, FAIL, "H5F_get_obj_ids failed")
-
-                /* Set the return value */
-                *ret = (ssize_t)obj_count;
-                break;
-            }
-
-        /* H5Fget_intent */
-        case H5VL_FILE_GET_INTENT:
-            {
-                unsigned *intent_flags = HDva_arg(arguments, unsigned *);
-
-                f = (H5F_t *)obj;
-
-                /* HDF5 uses some flags internally that users don't know about.
-                 * Simplify things for them so that they only get either H5F_ACC_RDWR
-                 * or H5F_ACC_RDONLY and any SWMR flags.
-                 */
-                if(H5F_INTENT(f) & H5F_ACC_RDWR) {
-                    *intent_flags = H5F_ACC_RDWR;
-
-                    /* Check for SWMR write access on the file */
-                    if(H5F_INTENT(f) & H5F_ACC_SWMR_WRITE)
-                        *intent_flags |= H5F_ACC_SWMR_WRITE;
-                } /* end if */
-                else {
-                    *intent_flags = H5F_ACC_RDONLY;
-
-                    /* Check for SWMR read access on the file */
-                    if(H5F_INTENT(f) & H5F_ACC_SWMR_READ)
-                        *intent_flags |= H5F_ACC_SWMR_READ;
-                } /* end else */
-
-                break;
-            }
-
-        /* H5Fget_name */
-        case H5VL_FILE_GET_NAME:
-            {
-                H5I_type_t  type = HDva_arg(arguments, H5I_type_t);
-                size_t      size = HDva_arg(arguments, size_t);
-                char       *name = HDva_arg(arguments, char *);
-                ssize_t    *ret  = HDva_arg(arguments, ssize_t *);
-                size_t      len;
-
-                if(NULL == (f = H5F__get_file(obj, type)))
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-                len = HDstrlen(H5F_OPEN_NAME(f));
-
-                if(name) {
-                    HDstrncpy(name, H5F_OPEN_NAME(f), MIN(len + 1,size));
-                    if(len >= size)
-                        name[size-1]='\0';
-                } /* end if */
-
-                /* Set the return value for the API call */
-                *ret = (ssize_t)len;
-                break;
-            }
-
-        default:
-            HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't get this type of information")
-    } /* end switch */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_file_get() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_file_specific
- *
- * Purpose:	Specific operation on file
- *
- * Return:      SUCCEED/FAIL
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_file_specific(void *obj, H5VL_file_specific_t specific_type,
-    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
-{
-    herr_t       ret_value = SUCCEED;    /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    switch(specific_type) {
-        /* H5Fflush */
-        case H5VL_FILE_FLUSH:
-            {
-                H5I_type_t      type = HDva_arg(arguments, H5I_type_t);
-                H5F_scope_t     scope = HDva_arg(arguments, H5F_scope_t);
-                H5F_t	       *f = NULL;              /* File to flush */
-
-                /* Get the file for the object */
-                if(NULL == (f = H5F__get_file(obj, type)))
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-                /* Nothing to do if the file is read only. This determination is
-                 * made at the shared open(2) flags level, implying that opening a
-                 * file twice, once for read-only and once for read-write, and then
-                 * calling H5Fflush() with the read-only handle, still causes data
-                 * to be flushed.
-                 */
-                 if(H5F_ACC_RDWR & H5F_INTENT(f)) {
-                     /* Flush other files, depending on scope */
-                     if(H5F_SCOPE_GLOBAL == scope) {
-                         /* Call the flush routine for mounted file hierarchies */
-                         if(H5F_flush_mounts(f) < 0)
-                             HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush mounted file hierarchy")
-                     } /* end if */
-                     else {
-                         /* Call the flush routine, for this file */
-                         if(H5F__flush(f) < 0)
-                             HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush file's cached information")
-                     } /* end else */
-                 } /* end if */
-                break;
-            }
-
-        /* H5Freopen */
-        case H5VL_FILE_REOPEN:
-            {
-                void   **ret        = HDva_arg(arguments, void **);
-                H5F_t  *new_file    = NULL;
-
-                /* Reopen the file through the VOL connector */
-                if(NULL == (new_file = H5F__reopen((H5F_t *)obj)))
-                    HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to reopen file")
-                new_file->id_exists = TRUE;
-
-                *ret = (void *)new_file;
-                break;
-            }
-
-        /* H5Fmount */
-        case H5VL_FILE_MOUNT:
-            {
-                H5I_type_t  type       = HDva_arg(arguments, H5I_type_t);
-                const char *name       = HDva_arg(arguments, const char *);
-                H5F_t      *child      = HDva_arg(arguments, H5F_t *);
-                hid_t       plist_id   = HDva_arg(arguments, hid_t);
-                H5G_loc_t   loc;
-
-                if(H5G_loc_real(obj, type, &loc) < 0)
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-                /* Do the mount */
-                if(H5F__mount(&loc, name, child, plist_id) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "unable to mount file")
-
-                break;
-            }
-
-        /* H5Funmount */
-        case H5VL_FILE_UNMOUNT:
-            {
-                H5I_type_t  type       = HDva_arg(arguments, H5I_type_t);
-                const char *name       = HDva_arg(arguments, const char *);
-                H5G_loc_t   loc;
-
-                if(H5G_loc_real(obj, type, &loc) < 0)
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-                /* Unmount */
-                if(H5F__unmount(&loc, name) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "unable to unmount file")
-
-                break;
-            }
-
-        /* H5Fis_accessible */
-        case H5VL_FILE_IS_ACCESSIBLE:
-            {
-                hid_t       fapl_id = HDva_arg(arguments, hid_t);
-                const char *name    = HDva_arg(arguments, const char *);
-                htri_t     *ret     = HDva_arg(arguments, htri_t *);
-
-                /* Call private routine */
-                if((*ret = H5F__is_hdf5(name, fapl_id)) < 0)
-                    HGOTO_ERROR(H5E_IO, H5E_CANTINIT, FAIL, "error in HDF5 file check")
-                break;
-            }
-
-        default:
-            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "invalid specific operation")
-    } /* end switch */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_file_specific() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_file_optional
- *
- * Purpose:     Perform a connector-specific operation on a native file
- *
- * Return:      SUCCEED/FAIL
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_file_optional(void *obj, hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
-{
-    H5F_t *f = NULL;           /* File */
-    H5VL_native_file_optional_t optional_type = HDva_arg(arguments, H5VL_native_file_optional_t);
-    herr_t ret_value = SUCCEED;    /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    f = (H5F_t *)obj;
-    switch(optional_type) {
-        /* H5Fget_filesize */
-        case H5VL_NATIVE_FILE_GET_SIZE:
-            {
-                haddr_t     max_eof_eoa;            /* Maximum of the EOA & EOF */
-                haddr_t     base_addr;              /* Base address for the file */
-                hsize_t    *size = HDva_arg(arguments, hsize_t *);
-
-                /* Go get the actual file size */
-                if(H5F__get_max_eof_eoa(f, &max_eof_eoa) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "file can't get max eof/eoa ")
-
-                base_addr = H5FD_get_base_addr(f->shared->lf);
-
-                if(size)
-                    *size = (hsize_t)(max_eof_eoa + base_addr);     /* Convert relative base address for file to absolute address */
-
-                break;
-            }
-
-        /* H5Fget_file_image */
-        case H5VL_NATIVE_FILE_GET_FILE_IMAGE:
-            {
-                void       *buf_ptr   = HDva_arg(arguments, void *);
-                ssize_t    *ret       = HDva_arg(arguments, ssize_t *);
-                size_t      buf_len   = HDva_arg(arguments, size_t );
-
-                /* Do the actual work */
-                if((*ret = H5F__get_file_image(f, buf_ptr, buf_len)) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "get file image failed")
-                break;
-            }
-
-        /* H5Fget_freespace */
-        case H5VL_NATIVE_FILE_GET_FREE_SPACE:
-            {
-                hsize_t	tot_space;	/* Amount of free space in the file */
-                hssize_t    *ret = HDva_arg(arguments, hssize_t *);
-
-                /* Go get the actual amount of free space in the file */
-                if(H5MF_get_freespace(f, &tot_space, NULL) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to check free space for file")
-                *ret = (hssize_t)tot_space;
-                break;
-            }
-
-        /* H5Fget_free_sections */
-        case H5VL_NATIVE_FILE_GET_FREE_SECTIONS:
-            {
-                H5F_sect_info_t *sect_info = HDva_arg(arguments, H5F_sect_info_t *);
-                ssize_t         *ret       = HDva_arg(arguments, ssize_t *);
-                H5F_mem_t       type       = HDva_arg(arguments, H5F_mem_t);
-                size_t          nsects     = HDva_arg(arguments, size_t);
-
-                /* Go get the free-space section information in the file */
-                if((*ret = H5MF_get_free_sections(f, type, nsects, sect_info)) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to check free space for file")
-                break;
-            }
-
-        /* H5Fget_info1/2 */
-        case H5VL_NATIVE_FILE_GET_INFO:
-            {
-                H5I_type_t  type   = HDva_arg(arguments, H5I_type_t);
-                H5F_info2_t *finfo = HDva_arg(arguments, H5F_info2_t *);
-
-                /* Get the file struct. This call is careful to not return the file pointer
-                 * for the top file in a mount hierarchy.
-                 */
-                if(NULL == (f = H5F__get_file(obj, type)))
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "could not get a file struct")
-
-                /* Get the file info */
-                if(H5F__get_info(f, finfo) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to retrieve file info")
-
-                break;
-            }
-
-        /* H5Fget_mdc_config */
-        case H5VL_NATIVE_FILE_GET_MDC_CONF:
-            {
-                H5AC_cache_config_t *config_ptr = HDva_arg(arguments, H5AC_cache_config_t *);
-
-                /* Go get the resize configuration */
-                if(H5AC_get_cache_auto_resize_config(f->shared->cache, config_ptr) < 0)
-                    HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "H5AC_get_cache_auto_resize_config() failed.")
-                break;
-            }
-
-        /* H5Fget_mdc_hit_rate */
-        case H5VL_NATIVE_FILE_GET_MDC_HR:
-            {
-                double *hit_rate_ptr = HDva_arg(arguments, double *);
-
-                /* Go get the current hit rate */
-                if(H5AC_get_cache_hit_rate(f->shared->cache, hit_rate_ptr) < 0)
-                    HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "H5AC_get_cache_hit_rate() failed.")
-                break;
-            }
-
-        /* H5Fget_mdc_size */
-        case H5VL_NATIVE_FILE_GET_MDC_SIZE:
-            {
-                size_t *max_size_ptr        = HDva_arg(arguments, size_t *);
-                size_t *min_clean_size_ptr  = HDva_arg(arguments, size_t *);
-                size_t *cur_size_ptr        = HDva_arg(arguments, size_t *); 
-                int    *cur_num_entries_ptr = HDva_arg(arguments, int *); 
-                uint32_t cur_num_entries;
-
-                /* Go get the size data */
-                if(H5AC_get_cache_size(f->shared->cache, max_size_ptr, min_clean_size_ptr, 
-                                       cur_size_ptr, &cur_num_entries) < 0)
-                    HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "H5AC_get_cache_size() failed.")
-
-                if(cur_num_entries_ptr != NULL)
-                    *cur_num_entries_ptr = (int)cur_num_entries;
-                break;
-            }
-
-        /* H5Fget_vfd_handle */
-        case H5VL_NATIVE_FILE_GET_VFD_HANDLE:
-            {
-                void **file_handle  = HDva_arg(arguments, void **);
-                hid_t  fapl_id      = HDva_arg(arguments, hid_t);
-
-                /* Retrieve the VFD handle for the file */
-                if(H5F_get_vfd_handle(f, fapl_id, file_handle) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't retrieve VFD handle")
-                break;
-            }
-
-        /* H5Iget_file_id */
-        case H5VL_NATIVE_FILE_GET_FILE_ID:
-            {
-                H5I_type_t  type = HDva_arg(arguments, H5I_type_t);
-                hid_t      *file_id = HDva_arg(arguments, hid_t *);
-
-                if(NULL == (f = H5F__get_file(obj, type)))
-                    HGOTO_ERROR(H5E_FILE, H5E_BADTYPE, FAIL, "not a file or file object")
-                if((*file_id = H5F__get_file_id(f)) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't get file ID")
-                break;
-            }
-
-        /* H5Fclear_elink_file_cache */
-        case H5VL_NATIVE_FILE_CLEAR_ELINK_CACHE:
-            {
-                /* Release the EFC */
-                if(f->shared->efc)
-                    if(H5F__efc_release(f->shared->efc) < 0)
-                        HGOTO_ERROR(H5E_FILE, H5E_CANTRELEASE, FAIL, "can't release external file cache")
-                break;
-            }
-
-        /* H5Freset_mdc_hit_rate_stats */
-        case H5VL_NATIVE_FILE_RESET_MDC_HIT_RATE:
-            {
-                /* Reset the hit rate statistic */
-                if(H5AC_reset_cache_hit_rate_stats(f->shared->cache) < 0)
-                    HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "can't reset cache hit rate")
-                break;
-            }
-
-        /* H5Fset_mdc_config */
-        case H5VL_NATIVE_FILE_SET_MDC_CONFIG:
-            {
-                H5AC_cache_config_t *config_ptr = HDva_arg(arguments, H5AC_cache_config_t *);
-
-                /* set the resize configuration  */
-                if(H5AC_set_cache_auto_resize_config(f->shared->cache, config_ptr) < 0)
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "H5AC_set_cache_auto_resize_config() failed")
-                break;
-            }
-
-        /* H5Fget_metadata_read_retry_info */
-        case H5VL_NATIVE_FILE_GET_METADATA_READ_RETRY_INFO:
-            {
-                H5F_retry_info_t *info = HDva_arg(arguments, H5F_retry_info_t *);
-
-                if(H5F_get_metadata_read_retry_info(f, info) < 0)
-                    HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "can't get metadata read retry info")
-
-                break;
-            }
-
-        /* H5Fstart_swmr_write */
-        case H5VL_NATIVE_FILE_START_SWMR_WRITE:
-            {
-                if(H5F__start_swmr_write(f) < 0)
-                    HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "can't start SWMR write")
-
-                break;
-            }
-
-        /* H5Fstart_mdc_logging */
-        case H5VL_NATIVE_FILE_START_MDC_LOGGING:
-            {
-                /* Call mdc logging function */
-                if(H5C_start_logging(f->shared->cache) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_LOGFAIL, FAIL, "unable to start mdc logging")
-
-                break;
-            }
-
-        /* H5Fstop_mdc_logging */
-        case H5VL_NATIVE_FILE_STOP_MDC_LOGGING:
-            {
-                /* Call mdc logging function */
-                if(H5C_stop_logging(f->shared->cache) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_LOGFAIL, FAIL, "unable to stop mdc logging")
-
-                break;
-            }
-
-        /* H5Fget_mdc_logging_status */
-        case H5VL_NATIVE_FILE_GET_MDC_LOGGING_STATUS:
-            {
-                hbool_t *is_enabled				= HDva_arg(arguments, hbool_t *);
-                hbool_t *is_currently_logging	= HDva_arg(arguments, hbool_t *);
-
-                /* Call mdc logging function */
-                if(H5C_get_logging_status(f->shared->cache, is_enabled, is_currently_logging) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_LOGFAIL, FAIL, "unable to get logging status")
-
-                break;
-            }
-
-        /* H5Fformat_convert */
-        case H5VL_NATIVE_FILE_FORMAT_CONVERT:
-            {
-                /* Convert the format */
-                if(H5F__format_convert(f) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_CANTCONVERT, FAIL, "can't convert file format")
-
-                break;
-            }
-
-        /* H5Freset_page_buffering_stats */
-        case H5VL_NATIVE_FILE_RESET_PAGE_BUFFERING_STATS:
-            {
-                /* Sanity check */
-                if(NULL == f->shared->page_buf)
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "page buffering not enabled on file")
-
-                /* Reset the statistics */
-                if (H5PB_reset_stats(f->shared->page_buf) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't reset stats for page buffering")
-
-                break;
-            }
-
-        /* H5Fget_page_buffering_stats */
-        case H5VL_NATIVE_FILE_GET_PAGE_BUFFERING_STATS:
-            {
-                unsigned *accesses      = HDva_arg(arguments, unsigned *);
-                unsigned *hits          = HDva_arg(arguments, unsigned *);
-                unsigned *misses        = HDva_arg(arguments, unsigned *);
-                unsigned *evictions     = HDva_arg(arguments, unsigned *);
-                unsigned *bypasses      = HDva_arg(arguments, unsigned *);
-                
-                /* Sanity check */
-                if(NULL == f->shared->page_buf)
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "page buffering not enabled on file")
-
-                /* Get the statistics */
-                if(H5PB_get_stats(f->shared->page_buf, accesses, hits, misses, evictions, bypasses) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't retrieve stats for page buffering")
-
-                break;
-            }
-
-        /* H5Fget_mdc_image_info */
-        case H5VL_NATIVE_FILE_GET_MDC_IMAGE_INFO:
-            {
-                haddr_t *image_addr = HDva_arg(arguments, haddr_t *);
-                hsize_t *image_len = HDva_arg(arguments, hsize_t *);
-
-                /* Go get the address and size of the cache image */
-                if(H5AC_get_mdc_image_info(f->shared->cache, image_addr, image_len) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't retrieve cache image info")
-
-                break;
-            }
-
-        /* H5Fget_eoa */
-        case H5VL_NATIVE_FILE_GET_EOA:
-            {
-                haddr_t *eoa = HDva_arg(arguments, haddr_t *);
-                haddr_t rel_eoa;        /* Relative address of EOA */
-
-                /* Sanity check */
-                HDassert(eoa);
-
-                /* This routine will work only for drivers with this feature enabled.*/
-                /* We might introduce a new feature flag in the future */
-                if(!H5F_HAS_FEATURE(f, H5FD_FEAT_SUPPORTS_SWMR_IO))
-                    HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "must use a SWMR-compatible VFD for this public routine")
-
-                /* The real work */
-                if(HADDR_UNDEF == (rel_eoa = H5F_get_eoa(f, H5FD_MEM_DEFAULT)))
-                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "get_eoa request failed")
-
-                /* Set return value */
-                /* (Note compensating for base address subtraction in internal routine) */
-                *eoa = rel_eoa + H5F_get_base_addr(f);
-
-                break;
-            }
-
-        /* H5Fincrement_filesize */
-        case H5VL_NATIVE_FILE_INCR_FILESIZE:
-            {
-                hsize_t increment = HDva_arg(arguments, hsize_t);
-                haddr_t max_eof_eoa;        /* Maximum of the relative EOA & EOF */
-
-                /* This public routine will work only for drivers with this feature enabled.*/
-                /* We might introduce a new feature flag in the future */
-                if(!H5F_HAS_FEATURE(f, H5FD_FEAT_SUPPORTS_SWMR_IO))
-                    HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "must use a SWMR-compatible VFD for this public routine")
-
-                /* Get the maximum of EOA and EOF */
-                if(H5F__get_max_eof_eoa(f, &max_eof_eoa) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "file can't get max eof/eoa ")
-
-                /* Set EOA to the maximum value + increment */
-                if(H5F__set_eoa(f, H5FD_MEM_DEFAULT, max_eof_eoa + increment) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "driver set_eoa request failed")
-
-                break;
-            }
-
-        /* H5Fset_latest_format, H5Fset_libver_bounds */
-        case H5VL_NATIVE_FILE_SET_LIBVER_BOUNDS:
-            {
-                H5F_libver_t low = HDva_arg(arguments, H5F_libver_t);
-                H5F_libver_t high = HDva_arg(arguments, H5F_libver_t);
-
-                /* Call internal set_libver_bounds function */
-                if(H5F__set_libver_bounds(f, low, high) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "cannot set low/high bounds")
-
-                break;
-            }
-
-        default:
-            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "invalid optional operation")
-    } /* end switch */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_file_optional() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_file_close
- *
- * Purpose:     Closes a file.
- *
- * Return:      SUCCEED/FAIL (the file will not be closed on failure)
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_file_close(void *file, hid_t H5_ATTR_UNUSED dxpl_id,
-    void H5_ATTR_UNUSED **req)
-{
-    int     nref;
-    H5F_t   *f          = (H5F_t *)file;
-    hid_t   file_id     = H5I_INVALID_HID;
-    herr_t  ret_value   = SUCCEED;                  /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    /* This routine should only be called when a file ID's ref count drops to zero */
-    HDassert(H5F_ID_EXISTS(f));
-
-    /* Flush file if this is the last reference to this id and we have write
-     * intent, unless it will be flushed by the "shared" file being closed.
-     * This is only necessary to replicate previous behaviour, and could be
-     * disabled by an option/property to improve performance.
-     */
-    if((H5F_NREFS(f) > 1) && (H5F_INTENT(f) & H5F_ACC_RDWR)) {
-        /* Get the file ID corresponding to the H5F_t struct */
-        if(H5I_find_id(f, H5I_FILE, &file_id) < 0 || H5I_INVALID_HID == file_id)
-            HGOTO_ERROR(H5E_ATOM, H5E_CANTGET, FAIL, "invalid atom")
-
-        /* Get the number of references outstanding for this file ID */
-        if((nref = H5I_get_ref(file_id, FALSE)) < 0)
-            HGOTO_ERROR(H5E_ATOM, H5E_CANTGET, FAIL, "can't get ID ref count")
-        if(nref == 1)
-            if(H5F__flush(f) < 0)
-                HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "unable to flush cache")
-    } /* end if */
-
-    /* Close the file */
-    if(H5F__close(f) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTDEC, FAIL, "can't close file")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_file_close() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_group_create
- *
- * Purpose:     Creates a group inside a native h5 file.
- *
- * Return:      Success:    Pointer to a group struct
- *
- *              Failure:    NULL
- *
- *-------------------------------------------------------------------------
- */
-static void *
-H5VL__native_group_create(void *obj, const H5VL_loc_params_t *loc_params, const char *name,
-    hid_t gcpl_id, hid_t H5_ATTR_UNUSED gapl_id, hid_t H5_ATTR_UNUSED dxpl_id,
-    void H5_ATTR_UNUSED **req)
-{
-    H5P_genplist_t *plist;              /* Property list pointer        */
-    H5G_loc_t       loc;                /* Location to create group     */
-    H5G_t          *grp = NULL;         /* New group created            */
-    hid_t           lcpl_id;
-    void           *ret_value;
-
-    FUNC_ENTER_STATIC
-
-    /* Get the property list structure */
-    if(NULL == (plist = (H5P_genplist_t *)H5I_object(gcpl_id)))
-        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, NULL, "can't find object for ID")
-
-    /* Get creation properties */
-    if(H5P_get(plist, H5VL_PROP_GRP_LCPL_ID, &lcpl_id) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get property value for lcpl id")
-
-    /* Set up the location */
-    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file or file object")
-
-    /* if name is NULL then this is from H5Gcreate_anon */
-    if(name == NULL) {
-        H5G_obj_create_t gcrt_info;         /* Information for group creation */
-
-        /* Set up group creation info */
-        gcrt_info.gcpl_id = gcpl_id;
-        gcrt_info.cache_type = H5G_NOTHING_CACHED;
-        HDmemset(&gcrt_info.cache, 0, sizeof(gcrt_info.cache));
-
-        /* Create the new group & get its ID */
-        if(NULL == (grp = H5G__create(loc.oloc->file, &gcrt_info)))
-            HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, NULL, "unable to create group")            
-    } /* end if */
-    /* otherwise it's from H5Gcreate */
-    else {
-        /* Create the new group & get its ID */
-        if(NULL == (grp = H5G__create_named(&loc, name, lcpl_id, gcpl_id)))
-            HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, NULL, "unable to create group")
-    } /* end else */
-
-    ret_value = (void *)grp;
-
-done:
-    if(name == NULL) {
-        /* Release the group's object header, if it was created */
-        if(grp) {
-            H5O_loc_t *oloc;         /* Object location for group */
-
-            /* Get the new group's object location */
-            if(NULL == (oloc = H5G_oloc(grp)))
-                HDONE_ERROR(H5E_SYM, H5E_CANTGET, NULL, "unable to get object location of group")
-
-            /* Decrement refcount on group's object header in memory */
-            if(H5O_dec_rc_by_loc(oloc) < 0)
-                HDONE_ERROR(H5E_SYM, H5E_CANTDEC, NULL, "unable to decrement refcount on newly created object")
-         } /* end if */
-    } /* end if */
-
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_group_create() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_group_open
- *
- * Purpose:     Opens a group inside a native h5 file.
- *
- * Return:      Success:    Pointer to a group struct
- *
- *              Failure:    NULL
- *
- *-------------------------------------------------------------------------
- */
-static void *
-H5VL__native_group_open(void *obj, const H5VL_loc_params_t *loc_params, const char *name, 
-    hid_t H5_ATTR_UNUSED gapl_id, hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
-{
-    H5G_loc_t       loc;                /* Location to open group   */
-    H5G_t          *grp = NULL;         /* New group opend          */
-    void           *ret_value;
-
-    FUNC_ENTER_STATIC
-
-    /* Set up the location */
-    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file or file object")
-
-    /* Open the group */
-    if((grp = H5G__open_name(&loc, name)) == NULL)
-        HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, NULL, "unable to open group")
-
-    ret_value = (void *)grp;
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_group_open() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_group_get
- *
- * Purpose:     Get info about a group
- *
- * Return:      SUCCEED/FAIL
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_group_get(void *obj, H5VL_group_get_t get_type,
-    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
-{
-    herr_t      ret_value = SUCCEED;    /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    switch(get_type) {
-        /* H5Gget_create_plist */
-        case H5VL_GROUP_GET_GCPL:
-            {
-                hid_t      *new_gcpl_id     = HDva_arg(arguments, hid_t *);
-                H5G_t      *grp             = (H5G_t *)obj;
-
-                if((*new_gcpl_id = H5G_get_create_plist(grp)) < 0)
-                    HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get creation property list for group")
-                break;
-            }
-
-        /* H5Gget_info */
-        case H5VL_GROUP_GET_INFO:
-            {
-                const H5VL_loc_params_t  *loc_params  = HDva_arg(arguments, const H5VL_loc_params_t *);
-                H5G_info_t         *group_info  = HDva_arg(arguments, H5G_info_t *);
-                H5G_loc_t           loc;
-
-                if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-                if(loc_params->type == H5VL_OBJECT_BY_SELF) {
-                    /* H5Gget_info */
-
-                    /* Retrieve the group's information */
-                    if(H5G__obj_info(loc.oloc, group_info) < 0)
-                        HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't retrieve group info")
-                } /* end if */
-                else if(loc_params->type == H5VL_OBJECT_BY_NAME) {
-                    /* H5Gget_info_by_name */
-
-                    /* Retrieve the group's information */
-                    if(H5G__get_info_by_name(&loc, loc_params->loc_data.loc_by_name.name, group_info) < 0)
-                        HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't retrieve group info")
-                } /* end else-if */
-                else if(loc_params->type == H5VL_OBJECT_BY_IDX) {
-                    /* H5Gget_info_by_idx */
-
-                    /* Retrieve the group's information */
-                    if(H5G__get_info_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, loc_params->loc_data.loc_by_idx.idx_type,
-                            loc_params->loc_data.loc_by_idx.order, loc_params->loc_data.loc_by_idx.n, group_info) < 0)
-                        HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't retrieve group info")
-                } /* end else-if */
-                else
-                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown get info parameters")
-                break;
-            }
-
-        default:
-            HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't get this type of information from group")
-    } /* end switch */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_group_get() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_group_specific
- *
- * Purpose:     Specific operations for groups
- *
- * Return:      SUCCEED/FAIL
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_group_specific(void *obj, H5VL_group_specific_t specific_type, 
-                             hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
-{
-    H5G_t       *grp = (H5G_t *)obj;
-    herr_t       ret_value = SUCCEED;    /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    switch(specific_type) {
-        case H5VL_GROUP_FLUSH:
-            {
-                hid_t group_id = HDva_arg(arguments, hid_t);
-
-                /* Flush object's metadata to file */
-                if(H5O_flush_common(&grp->oloc, group_id) < 0)
-                    HGOTO_ERROR(H5E_SYM, H5E_CANTFLUSH, FAIL, "unable to flush group")
-
-                break;
-            }
-
-        case H5VL_GROUP_REFRESH:
-            {
-                hid_t group_id = HDva_arg(arguments, hid_t);
-
-                /* Call private function to refresh group object */
-                if((H5O_refresh_metadata(group_id, grp->oloc)) < 0)
-                    HGOTO_ERROR(H5E_SYM, H5E_CANTLOAD, FAIL, "unable to refresh group")
-
-                break;
-            }
-
-        default:
-            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "invalid specific operation")
-    } /* end switch */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_group_specific() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_group_optional
- *
- * Purpose:     Perform a connector-specific operation on a native group
- *
- * Return:      SUCCEED/FAIL
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_group_optional(void *obj, hid_t H5_ATTR_UNUSED dxpl_id,
-    void H5_ATTR_UNUSED **req, va_list arguments)
-{
-    H5VL_native_group_optional_t optional_type;
-    herr_t ret_value = SUCCEED;    /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    optional_type = HDva_arg(arguments, H5VL_native_group_optional_t);
-    switch(optional_type) {
-#ifndef H5_NO_DEPRECATED_SYMBOLS
-        /* H5Giterate (deprecated) */
-        case H5VL_NATIVE_GROUP_ITERATE_OLD:
-            {
-                const H5VL_loc_params_t *loc_params = HDva_arg(arguments, const H5VL_loc_params_t *);
-                hsize_t idx = HDva_arg(arguments, hsize_t);
-                hsize_t *last_obj = HDva_arg(arguments, hsize_t *);
-                const H5G_link_iterate_t *lnk_op = HDva_arg(arguments, const H5G_link_iterate_t *);
-                void *op_data = HDva_arg(arguments, void *);
-                H5G_loc_t grp_loc;
-
-                /* Get the location struct for the object */
-                if(H5G_loc_real(obj, loc_params->obj_type, &grp_loc) < 0)
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-                /* Call the actual iteration routine */
-                if((ret_value = H5G_iterate(&grp_loc, loc_params->loc_data.loc_by_name.name, H5_INDEX_NAME, H5_ITER_INC, idx, last_obj, lnk_op, op_data)) < 0)
-                    HERROR(H5E_VOL, H5E_BADITER, "error iterating over group's links");
-
-                break;
-            }
-
-        /* H5Gget_objinfo (deprecated) */
-        case H5VL_NATIVE_GROUP_GET_OBJINFO:
-            {
-                const H5VL_loc_params_t *loc_params = HDva_arg(arguments, const H5VL_loc_params_t *);
-                hbool_t follow_link = HDva_arg(arguments, unsigned);
-                H5G_stat_t *statbuf = HDva_arg(arguments, H5G_stat_t *);
-                H5G_loc_t grp_loc;
-
-                /* Get the location struct for the object */
-                if(H5G_loc_real(obj, loc_params->obj_type, &grp_loc) < 0)
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-                /* Call the actual group objinfo routine */
-                if(H5G__get_objinfo(&grp_loc, loc_params->loc_data.loc_by_name.name, follow_link, statbuf) < 0)
-                    HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "cannot stat object")
-
-                break;
-            }
-#else
-        /* XXX: These cases only exist because they are the only group optional
-         *      values and we can't have empty enums. Delete them when we have
-         *      non-deprecated group optional enum values.
-         */
-        case H5VL_NATIVE_GROUP_ITERATE_OLD:
-            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "H5VL_NATIVE_GROUP_ITERATE_OLD is not a valid value when the library is built without deprecated routines")
-        case H5VL_NATIVE_GROUP_GET_OBJINFO:
-            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "H5VL_NATIVE_GROUP_GET_OBJINFO is not a valid value when the library is built without deprecated routines")
-#endif /* H5_NO_DEPRECATED_SYMBOLS */
-
-        default:
-            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "invalid optional operation")
-    } /* end switch */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_group_optional() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_group_close
- *
- * Purpose:     Closes a group.
- *
- * Return:      SUCCEED/FAIL (the group will not be closed on failure)
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_group_close(void *grp, hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
-{
-    herr_t ret_value = SUCCEED;                 /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    if(H5G_close((H5G_t *)grp) < 0)
-        HGOTO_ERROR(H5E_SYM, H5E_CLOSEERROR, FAIL, "can't close group")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_group_close() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5VL__native_link_create
- *
- * Purpose:	Creates an hard/soft/UD/external links.
- *
- * Return:	Non-negative on success/Negative on failure
- *
- * Programmer:  Mohamad Chaarawi
- *              April, 2012
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_link_create(H5VL_link_create_type_t create_type, void *obj,
-    const H5VL_loc_params_t *loc_params, hid_t lcpl_id, hid_t H5_ATTR_UNUSED lapl_id,
-    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
-{
-    H5P_genplist_t   *plist;                     /* Property list pointer */
-    herr_t           ret_value = SUCCEED;        /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    /* Get the plist structure */
-    if(NULL == (plist = (H5P_genplist_t *)H5I_object(lcpl_id)))
-        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID");
-
-    switch(create_type) {
-        case H5VL_LINK_CREATE_HARD:
-            {
-                H5G_loc_t    cur_loc;
-                H5G_loc_t    link_loc;
-                void         *cur_obj;
-                H5VL_loc_params_t cur_params;
-
-                if(H5P_get(plist, H5VL_PROP_LINK_TARGET, &cur_obj) < 0)
-                    HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get property value for current location id")
-                if(H5P_get(plist, H5VL_PROP_LINK_TARGET_LOC_PARAMS, &cur_params) < 0)
-                    HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get property value for current name")
-
-                if(NULL != cur_obj && H5G_loc_real(cur_obj, cur_params.obj_type, &cur_loc) < 0)
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-                if(NULL != obj && H5G_loc_real(obj, loc_params->obj_type, &link_loc) < 0)
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-                /* H5Lcreate_hard */
-                if(H5VL_OBJECT_BY_NAME == cur_params.type) {
-                    H5G_loc_t *cur_loc_p, *link_loc_p;
-
-                    /* Set up current & new location pointers */
-                    cur_loc_p = &cur_loc;
-                    link_loc_p = &link_loc;
-                    if(NULL == cur_obj)
-                        cur_loc_p = link_loc_p;
-                    else if(NULL == obj)
-                        link_loc_p = cur_loc_p;
-                    else if(cur_loc_p->oloc->file != link_loc_p->oloc->file)
-                        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "source and destination should be in the same file.")
-
-                    /* Create the link */
-                    if((ret_value = H5L_create_hard(cur_loc_p, cur_params.loc_data.loc_by_name.name, 
-                                                    link_loc_p, loc_params->loc_data.loc_by_name.name, lcpl_id)) < 0)
-                        HGOTO_ERROR(H5E_LINK, H5E_CANTINIT, FAIL, "unable to create link")
-                } /* end if */
-                else { /* H5Olink */
-                    /* Link to the object */
-                    if(H5L_link(&link_loc, loc_params->loc_data.loc_by_name.name, &cur_loc, lcpl_id) < 0)
-                        HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, FAIL, "unable to create link")
-                } /* end else */
-                break;
-            }
-
-        case H5VL_LINK_CREATE_SOFT:
-            {
-                char        *target_name;
-                H5G_loc_t   link_loc;               /* Group location for new link */
-
-                if(H5G_loc_real(obj, loc_params->obj_type, &link_loc) < 0)
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-                if(H5P_get(plist, H5VL_PROP_LINK_TARGET_NAME, &target_name) < 0)
-                    HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get property value for targe name")
-
-                /* Create the link */
-                if((ret_value = H5L_create_soft(target_name, &link_loc, loc_params->loc_data.loc_by_name.name, lcpl_id)) < 0)
-                    HGOTO_ERROR(H5E_LINK, H5E_CANTINIT, FAIL, "unable to create link")
-                break;
-            }
-
-        case H5VL_LINK_CREATE_UD:
-            {
-                H5G_loc_t   link_loc;               /* Group location for new link */
-                H5L_type_t link_type;
-                void *udata;
-                size_t udata_size;
-
-                if(H5G_loc_real(obj, loc_params->obj_type, &link_loc) < 0)
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-                if(H5P_get(plist, H5VL_PROP_LINK_TYPE, &link_type) < 0)
-                    HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get property value for link type")
-                if(H5P_get(plist, H5VL_PROP_LINK_UDATA, &udata) < 0)
-                    HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get property value for udata")
-                if(H5P_get(plist, H5VL_PROP_LINK_UDATA_SIZE, &udata_size) < 0)
-                    HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get property value for udata size")
-
-                /* Create link */
-                if(H5L__create_ud(&link_loc, loc_params->loc_data.loc_by_name.name, udata, udata_size, 
-                                 link_type, lcpl_id) < 0)
-                    HGOTO_ERROR(H5E_LINK, H5E_CANTINIT, FAIL, "unable to create link")
-                break;
-            }
-
-        default:
-            HGOTO_ERROR(H5E_LINK, H5E_CANTINIT, FAIL, "invalid link creation call")
-    } /* end switch */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_link_create() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5VL__native_link_copy
- *
- * Purpose:	Renames an object within an HDF5 file and copies it to a new
- *              group.  The original name SRC is unlinked from the group graph
- *              and then inserted with the new name DST (which can specify a
- *              new path for the object) as an atomic operation. The names
- *              are interpreted relative to SRC_LOC_ID and
- *              DST_LOC_ID, which are either file IDs or group ID.
- *
- * Return:	Non-negative on success/Negative on failure
- *
- * Programmer:  Mohamad Chaarawi
- *              April, 2012
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_link_copy(void *src_obj, const H5VL_loc_params_t *loc_params1, 
-    void *dst_obj, const H5VL_loc_params_t *loc_params2, hid_t lcpl_id,
-    hid_t H5_ATTR_UNUSED lapl_id, hid_t H5_ATTR_UNUSED dxpl_id,
-    void H5_ATTR_UNUSED **req)
-{
-    H5G_loc_t	src_loc, *src_loc_p;
-    H5G_loc_t	dst_loc, *dst_loc_p;
-    herr_t      ret_value = SUCCEED;        /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    if(NULL != src_obj && H5G_loc_real(src_obj, loc_params1->obj_type, &src_loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-    if(NULL != dst_obj && H5G_loc_real(dst_obj, loc_params2->obj_type, &dst_loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-    /* Set up src & dst location pointers */
-    src_loc_p = &src_loc;
-    dst_loc_p = &dst_loc;
-    if(NULL == src_obj)
-        src_loc_p = dst_loc_p;
-    else if(NULL == dst_obj)
-        dst_loc_p = src_loc_p;
-
-    /* Copy the link */
-    if(H5L_move(src_loc_p, loc_params1->loc_data.loc_by_name.name, 
-                dst_loc_p, loc_params2->loc_data.loc_by_name.name, 
-                TRUE, lcpl_id) < 0)
-        HGOTO_ERROR(H5E_LINK, H5E_CANTCOPY, FAIL, "unable to copy link")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_link_copy() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5VL__native_link_move
- *
- * Purpose:	Renames an object within an HDF5 file and moves it to a new
- *              group.  The original name SRC is unlinked from the group graph
- *              and then inserted with the new name DST (which can specify a
- *              new path for the object) as an atomic operation. The names
- *              are interpreted relative to SRC_LOC_ID and
- *              DST_LOC_ID, which are either file IDs or group ID.
- *
- * Return:	Non-negative on success/Negative on failure
- *
- * Programmer:  Mohamad Chaarawi
- *              April, 2012
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_link_move(void *src_obj, const H5VL_loc_params_t *loc_params1, 
-    void *dst_obj, const H5VL_loc_params_t *loc_params2, hid_t lcpl_id,
-    hid_t H5_ATTR_UNUSED lapl_id, hid_t H5_ATTR_UNUSED dxpl_id,
-    void H5_ATTR_UNUSED **req)
-{
-    H5G_loc_t	src_loc, *src_loc_p;
-    H5G_loc_t	dst_loc, *dst_loc_p;
-    herr_t      ret_value = SUCCEED;        /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    if(NULL != src_obj && H5G_loc_real(src_obj, loc_params1->obj_type, &src_loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-    if(NULL != dst_obj && H5G_loc_real(dst_obj, loc_params2->obj_type, &dst_loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-    /* Set up src & dst location pointers */
-    src_loc_p = &src_loc;
-    dst_loc_p = &dst_loc;
-    if(NULL == src_obj)
-        src_loc_p = dst_loc_p;
-    else if(NULL == dst_obj)
-        dst_loc_p = src_loc_p;
-
-    /* Move the link */
-    if(H5L_move(src_loc_p, loc_params1->loc_data.loc_by_name.name, 
-                dst_loc_p, loc_params2->loc_data.loc_by_name.name, 
-                FALSE, lcpl_id) < 0)
-        HGOTO_ERROR(H5E_LINK, H5E_CANTMOVE, FAIL, "unable to move link")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_link_move() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5VL__native_link_get
- *
- * Purpose:	Get info about a link
- *
- * Return:	Success:	0
- *		Failure:	-1
- *
- * Programmer:  Mohamad Chaarawi
- *              April, 2012
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_link_get(void *obj, const H5VL_loc_params_t *loc_params, H5VL_link_get_t get_type, 
-    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
-{
-    H5G_loc_t	loc;
-    herr_t      ret_value = SUCCEED;    /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-    switch(get_type) {
-        /* H5Lget_info/H5Lget_info_by_idx */
-        case H5VL_LINK_GET_INFO:
-            {
-                H5L_info_t *linfo  = HDva_arg(arguments, H5L_info_t *);
-
-                /* Get the link information */
-                if(loc_params->type == H5VL_OBJECT_BY_NAME) { /* H5Lget_info */
-                    if(H5L_get_info(&loc, loc_params->loc_data.loc_by_name.name, linfo) < 0)
-                        HGOTO_ERROR(H5E_LINK, H5E_NOTFOUND, FAIL, "unable to get link info")
-                } /* end if */
-                else if(loc_params->type == H5VL_OBJECT_BY_IDX) { /* H5Lget_info_by_idx */
-                    if(H5L_get_info_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, loc_params->loc_data.loc_by_idx.idx_type,
-                            loc_params->loc_data.loc_by_idx.order, loc_params->loc_data.loc_by_idx.n, linfo) < 0)
-                        HGOTO_ERROR(H5E_LINK, H5E_NOTFOUND, FAIL, "unable to get link info")
-                } /* end else-if */
-                else
-                    HGOTO_ERROR(H5E_LINK, H5E_NOTFOUND, FAIL, "unable to get link info")
-                break;
-            }
-
-        /* H5Lget_name_by_idx */
-        case H5VL_LINK_GET_NAME:
-            {
-                char       *name   = HDva_arg(arguments, char *);
-                size_t      size   = HDva_arg(arguments, size_t);
-                ssize_t    *ret    = HDva_arg(arguments, ssize_t *);
-
-                /* Get the link name */
-                if((*ret = H5L_get_name_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, loc_params->loc_data.loc_by_idx.idx_type,
-                            loc_params->loc_data.loc_by_idx.order, loc_params->loc_data.loc_by_idx.n, name, size)) < 0)
-                    HGOTO_ERROR(H5E_LINK, H5E_NOTFOUND, FAIL, "unable to get link info")
-
-                break;
-            }
-
-        /* H5Lget_val/H5Lget_val_by_idx */
-        case H5VL_LINK_GET_VAL:
-            {
-                void       *buf    = HDva_arg(arguments, void *);
-                size_t     size    = HDva_arg(arguments, size_t);
-
-                /* Get the link information */
-                if(loc_params->type == H5VL_OBJECT_BY_NAME) { /* H5Lget_val */
-                    if(H5L_get_val(&loc, loc_params->loc_data.loc_by_name.name, buf, size) < 0)
-                        HGOTO_ERROR(H5E_LINK, H5E_NOTFOUND, FAIL, "unable to get link value")
-                }
-                else if(loc_params->type == H5VL_OBJECT_BY_IDX) { /* H5Lget_val_by_idx */
-
-                    if(H5L_get_val_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, loc_params->loc_data.loc_by_idx.idx_type,
-                            loc_params->loc_data.loc_by_idx.order, loc_params->loc_data.loc_by_idx.n, buf, size) < 0)
-                        HGOTO_ERROR(H5E_LINK, H5E_NOTFOUND, FAIL, "unable to get link val")                    
-                }
-                else
-                    HGOTO_ERROR(H5E_LINK, H5E_NOTFOUND, FAIL, "unable to get link val")
-
-                break;
-            }
-
-        default:
-            HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't get this type of information from link")
-    } /* end switch */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_link_get() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5VL__native_link_specific
- *
- * Purpose:	Specific operation on a link
- *
- * Return:	Success:	0
- *		Failure:	-1
- *
- * Programmer:  Mohamad Chaarawi
- *              April, 2012
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_link_specific(void *obj, const H5VL_loc_params_t *loc_params, H5VL_link_specific_t specific_type, 
-    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
-{
-    herr_t      ret_value = SUCCEED;    /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    switch(specific_type) {
-        case H5VL_LINK_EXISTS:
-            {
-                htri_t *ret = HDva_arg(arguments, htri_t *);
-                H5G_loc_t loc;
-
-                if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-                /* Check for the existence of the link */
-                if((*ret = H5L_exists(&loc, loc_params->loc_data.loc_by_name.name)) < 0)
-                    HGOTO_ERROR(H5E_LINK, H5E_NOTFOUND, FAIL, "unable to specific link info")
-                break;
-            }
-
-        case H5VL_LINK_ITER:
-            {
-                H5G_loc_t loc;
-                hbool_t recursive = HDva_arg(arguments, int);                     
-                H5_index_t idx_type = HDva_arg(arguments, H5_index_t);
-                H5_iter_order_t order = HDva_arg(arguments, H5_iter_order_t);
-                hsize_t *idx_p = HDva_arg(arguments, hsize_t *);
-                H5L_iterate_t op = HDva_arg(arguments, H5L_iterate_t);
-                void *op_data = HDva_arg(arguments, void *);
-
-                /* Get the location */
-                if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
-
-                /* Visit or iterate over the links */
-                if(loc_params->type == H5VL_OBJECT_BY_SELF) {
-                    if(recursive) {
-                        /* H5Lvisit */
-                        if((ret_value = H5G_visit(&loc, ".", idx_type, order, op, op_data)) < 0)
-                            HGOTO_ERROR(H5E_LINK, H5E_BADITER, FAIL, "link visitation failed")
-                    } /* end if */
-                    else {
-                        /* H5Literate */
-                        if((ret_value = H5L_iterate(&loc, ".", idx_type, order, idx_p, op, op_data)) < 0)
-                            HGOTO_ERROR(H5E_LINK, H5E_BADITER, FAIL, "error iterating over links")
-                    } /* end else */
-                } /* end if */
-                else if(loc_params->type == H5VL_OBJECT_BY_NAME) {
-                    if(recursive) {
-                        /* H5Lvisit_by_name */
-                        if((ret_value = H5G_visit(&loc, loc_params->loc_data.loc_by_name.name, idx_type, order, op, op_data)) < 0)
-                            HGOTO_ERROR(H5E_LINK, H5E_BADITER, FAIL, "link visitation failed")
-                    } /* end if */
-                    else {
-                        /* H5Literate_by_name */
-                        if((ret_value = H5L_iterate(&loc, loc_params->loc_data.loc_by_name.name, idx_type, order, idx_p, op, op_data)) < 0)
-                            HGOTO_ERROR(H5E_LINK, H5E_BADITER, FAIL, "error iterating over links")
-                    } /* end else */
-                } /* end else-if */
-                else
-                    HGOTO_ERROR(H5E_LINK, H5E_UNSUPPORTED, FAIL, "unknown link iterate params")
-
-                break;
-            }
-
-        case H5VL_LINK_DELETE:
-            {
-                H5G_loc_t loc;
-
-                if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-                /* Unlink */
-                if(loc_params->type == H5VL_OBJECT_BY_NAME) { /* H5Ldelete */
-                    if(H5L_delete(&loc, loc_params->loc_data.loc_by_name.name) < 0)
-                        HGOTO_ERROR(H5E_LINK, H5E_CANTDELETE, FAIL, "unable to delete link")
-                } /* end if */
-                else if(loc_params->type == H5VL_OBJECT_BY_IDX) { /* H5Ldelete_by_idx */
-                    if(H5L_delete_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, loc_params->loc_data.loc_by_idx.idx_type,
-                            loc_params->loc_data.loc_by_idx.order, loc_params->loc_data.loc_by_idx.n) < 0)
-                        HGOTO_ERROR(H5E_LINK, H5E_CANTDELETE, FAIL, "unable to delete link")
-                } /* end else-if */
-                else
-                    HGOTO_ERROR(H5E_LINK, H5E_CANTDELETE, FAIL, "unable to delete link")
-                break;
-            }
-
-        default:
-            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "invalid specific operation")
-    } /* end switch */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_link_specific() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5VL__native_object_open
- *
- * Purpose:	Opens an object inside a native h5 file.
- *
- * Return:	Success:	object id. 
- *		Failure:	NULL
- *
- * Programmer:  Mohamad Chaarawi
- *              March, 2012
- *
- *-------------------------------------------------------------------------
- */
-static void *
-H5VL__native_object_open(void *obj, const H5VL_loc_params_t *loc_params, H5I_type_t *opened_type, 
-    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
-{
-    H5G_loc_t   loc;
-    void       *ret_value = NULL;
-
-    FUNC_ENTER_STATIC
-
-    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file or file object")
-
-    switch(loc_params->type) {
-        case H5VL_OBJECT_BY_NAME:
-            {
-                /* Open the object */
-                if(NULL == (ret_value = H5O_open_name(&loc, loc_params->loc_data.loc_by_name.name, opened_type)))
-                    HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, NULL, "unable to open object by name")
-                break;
-            }
-
-        case H5VL_OBJECT_BY_IDX:
-            {
-                /* Open the object */
-                if(NULL == (ret_value = H5O_open_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, loc_params->loc_data.loc_by_idx.idx_type,
-                        loc_params->loc_data.loc_by_idx.order, loc_params->loc_data.loc_by_idx.n, opened_type)))
-                    HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, NULL, "unable to open object by index")
-                break;
-            }
-
-        case H5VL_OBJECT_BY_ADDR:
-            {
-                /* Open the object */
-                if(NULL == (ret_value = H5O_open_by_addr(&loc, loc_params->loc_data.loc_by_addr.addr, opened_type)))
-                    HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, NULL, "unable to open object by address")
-                break;
-            }
-
-        case H5VL_OBJECT_BY_REF:
-            {
-                hid_t temp_id = H5I_INVALID_HID;
-                H5F_t *file = NULL;
-
-                /* Get the file pointer from the entry */
-                file = loc.oloc->file;
-
-                /* Create reference */
-                if((temp_id = H5R__dereference(file, loc_params->loc_data.loc_by_ref.lapl_id, 
-                                              loc_params->loc_data.loc_by_ref.ref_type, 
-                                              loc_params->loc_data.loc_by_ref._ref)) < 0)
-                    HGOTO_ERROR(H5E_REFERENCE, H5E_CANTOPENOBJ, NULL, "unable to dereference object")
-
-                *opened_type = H5I_get_type(temp_id);
-                if(NULL == (ret_value = H5I_remove(temp_id)))
-                    HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, NULL, "unable to open object")
-                break;
-            }
-
-        case H5VL_OBJECT_BY_SELF:
-        default:
-            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, NULL, "unknown open parameters")
-    } /* end switch */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_object_open() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5VL__native_object_copy
- *
- * Purpose:	Copies an object inside a native h5 file.
- *
- * Return:	Success:	0
- *		Failure:	-1
- *
- * Programmer:  Mohamad Chaarawi
- *              March, 2012
- *
- *-------------------------------------------------------------------------
- */
-static herr_t 
-H5VL__native_object_copy(void *src_obj, const H5VL_loc_params_t *loc_params1, const char *src_name, 
-    void *dst_obj, const H5VL_loc_params_t *loc_params2, const char *dst_name, 
-    hid_t ocpypl_id, hid_t lcpl_id, hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
-{
-    H5G_loc_t	src_loc;                /* Source object group location */
-    H5G_loc_t	dst_loc;                /* Destination group location */
-    herr_t      ret_value = FAIL;
-    
-    FUNC_ENTER_STATIC
-
-    /* get location for objects */
-    if(H5G_loc_real(src_obj, loc_params1->obj_type, &src_loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-    if(H5G_loc_real(dst_obj, loc_params2->obj_type, &dst_loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-    /* Copy the object */
-    if((ret_value = H5O_copy(&src_loc, src_name, &dst_loc, dst_name, ocpypl_id, lcpl_id)) < 0)
-        HGOTO_ERROR(H5E_SYM, H5E_CANTCOPY, FAIL, "unable to copy object")    
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_object_copy() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_object_get
- *
- * Purpose:     Gets certain data about an object
- *
- * Return:      SUCCEED/FAIL
- *
- * Programmer:  Mohamad Chaarawi
- *              March, 2012
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_object_get(void *obj, const H5VL_loc_params_t *loc_params, H5VL_object_get_t get_type, 
-    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
-{
-    herr_t      ret_value = SUCCEED;    /* Return value */
-    H5G_loc_t	loc;                    /* Location of group */
-
-    FUNC_ENTER_STATIC
-
-    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-    switch(get_type) {
-        /* H5Rget_region */
-        case H5VL_REF_GET_REGION:
-            {
-                hid_t       *ret                    =  HDva_arg(arguments, hid_t *);
-                H5R_type_t  H5_ATTR_UNUSED ref_type =  HDva_arg(arguments, H5R_type_t);
-                void        *ref                    =  HDva_arg(arguments, void *);
-                H5S_t       *space = NULL;    /* Dataspace object */
-
-                /* Get the dataspace with the correct region selected */
-                if((space = H5R__get_region(loc.oloc->file, ref)) == NULL)
-                    HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, FAIL, "unable to retrieve region")
-
-                /* Atomize */
-                if((*ret = H5I_register(H5I_DATASPACE, space, TRUE)) < 0)
-                    HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register dataspace atom")
-
-                break;
-            }
-
-        /* H5Rget_obj_type2 */
-        case H5VL_REF_GET_TYPE:
-            {
-                H5O_type_t  *obj_type  =  HDva_arg(arguments, H5O_type_t *);
-                H5R_type_t  ref_type   =  HDva_arg(arguments, H5R_type_t);
-                void        *ref       =  HDva_arg(arguments, void *);
-
-                /* Get the object information */
-                if(H5R__get_obj_type(loc.oloc->file, ref_type, ref, obj_type) < 0)
-                    HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, FAIL, "unable to determine object type")
-                break;
-            }
-
-        /* H5Rget_name */
-        case H5VL_REF_GET_NAME:
-            {
-                ssize_t     *ret       = HDva_arg(arguments, ssize_t *);
-                char        *name      = HDva_arg(arguments, char *);
-                size_t      size       = HDva_arg(arguments, size_t);
-                H5R_type_t  ref_type   = HDva_arg(arguments, H5R_type_t);
-                void        *ref       = HDva_arg(arguments, void *);
-
-                /* Get name */
-                if((*ret = H5R__get_name(loc.oloc->file, ref_type, ref, name, size)) < 0)
-                    HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, FAIL, "unable to determine object path")
-                break;
-            }
-
-        /* H5Iget_name */
-        case H5VL_ID_GET_NAME:
-            {
-                ssize_t *ret = HDva_arg(arguments, ssize_t *);
-                char *name = HDva_arg(arguments, char *);
-                size_t size = HDva_arg(arguments, size_t);
-
-                /* Retrieve object's name */
-                if((*ret = H5G_get_name(&loc, name, size, NULL)) < 0)
-                    HGOTO_ERROR(H5E_ATOM, H5E_CANTGET, FAIL, "can't retrieve object name")
-
-                break;
-            }
-
-        default:
-            HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't get this type of information from object")
-    } /* end switch */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_object_get() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_object_specific
- *
- * Purpose:	Specific operation on an object
- *
- * Return:      SUCCEED/FAIL
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_object_specific(void *obj, const H5VL_loc_params_t *loc_params, H5VL_object_specific_t specific_type, 
-    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
-{
-    H5G_loc_t    loc;
-    herr_t       ret_value = SUCCEED;    /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-    switch(specific_type) {
-        /* H5Oincr_refcount / H5Odecr_refcount */
-        case H5VL_OBJECT_CHANGE_REF_COUNT:
-            {
-                int update_ref  = HDva_arg(arguments, int);
-                H5O_loc_t  *oloc = loc.oloc;
-
-                if(H5O_link(oloc, update_ref) < 0)
-                    HGOTO_ERROR(H5E_OHDR, H5E_LINKCOUNT, FAIL, "modifying object link count failed")
-
-                break;
-            }
-
-        /* H5Oexists_by_name */
-        case H5VL_OBJECT_EXISTS:
-            {
-                htri_t *ret = HDva_arg(arguments, htri_t *);
-
-                if(loc_params->type == H5VL_OBJECT_BY_NAME) {
-                    /* Check if the object exists */
-                    if((*ret = H5G_loc_exists(&loc, loc_params->loc_data.loc_by_name.name)) < 0)
-                        HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "unable to determine if '%s' exists", loc_params->loc_data.loc_by_name.name)
-                } /* end if */
-                else
-                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown object exists parameters")
-                break;
-            }
-
-        case H5VL_OBJECT_VISIT:
-            {
-                H5_index_t idx_type     = HDva_arg(arguments, H5_index_t);
-                H5_iter_order_t order   = HDva_arg(arguments, H5_iter_order_t);
-                H5O_iterate_t op        = HDva_arg(arguments, H5O_iterate_t);
-                void *op_data           = HDva_arg(arguments, void *);
-                unsigned fields         = HDva_arg(arguments, unsigned);
-
-                /* Call internal object visitation routine */
-                if(loc_params->type == H5VL_OBJECT_BY_SELF) {
-                    /* H5Ovisit */
-                    if((ret_value = H5O__visit(&loc, ".", idx_type, order, op, op_data, fields)) < 0)
-                        HGOTO_ERROR(H5E_OHDR, H5E_BADITER, FAIL, "object visitation failed")
-                } /* end if */
-                else if(loc_params->type == H5VL_OBJECT_BY_NAME) {
-                    /* H5Ovisit_by_name */
-                    if((ret_value = H5O__visit(&loc, loc_params->loc_data.loc_by_name.name, idx_type, order, op, op_data, fields)) < 0)
-                        HGOTO_ERROR(H5E_OHDR, H5E_BADITER, FAIL, "object visitation failed")
-                } /* end else-if */
-                else
-                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown object visit params");
-                break;
-            }
-
-        case H5VL_OBJECT_FLUSH:
-            {
-                hid_t   oid     = HDva_arg(arguments, hid_t);
-
-                /* Flush the object's metadata */
-                if(H5O_flush(loc.oloc, oid) < 0)
-                    HGOTO_ERROR(H5E_OHDR, H5E_CANTFLUSH, FAIL, "unable to flush object")
-
-                break;
-            }
-
-        case H5VL_OBJECT_REFRESH:
-            {
-                hid_t                   oid         = HDva_arg(arguments, hid_t);
-                H5O_loc_t              *oloc        = loc.oloc;
-
-                /* Refresh the metadata */
-                if(H5O_refresh_metadata(oid, *oloc) < 0)
-                    HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, FAIL, "unable to refresh object")
-
-                break;
-            }
-
-        case H5VL_REF_CREATE:
-            {
-                void        *ref      = HDva_arg(arguments, void *);
-                const char  *name     = HDva_arg(arguments, char *);
-                H5R_type_t  ref_type  = HDva_arg(arguments, H5R_type_t);
-                hid_t       space_id  = HDva_arg(arguments, hid_t);
-                H5S_t       *space = NULL;   /* Pointer to dataspace containing region */
-                
-                if(space_id != (-1) && (NULL == (space = (H5S_t *)H5I_object_verify(space_id, H5I_DATASPACE))))
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataspace")
-
-                /* Create reference */
-                if(H5R__create(ref, &loc, name, ref_type, space) < 0)
-                    HGOTO_ERROR(H5E_REFERENCE, H5E_CANTCREATE, FAIL, "unable to create reference")
-
-                break;
-            }
-
-        default:
-            HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't recognize this operation type")
-    } /* end switch */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_object_specific() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5VL__native_object_optional
- *
- * Purpose:	Perform a connector-specific operation for an objectibute
- *
- * Return:	Success:	0
- *		Failure:	-1
- *
- * Programmer:  Mohamad Chaarawi
- *              April, 2012
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_object_optional(void *obj, hid_t H5_ATTR_UNUSED dxpl_id,
-    void H5_ATTR_UNUSED **req, va_list arguments)
-{
-    H5VL_native_object_optional_t optional_type = HDva_arg(arguments, H5VL_native_object_optional_t);
-    H5VL_loc_params_t *loc_params = HDva_arg(arguments, H5VL_loc_params_t *);
-    H5G_loc_t	loc;                    /* Location of group */
-    herr_t       ret_value = SUCCEED;    /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-
-    switch(optional_type) {
-        /* H5Oget_info / H5Oget_info_by_name / H5Oget_info_by_idx */
-        case H5VL_NATIVE_OBJECT_GET_INFO:
-            {
-                H5O_info_t  *obj_info = HDva_arg(arguments, H5O_info_t *);
-                unsigned fields         = HDva_arg(arguments, unsigned);
-
-                if(loc_params->type == H5VL_OBJECT_BY_SELF) { /* H5Oget_info */
-                    /* Retrieve the object's information */
-                    if(H5G_loc_info(&loc, ".", obj_info, fields) < 0)
-                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
-                } /* end if */
-                else if(loc_params->type == H5VL_OBJECT_BY_NAME) { /* H5Oget_info_by_name */
-                    /* Retrieve the object's information */
-                    if(H5G_loc_info(&loc, loc_params->loc_data.loc_by_name.name, obj_info, fields) < 0)
-                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
-                } /* end else-if */
-                else if(loc_params->type == H5VL_OBJECT_BY_IDX) { /* H5Oget_info_by_idx */
-                    H5G_loc_t   obj_loc;                /* Location used to open group */
-                    H5G_name_t  obj_path;            	/* Opened object group hier. path */
-                    H5O_loc_t   obj_oloc;            	/* Opened object object location */
-
-                    /* Set up opened group location to fill in */
-                    obj_loc.oloc = &obj_oloc;
-                    obj_loc.path = &obj_path;
-                    H5G_loc_reset(&obj_loc);
-
-                    /* Find the object's location, according to the order in the index */
-                    if(H5G_loc_find_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, 
-                                           loc_params->loc_data.loc_by_idx.idx_type, 
-                                           loc_params->loc_data.loc_by_idx.order, 
-                                           loc_params->loc_data.loc_by_idx.n, &obj_loc/*out*/) < 0)
-                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "group not found")
-
-                    /* Retrieve the object's information */
-                    if(H5O_get_info(obj_loc.oloc, obj_info, fields) < 0) {
-                        H5G_loc_free(&obj_loc);
-                        HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "can't retrieve object info")
-                    } /* end if */
-
-                    /* Release the object location */
-                    if(H5G_loc_free(&obj_loc) < 0)
-                        HGOTO_ERROR(H5E_OHDR, H5E_CANTRELEASE, FAIL, "can't free location")
-                } /* end else-if */
-                else
-                    HGOTO_ERROR(H5E_OHDR, H5E_UNSUPPORTED, FAIL, "unknown get info parameters")
-                break;
-            }
-
-        /* H5Oget_comment / H5Oget_comment_by_name */
-        case H5VL_NATIVE_OBJECT_GET_COMMENT:
-            {
-                char     *comment =  HDva_arg(arguments, char *);
-                size_t   bufsize  =  HDva_arg(arguments, size_t);
-                ssize_t  *ret     =  HDva_arg(arguments, ssize_t *);
-
-                /* Retrieve the object's comment */
-                if(loc_params->type == H5VL_OBJECT_BY_SELF) { /* H5Oget_comment */
-                    if((*ret = H5G_loc_get_comment(&loc, ".", comment/*out*/, bufsize)) < 0)
-                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
-                } /* end if */
-                else if(loc_params->type == H5VL_OBJECT_BY_NAME) { /* H5Oget_comment_by_name */
-                    if((*ret = H5G_loc_get_comment(&loc, loc_params->loc_data.loc_by_name.name, comment/*out*/, bufsize)) < 0)
-                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
-                } /* end else-if */
-                else
-                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown set_coment parameters")
-                break;
-            }
-
-        /* H5Oset_comment */
-        case H5VL_NATIVE_OBJECT_SET_COMMENT:
-            {
-                const char    *comment  = HDva_arg(arguments, char *);
-
-                if(loc_params->type == H5VL_OBJECT_BY_SELF) { /* H5Oset_comment */
-                    /* (Re)set the object's comment */
-                    if(H5G_loc_set_comment(&loc, ".", comment) < 0)
-                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
-                } /* end if */
-                else if(loc_params->type == H5VL_OBJECT_BY_NAME) { /* H5Oset_comment_by_name */
-                    /* (Re)set the object's comment */
-                    if(H5G_loc_set_comment(&loc, loc_params->loc_data.loc_by_name.name, comment) < 0)
-                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
-                } /* end else-if */
-                else
-                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown set_coment parameters")
-                break;
-            }
-
-        default:
-            HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't perform this operation on object");       
-    } /* end switch */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_object_optional() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5VL__native_datatype_commit
- *
- * Purpose:	Commits a datatype inside a native h5 file.
- *
- * Return:	Success:	datatype id. 
- *		Failure:	NULL
- *
- * Programmer:  Mohamad Chaarawi
- *              March, 2012
- *
- *-------------------------------------------------------------------------
- */
-static void *
-H5VL__native_datatype_commit(void *obj, const H5VL_loc_params_t *loc_params, const char *name,
-    hid_t type_id, hid_t lcpl_id, hid_t tcpl_id, hid_t H5_ATTR_UNUSED tapl_id,
-    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
-{
-    H5G_loc_t	loc;                    /* Location to commit datatype */
-    H5T_t	*dt;                    /* Datatype for ID */
-    H5T_t	*type = NULL;           /* copy of the original type which will be committed */
-    void        *ret_value = NULL;      /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    /* check arguments */
-    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file or file object")
-
-    if(NULL == (dt = (H5T_t *)H5I_object_verify(type_id, H5I_DATATYPE)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a datatype")
-
-    /* Check arguments.  We cannot commit an immutable type because H5Tclose()
-     * normally fails on such types (try H5Tclose(H5T_NATIVE_INT)) but closing
-     * a named type should always succeed.
-     */
-    if(H5T_STATE_NAMED == dt->shared->state || H5T_STATE_OPEN == dt->shared->state)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "datatype is already committed")
-    if(H5T_STATE_IMMUTABLE == dt->shared->state)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "datatype is immutable")
-
-    /* Check for a "sensible" datatype to store on disk */
-    if(H5T_is_sensible(dt) <= 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "datatype is not sensible")
-
-    /* Copy the datatype - the copied one will be the type that is
-     * committed, and attached to original datatype above the VOL
-     * layer
-     */
-    if(NULL == (type = H5T_copy(dt, H5T_COPY_TRANSIENT)))
-        HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, NULL, "unable to copy");
-
-    /* Commit the datatype */
-    if(NULL != name) {
-        /* H5Tcommit */
-        if(H5T__commit_named(&loc, name, type, lcpl_id, tcpl_id) < 0)
-            HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, NULL, "unable to commit datatype")
-    } /* end if */
-    else {
-        /* H5Tcommit_anon */
-        if(H5T__commit_anon(loc.oloc->file, type, tcpl_id) < 0)
-            HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, NULL, "unable to commit datatype")
-    } /* end else */
-
-    ret_value = (void *)type;
-
-done:
-    if(NULL == ret_value && type)
-        H5T_close(type);
-
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_datatype_commit() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_datatype_open
- *
- * Purpose:     Opens a named datatype inside a native h5 file.
- *
- * Return:      Success:    datatype pointer
- *              Failure:    NULL
- *
- *-------------------------------------------------------------------------
- */
-static void *
-H5VL__native_datatype_open(void *obj, const H5VL_loc_params_t *loc_params, const char *name, 
-    hid_t H5_ATTR_UNUSED tapl_id, hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
-{
-    H5T_t       *type = NULL;           /* Datatype opened in file */
-    H5G_loc_t    loc;                   /* Group location of object to open */
-    void        *ret_value = NULL;
-
-    FUNC_ENTER_STATIC
-
-    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file or file object")
-
-    /* Open the datatype */
-    if(NULL == (type = H5T__open_name(&loc, name)))
-        HGOTO_ERROR(H5E_DATATYPE, H5E_CANTOPENOBJ, NULL, "unable to open named datatype")
-
-    type->vol_obj = NULL;
-
-    ret_value = (void *)type;
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_datatype_open() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5VL__native_datatype_get
- *
- * Purpose:	Get information about a datatype
- *
- * Return:	Success:	0
- *		Failure:	-1
- *
- * Programmer:  Mohamad Chaarawi
- *              June, 2013
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_datatype_get(void *obj, H5VL_datatype_get_t get_type, 
-    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
-{
-    H5T_t       *dt = (H5T_t *)obj;
-    herr_t       ret_value = SUCCEED;    /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    switch (get_type) {
-        case H5VL_DATATYPE_GET_BINARY:
-            {
-                ssize_t *nalloc = HDva_arg(arguments, ssize_t *);
-                void *buf = HDva_arg(arguments, void *);
-                size_t size = HDva_arg(arguments, size_t);
-
-                if(H5T_encode(dt, (unsigned char *)buf, &size) < 0)
-                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't determine serialized length of datatype")
-
-                *nalloc = (ssize_t) size;
-                break;
-            }
-
-        /* H5Tget_create_plist */
-        case H5VL_DATATYPE_GET_TCPL:
-            {
-                hid_t *ret_id = HDva_arg(arguments, hid_t *);
-
-                if(H5I_INVALID_HID == (*ret_id = H5T__get_create_plist(dt)))
-                    HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, FAIL, "can't get object creation info");
-
-                break;
-            }
-
-        default:
-            HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't get this type of information from datatype")
-    } /* end switch */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_datatype_get() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5VL__native_datatype_specific
- *
- * Purpose:     Specific operations for datatype
- *
- * Return:      SUCCEED/FAIL
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_datatype_specific(void *obj, H5VL_datatype_specific_t specific_type, 
-                             hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
-{
-    H5T_t       *dt = (H5T_t *)obj;
-    herr_t       ret_value = SUCCEED;    /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    switch(specific_type) {
-        case H5VL_DATATYPE_FLUSH:
-            {
-                hid_t type_id = HDva_arg(arguments, hid_t);
-
-                /* To flush metadata and invoke flush callback if there is */
-                if (H5O_flush_common(&dt->oloc, type_id) < 0)
-                    HGOTO_ERROR(H5E_DATATYPE, H5E_CANTFLUSH, FAIL, "unable to flush datatype")
-
-                break;
-            }
-
-        case H5VL_DATATYPE_REFRESH:
-            {
-                hid_t type_id = HDva_arg(arguments, hid_t);
-
-                /* Call private function to refresh datatype object */
-                if ((H5O_refresh_metadata(type_id, dt->oloc)) < 0)
-                    HGOTO_ERROR(H5E_DATATYPE, H5E_CANTLOAD, FAIL, "unable to refresh datatype")
-
-                break;
-            }
-
-        default:
-            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "invalid specific operation")
-    } /* end switch */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_datatype_specific() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5VL__native_datatype_close
- *
- * Purpose:	Closes a datatype.
- *
- * Return:	Success:	0
- *		Failure:	-1, datatype not closed.
- *
- * Programmer:  Mohamad Chaarawi
- *              March, 2012
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5VL__native_datatype_close(void *dt, hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
-{
-    herr_t ret_value = SUCCEED;                 /* Return value */
-
-    FUNC_ENTER_STATIC
-
-    if(H5T_close((H5T_t*)dt) < 0)
-        HGOTO_ERROR(H5E_SYM, H5E_CANTDEC, FAIL, "can't close datatype")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5VL__native_datatype_close() */
-
diff --git a/src/H5VLnative.h b/src/H5VLnative.h
index 8ae3a66..1a3007a 100644
--- a/src/H5VLnative.h
+++ b/src/H5VLnative.h
@@ -25,14 +25,70 @@
 #define H5VL_NATIVE_VALUE       H5_VOL_NATIVE   /* enum value */
 #define H5VL_NATIVE_VERSION     0
 
+/* Typedef and values for native VOL connector attribute optional VOL operations */
+typedef int H5VL_native_attr_optional_t;
+#ifndef H5_NO_DEPRECATED_SYMBOLS
+#define H5VL_NATIVE_ATTR_ITERATE_OLD    0   /* H5Aiterate (deprecated routine) */
+#endif /* H5_NO_DEPRECATED_SYMBOLS */
+
+/* Typedef and values for native VOL connector dataset optional VOL operations */
+typedef int H5VL_native_dataset_optional_t;
+#define H5VL_NATIVE_DATASET_FORMAT_CONVERT          0   /* H5Dformat_convert (internal) */
+#define H5VL_NATIVE_DATASET_GET_CHUNK_INDEX_TYPE    1   /* H5Dget_chunk_index_type      */
+#define H5VL_NATIVE_DATASET_GET_CHUNK_STORAGE_SIZE  2   /* H5Dget_chunk_storage_size    */
+#define H5VL_NATIVE_DATASET_CHUNK_READ              3   /* H5Dchunk_read                */
+#define H5VL_NATIVE_DATASET_CHUNK_WRITE             4   /* H5Dchunk_write               */
+
+/* Typedef and values for native VOL connector file optional VOL operations */
+typedef int H5VL_native_file_optional_t;
+#define H5VL_NATIVE_FILE_CLEAR_ELINK_CACHE              0   /* H5Fclear_elink_file_cache            */
+#define H5VL_NATIVE_FILE_GET_FILE_IMAGE                 1   /* H5Fget_file_image                    */
+#define H5VL_NATIVE_FILE_GET_FREE_SECTIONS              2   /* H5Fget_free_sections                 */
+#define H5VL_NATIVE_FILE_GET_FREE_SPACE                 3   /* H5Fget_freespace                     */
+#define H5VL_NATIVE_FILE_GET_INFO                       4   /* H5Fget_info1/2                       */
+#define H5VL_NATIVE_FILE_GET_MDC_CONF                   5   /* H5Fget_mdc_config                    */
+#define H5VL_NATIVE_FILE_GET_MDC_HR                     6   /* H5Fget_mdc_hit_rate                  */
+#define H5VL_NATIVE_FILE_GET_MDC_SIZE                   7   /* H5Fget_mdc_size                      */
+#define H5VL_NATIVE_FILE_GET_SIZE                       8   /* H5Fget_filesize                      */
+#define H5VL_NATIVE_FILE_GET_VFD_HANDLE                 9   /* H5Fget_vfd_handle                    */
+#define H5VL_NATIVE_FILE_GET_FILE_ID                    10  /* H5Fget_file_id                       */
+#define H5VL_NATIVE_FILE_RESET_MDC_HIT_RATE             11  /* H5Freset_mdc_hit_rate_stats          */
+#define H5VL_NATIVE_FILE_SET_MDC_CONFIG                 12  /* H5Fset_mdc_config                    */
+#define H5VL_NATIVE_FILE_GET_METADATA_READ_RETRY_INFO   13  /* H5Fget_metadata_read_retry_info      */
+#define H5VL_NATIVE_FILE_START_SWMR_WRITE               14  /* H5Fstart_swmr_write                  */
+#define H5VL_NATIVE_FILE_START_MDC_LOGGING              15  /* H5Fstart_mdc_logging                 */
+#define H5VL_NATIVE_FILE_STOP_MDC_LOGGING               16  /* H5Fstop_mdc_logging                  */
+#define H5VL_NATIVE_FILE_GET_MDC_LOGGING_STATUS         17  /* H5Fget_mdc_logging_status            */
+#define H5VL_NATIVE_FILE_FORMAT_CONVERT                 18  /* H5Fformat_convert                    */
+#define H5VL_NATIVE_FILE_RESET_PAGE_BUFFERING_STATS     19  /* H5Freset_page_buffering_stats        */
+#define H5VL_NATIVE_FILE_GET_PAGE_BUFFERING_STATS       20  /* H5Fget_page_buffering_stats          */
+#define H5VL_NATIVE_FILE_GET_MDC_IMAGE_INFO             21  /* H5Fget_mdc_image_info                */
+#define H5VL_NATIVE_FILE_GET_EOA                        22  /* H5Fget_eoa                           */
+#define H5VL_NATIVE_FILE_INCR_FILESIZE                  23  /* H5Fincrement_filesize                */
+#define H5VL_NATIVE_FILE_SET_LIBVER_BOUNDS              24  /* H5Fset_latest_format/libver_bounds   */
+#define H5VL_NATIVE_FILE_GET_MIN_DSET_OHDR_FLAG         25  /* H5Fget_dset_no_attrs_hint            */
+#define H5VL_NATIVE_FILE_SET_MIN_DSET_OHDR_FLAG         26  /* H5Fset_dset_no_attrs_hint            */
+
+/* Typedef and values for native VOL connector group optional VOL operations */
+typedef int H5VL_native_group_optional_t;
+#ifndef H5_NO_DEPRECATED_SYMBOLS
+#define H5VL_NATIVE_GROUP_ITERATE_OLD   0   /* HG5Giterate (deprecated routine) */
+#define H5VL_NATIVE_GROUP_GET_OBJINFO   1   /* HG5Gget_objinfo (deprecated routine) */
+#endif /* H5_NO_DEPRECATED_SYMBOLS */
+
+/* Typedef and values for native VOL connector object optional VOL operations */
+typedef int H5VL_native_object_optional_t;
+#define H5VL_NATIVE_OBJECT_GET_COMMENT      0   /* H5G|H5Oget_comment, H5Oget_comment_by_name   */
+#define H5VL_NATIVE_OBJECT_GET_INFO         1   /* H5Oget_info(_by_idx, _by_name)(2)            */
+#define H5VL_NATIVE_OBJECT_SET_COMMENT      2   /* H5G|H5Oset_comment, H5Oset_comment_by_name   */
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+/* Private functions */
 H5_DLL hid_t H5VL_native_register(void);
 
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/H5VLnative_attr.c b/src/H5VLnative_attr.c
new file mode 100644
index 0000000..7d9f0ac
--- /dev/null
+++ b/src/H5VLnative_attr.c
@@ -0,0 +1,597 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*
+ * Purpose:     Attribute callbacks for the native VOL connector
+ *
+ */
+
+#define H5A_FRIEND              /* Suppress error about including H5Apkg    */
+
+#include "H5private.h"          /* Generic Functions                        */
+#include "H5Apkg.h"             /* Attributes                               */
+#include "H5Eprivate.h"         /* Error handling                           */
+#include "H5Fprivate.h"         /* Files                                    */
+#include "H5Gprivate.h"         /* Groups                                   */
+#include "H5Iprivate.h"         /* IDs                                      */
+#include "H5Pprivate.h"         /* Property lists                           */
+#include "H5Sprivate.h"         /* Dataspaces                               */
+#include "H5Tprivate.h"         /* Datatypes                                */
+#include "H5VLprivate.h"        /* Virtual Object Layer                     */
+
+#include "H5VLnative_private.h" /* Native VOL connector                     */
+
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_attr_create
+ *
+ * Purpose:     Handles the attribute create callback
+ *
+ * Return:      Success:    attribute pointer
+ *              Failure:    NULL
+ *
+ *-------------------------------------------------------------------------
+ */
+void *
+H5VL__native_attr_create(void *obj, const H5VL_loc_params_t *loc_params, const char *attr_name,
+    hid_t acpl_id, hid_t H5_ATTR_UNUSED aapl_id, hid_t H5_ATTR_UNUSED dxpl_id,
+    void H5_ATTR_UNUSED **req)
+{
+    H5G_loc_t       loc;                /* Object location */
+    H5G_loc_t       obj_loc;            /* Location used to open group */
+    hbool_t         loc_found = FALSE;  
+    H5P_genplist_t  *plist;             /* Property list pointer */
+    hid_t           type_id, space_id;
+    H5T_t           *type, *dt;         /* Datatype to use for attribute */
+    H5S_t           *space;             /* Dataspace to use for attribute */
+    H5A_t           *attr = NULL;
+    void            *ret_value = NULL;
+
+    FUNC_ENTER_PACKAGE
+
+    /* Get the plist structure */
+    if(NULL == (plist = (H5P_genplist_t *)H5I_object(acpl_id)))
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, NULL, "can't find object for ID")
+
+    /* get creation properties */
+    if(H5P_get(plist, H5VL_PROP_ATTR_TYPE_ID, &type_id) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get property value for datatype id")
+    if(H5P_get(plist, H5VL_PROP_ATTR_SPACE_ID, &space_id) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get property value for space id")
+
+    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file or file object")
+    if(0 == (H5F_INTENT(loc.oloc->file) & H5F_ACC_RDWR))
+        HGOTO_ERROR(H5E_ARGS, H5E_WRITEERROR, NULL, "no write intent on file")
+
+    if(NULL == (dt = (H5T_t *)H5I_object_verify(type_id, H5I_DATATYPE)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a datatype")
+    /* If this is a named datatype, get the connector's pointer to the datatype */
+    type = H5T_get_actual_type(dt);
+
+    if(NULL == (space = (H5S_t *)H5I_object_verify(space_id, H5I_DATASPACE)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a data space")
+
+    if(loc_params->type == H5VL_OBJECT_BY_SELF) {
+        /* H5Acreate */
+        /* Go do the real work for attaching the attribute to the dataset */
+        if(NULL == (attr = H5A__create(&loc, attr_name, type, space, acpl_id)))
+            HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, NULL, "unable to create attribute")
+    } /* end if */
+    else if(loc_params->type == H5VL_OBJECT_BY_NAME) {
+        /* H5Acreate_by_name */
+        if(NULL == (attr = H5A__create_by_name(&loc, loc_params->loc_data.loc_by_name.name, attr_name, type, space, acpl_id)))
+            HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, NULL, "unable to create attribute")
+    } /* end else-if */
+    else
+        HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, NULL, "unknown attribute create parameters")
+
+    ret_value = (void *)attr;
+
+done:
+    /* Release resources */
+    if(loc_found && H5G_loc_free(&obj_loc) < 0)
+        HDONE_ERROR(H5E_ATTR, H5E_CANTRELEASE, NULL, "can't free location") 
+
+   FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_attr_create() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_attr_open
+ *
+ * Purpose:     Handles the attribute open callback
+ *
+ * Return:      Success:    attribute pointer
+ *              Failure:    NULL
+ *
+ *-------------------------------------------------------------------------
+ */
+void *
+H5VL__native_attr_open(void *obj, const H5VL_loc_params_t *loc_params, const char *attr_name, 
+    hid_t H5_ATTR_UNUSED aapl_id, hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
+{
+    H5G_loc_t    loc;             /* Object location */
+    H5A_t        *attr = NULL;    /* Attribute opened */
+    void         *ret_value;
+
+    FUNC_ENTER_PACKAGE
+
+    /* check arguments */
+    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file or file object")
+
+    if(loc_params->type == H5VL_OBJECT_BY_SELF) {
+        /* H5Aopen */
+        /* Open the attribute */
+        if(NULL == (attr = H5A__open(&loc, attr_name)))
+            HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, NULL, "unable to open attribute: '%s'", attr_name)
+    } /* end if */
+    else if(loc_params->type == H5VL_OBJECT_BY_NAME) {
+        /* H5Aopen_by_name */
+        /* Open the attribute on the object header */
+        if(NULL == (attr = H5A__open_by_name(&loc, loc_params->loc_data.loc_by_name.name, attr_name)))
+            HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, NULL, "can't open attribute")
+    } /* end else-if */
+    else if(loc_params->type == H5VL_OBJECT_BY_IDX) {
+        /* H5Aopen_by_idx */
+        /* Open the attribute in the object header */
+        if(NULL == (attr = H5A__open_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, 
+                                           loc_params->loc_data.loc_by_idx.idx_type, 
+                                           loc_params->loc_data.loc_by_idx.order, 
+                                           loc_params->loc_data.loc_by_idx.n)))
+            HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, NULL, "unable to open attribute")
+    } /* end else-if */
+    else
+        HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, NULL, "unknown attribute open parameters")
+
+    ret_value = (void *)attr;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_attr_open() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_attr_read
+ *
+ * Purpose:     Handles the attribute read callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_attr_read(void *attr, hid_t dtype_id, void *buf,
+    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
+{
+    H5T_t *mem_type;            /* Memory datatype */
+    herr_t ret_value;           /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    if(NULL == (mem_type = (H5T_t *)H5I_object_verify(dtype_id, H5I_DATATYPE)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a datatype")
+
+    /* Go write the actual data to the attribute */
+    if((ret_value = H5A__read((H5A_t*)attr, mem_type, buf)) < 0)
+        HGOTO_ERROR(H5E_ATTR, H5E_READERROR, FAIL, "unable to read attribute")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_attr_read() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_attr_write
+ *
+ * Purpose:     Handles the attribute write callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_attr_write(void *attr, hid_t dtype_id, const void *buf,
+    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
+{
+    H5T_t *mem_type;            /* Memory datatype */
+    herr_t ret_value;           /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    if(NULL == (mem_type = (H5T_t *)H5I_object_verify(dtype_id, H5I_DATATYPE)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a datatype")
+
+    /* Go write the actual data to the attribute */
+    if((ret_value = H5A__write((H5A_t*)attr, mem_type, buf)) < 0)
+        HGOTO_ERROR(H5E_ATTR, H5E_WRITEERROR, FAIL, "unable to write attribute")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_attr_write() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_attr_get
+ *
+ * Purpose:     Handles the attribute get callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_attr_get(void *obj, H5VL_attr_get_t get_type,
+    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
+{
+    herr_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    switch(get_type) {
+        /* H5Aget_space */
+        case H5VL_ATTR_GET_SPACE:
+            {
+                hid_t   *ret_id = HDva_arg(arguments, hid_t *);
+                H5A_t   *attr = (H5A_t *)obj;
+
+                if((*ret_id = H5A_get_space(attr)) < 0)
+                    HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get space ID of attribute")
+                break;
+            }
+
+        /* H5Aget_type */
+        case H5VL_ATTR_GET_TYPE:
+            {
+                hid_t   *ret_id = HDva_arg(arguments, hid_t *);
+                H5A_t   *attr = (H5A_t *)obj;
+
+                if((*ret_id = H5A__get_type(attr)) < 0)
+                    HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get datatype ID of attribute")
+                break;
+            }
+
+        /* H5Aget_create_plist */
+        case H5VL_ATTR_GET_ACPL:
+            {
+                hid_t   *ret_id = HDva_arg(arguments, hid_t *);
+                H5A_t   *attr = (H5A_t *)obj;
+
+                if((*ret_id = H5A__get_create_plist(attr)) < 0)
+                    HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get creation property list for attr")
+
+                break;
+            }
+
+        /* H5Aget_name */
+        case H5VL_ATTR_GET_NAME:
+            {
+                const H5VL_loc_params_t *loc_params = HDva_arg(arguments, const H5VL_loc_params_t *);
+                size_t  buf_size = HDva_arg(arguments, size_t);
+                char    *buf = HDva_arg(arguments, char *);
+                ssize_t *ret_val = HDva_arg(arguments, ssize_t *);
+                H5A_t   *attr = NULL;
+
+                if(H5VL_OBJECT_BY_SELF == loc_params->type) {
+                    attr = (H5A_t *)obj;
+                    /* Call private function in turn */
+                    if(0 > (*ret_val = H5A__get_name(attr, buf_size, buf)))
+                        HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "can't get attribute name")
+                }
+                else if(H5VL_OBJECT_BY_IDX == loc_params->type) {
+                    H5G_loc_t loc;
+                    
+                    /* check arguments */
+                    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
+                        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+                    /* Open the attribute on the object header */
+                    if(NULL == (attr = H5A__open_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, 
+                                                       loc_params->loc_data.loc_by_idx.idx_type, 
+                                                       loc_params->loc_data.loc_by_idx.order, 
+                                                       loc_params->loc_data.loc_by_idx.n)))
+                        HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "can't open attribute")
+
+                    /* Get the length of the name */
+                    *ret_val = (ssize_t)HDstrlen(attr->shared->name);
+
+                    /* Copy the name into the user's buffer, if given */
+                    if(buf) {
+                        HDstrncpy(buf, attr->shared->name, MIN((size_t)(*ret_val + 1), buf_size));
+                        if((size_t)(*ret_val) >= buf_size)
+                            buf[buf_size - 1]='\0';
+                    } /* end if */
+
+                    /* Release resources */
+                    if(attr && H5A__close(attr) < 0)
+                        HGOTO_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
+                }
+                else
+                    HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't get name of attr")
+
+                break;
+            }
+
+        /* H5Aget_info */
+        case H5VL_ATTR_GET_INFO:
+            {
+                const H5VL_loc_params_t *loc_params = HDva_arg(arguments, const H5VL_loc_params_t *);
+                H5A_info_t   *ainfo = HDva_arg(arguments, H5A_info_t *);
+                H5A_t   *attr = NULL;
+
+                if(H5VL_OBJECT_BY_SELF == loc_params->type) {
+                    attr = (H5A_t *)obj;
+                    if(H5A__get_info(attr, ainfo) < 0)
+                        HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get attribute info")
+                }
+                else if(H5VL_OBJECT_BY_NAME == loc_params->type) {
+                    char *attr_name = HDva_arg(arguments, char *);
+                    H5G_loc_t loc;
+                    
+                    /* check arguments */
+                    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
+                        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+                    /* Open the attribute on the object header */
+                    if(NULL == (attr = H5A__open_by_name(&loc, loc_params->loc_data.loc_by_name.name, attr_name)))
+                        HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "can't open attribute")
+
+                    /* Get the attribute information */
+                    if(H5A__get_info(attr, ainfo) < 0)
+                        HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "unable to get attribute info")
+
+                    /* Release resources */
+                    if(attr && H5A__close(attr) < 0)
+                        HGOTO_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
+                }
+                else if(H5VL_OBJECT_BY_IDX == loc_params->type) {
+                    H5G_loc_t loc;
+                    
+                    /* check arguments */
+                    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
+                        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+                    /* Open the attribute on the object header */
+                    if(NULL == (attr = H5A__open_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, 
+                                                       loc_params->loc_data.loc_by_idx.idx_type, 
+                                                       loc_params->loc_data.loc_by_idx.order, 
+                                                       loc_params->loc_data.loc_by_idx.n)))
+                        HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "can't open attribute")
+
+                    /* Get the attribute information */
+                    if(H5A__get_info(attr, ainfo) < 0)
+                        HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "unable to get attribute info")
+
+                    /* Release resources */
+                    if(attr && H5A__close(attr) < 0)
+                        HGOTO_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
+                }
+                else
+                    HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't get name of attr")
+
+                break;
+            }
+
+        case H5VL_ATTR_GET_STORAGE_SIZE:
+            {
+                hsize_t *ret = HDva_arg(arguments, hsize_t *);
+                H5A_t   *attr = (H5A_t *)obj;
+
+                /* Set return value */
+                *ret = attr->shared->data_size;
+                break;
+            }
+
+        default:
+            HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't get this type of information from attr")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_attr_get() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_attr_specific
+ *
+ * Purpose:     Handles the attribute specific callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_attr_specific(void *obj, const H5VL_loc_params_t *loc_params, H5VL_attr_specific_t specific_type, 
+    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
+{
+    H5G_loc_t   loc;
+    herr_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    /* Get location for passed-in object */
+    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+    switch(specific_type) {
+        case H5VL_ATTR_DELETE:
+            {
+                char    *attr_name = HDva_arg(arguments, char *);
+
+                if(H5VL_OBJECT_BY_SELF == loc_params->type) {
+                    /* H5Adelete */
+                    /* Delete the attribute from the location */
+                    if(H5O__attr_remove(loc.oloc, attr_name) < 0)
+                        HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute")
+                } /* end if */
+                else if(H5VL_OBJECT_BY_NAME == loc_params->type) {
+                    /* H5Adelete_by_name */
+                    /* Delete the attribute */
+                    if(H5A__delete_by_name(&loc, loc_params->loc_data.loc_by_name.name, attr_name) < 0)
+                        HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute")
+                } /* end else-if */
+                else if(H5VL_OBJECT_BY_IDX == loc_params->type) {
+                    /* H5Adelete_by_idx */
+                    /* Delete the attribute from the location */
+                    if(H5A__delete_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, loc_params->loc_data.loc_by_idx.idx_type,
+                            loc_params->loc_data.loc_by_idx.order, loc_params->loc_data.loc_by_idx.n) < 0)
+                        HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute")
+                } /* end else-if */
+                else
+                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown attribute remove parameters")
+                break;
+            }
+
+        case H5VL_ATTR_EXISTS:
+            {
+                const char *attr_name = HDva_arg(arguments, const char *);
+                htri_t  *ret = HDva_arg(arguments, htri_t *);
+
+                if(loc_params->type == H5VL_OBJECT_BY_SELF) { /* H5Aexists */
+                    /* Check if the attribute exists */
+                    if((*ret = H5O__attr_exists(loc.oloc, attr_name)) < 0)
+                        HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "unable to determine if attribute exists")
+                } /* end if */
+                else if(loc_params->type == H5VL_OBJECT_BY_NAME) { /* H5Aexists_by_name */
+                    /* Check if the attribute exists */
+                    if((*ret = H5A__exists_by_name(loc, loc_params->loc_data.loc_by_name.name, attr_name)) < 0)
+                        HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "unable to determine if attribute exists")
+                } /* end else-if */
+                else
+                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown parameters")
+                break;
+            }
+
+        case H5VL_ATTR_ITER:
+            {
+                H5_index_t          idx_type    = (H5_index_t)HDva_arg(arguments, int); /* enum work-around */
+                H5_iter_order_t     order       = (H5_iter_order_t)HDva_arg(arguments, int); /* enum work-around */
+                hsize_t            *idx         = HDva_arg(arguments, hsize_t *);
+                H5A_operator2_t     op          = HDva_arg(arguments, H5A_operator2_t);
+                void               *op_data     = HDva_arg(arguments, void *);
+
+                if(loc_params->type == H5VL_OBJECT_BY_SELF) { /* H5Aiterate2 */
+                    /* Iterate over attributes */
+                    if((ret_value = H5A__iterate(&loc, ".", idx_type, order, idx, op, op_data)) < 0)
+                        HGOTO_ERROR(H5E_ATTR, H5E_BADITER, FAIL, "error iterating over attributes")
+                } /* end if */
+                else if(loc_params->type == H5VL_OBJECT_BY_NAME) { /* H5Aiterate_by_name */
+                    /* Iterate over attributes by name */
+                    if((ret_value = H5A__iterate(&loc, loc_params->loc_data.loc_by_name.name, idx_type, order, idx, op, op_data)) < 0)
+                        HGOTO_ERROR(H5E_ATTR, H5E_BADITER, FAIL, "attribute iteration failed");
+                } /* end else-if */
+                else
+                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown parameters")
+                break;
+            }
+
+        /* H5Arename/rename_by_name */
+        case H5VL_ATTR_RENAME:
+            {
+                const char *old_name  = HDva_arg(arguments, const char *);
+                const char *new_name  = HDva_arg(arguments, const char *);
+
+                if(loc_params->type == H5VL_OBJECT_BY_SELF) { /* H5Arename */
+                    /* Call attribute rename routine */
+                    if(H5O__attr_rename(loc.oloc, old_name, new_name) < 0)
+                        HGOTO_ERROR(H5E_ATTR, H5E_CANTRENAME, FAIL, "can't rename attribute")
+                } /* end if */
+                else if(loc_params->type == H5VL_OBJECT_BY_NAME) { /* H5Arename_by_name */
+                    /* Call attribute rename routine */
+                    if(H5A__rename_by_name(loc, loc_params->loc_data.loc_by_name.name, old_name, new_name) < 0)
+                        HGOTO_ERROR(H5E_ATTR, H5E_CANTRENAME, FAIL, "can't rename attribute")
+                } /* end else-if */
+                else
+                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown attribute rename parameters")
+                break;
+            }
+
+        default:
+            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "invalid specific operation")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_attr_specific() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_attr_optional
+ *
+ * Purpose:     Handles the attribute optional callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_attr_optional(void H5_ATTR_UNUSED *obj, hid_t H5_ATTR_UNUSED dxpl_id,
+    void H5_ATTR_UNUSED **req, va_list arguments)
+{
+    H5VL_native_attr_optional_t optional_type;
+    herr_t ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    optional_type = HDva_arg(arguments, H5VL_native_attr_optional_t);
+    switch(optional_type) {
+#ifndef H5_NO_DEPRECATED_SYMBOLS
+        case H5VL_NATIVE_ATTR_ITERATE_OLD:
+            {
+                hid_t loc_id = HDva_arg(arguments, hid_t);
+                unsigned *attr_num = HDva_arg(arguments, unsigned *);
+                H5A_operator1_t op = HDva_arg(arguments, H5A_operator1_t);
+                void *op_data = HDva_arg(arguments, void *);
+
+                /* Call the actual iteration routine */
+                if((ret_value = H5A__iterate_old(loc_id, attr_num, op, op_data)) < 0)
+                    HERROR(H5E_VOL, H5E_BADITER, "error iterating over attributes");
+
+                break;
+            }
+#endif /* H5_NO_DEPRECATED_SYMBOLS */
+
+        default:
+            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "invalid optional operation")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_attr_optional() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_attr_close
+ *
+ * Purpose:     Handles the attribute close callback
+ *
+ * Return:      Success:    SUCCEED
+ *              Failure:    FAIL (attribute will not be closed)
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_attr_close(void *attr, hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
+{
+    herr_t ret_value = SUCCEED;                 /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    if(H5A__close((H5A_t*)attr) < 0)
+        HGOTO_ERROR(H5E_SYM, H5E_CANTDEC, FAIL, "can't close attribute")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_attr_close() */
+
diff --git a/src/H5VLnative_dataset.c b/src/H5VLnative_dataset.c
new file mode 100644
index 0000000..8f7351c
--- /dev/null
+++ b/src/H5VLnative_dataset.c
@@ -0,0 +1,575 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*
+ * Purpose:     Dataset callbacks for the native VOL connector
+ *
+ */
+
+#define H5D_FRIEND              /* Suppress error about including H5Dpkg    */
+
+#include "H5private.h"          /* Generic Functions                        */
+#include "H5Dpkg.h"             /* Datasets                                 */
+#include "H5Eprivate.h"         /* Error handling                           */
+#include "H5Fprivate.h"         /* Files                                    */
+#include "H5Gprivate.h"         /* Groups                                   */
+#include "H5Iprivate.h"         /* IDs                                      */
+#include "H5Pprivate.h"         /* Property lists                           */
+#include "H5Sprivate.h"         /* Dataspaces                               */
+#include "H5VLprivate.h"        /* Virtual Object Layer                     */
+
+#include "H5VLnative_private.h" /* Native VOL connector                     */
+
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_dataset_create
+ *
+ * Purpose:     Handles the dataset create callback
+ *
+ * Return:      Success:    dataset pointer
+ *              Failure:    NULL
+ *
+ *-------------------------------------------------------------------------
+ */
+void *
+H5VL__native_dataset_create(void *obj, const H5VL_loc_params_t *loc_params,
+    const char *name, hid_t dcpl_id, hid_t dapl_id, hid_t H5_ATTR_UNUSED dxpl_id,
+    void H5_ATTR_UNUSED **req)
+{
+    H5P_genplist_t *plist;              /* Property list pointer */
+    H5G_loc_t       loc;                 /* Object location to insert dataset into */
+    hid_t           type_id = H5I_INVALID_HID;
+    hid_t           space_id = H5I_INVALID_HID;
+    hid_t           lcpl_id = H5I_INVALID_HID;
+    H5D_t          *dset = NULL;        /* New dataset's info */
+    const H5S_t    *space;              /* Dataspace for dataset */
+    void           *ret_value;
+
+    FUNC_ENTER_PACKAGE
+
+    /* Get the plist structure */
+    if(NULL == (plist = (H5P_genplist_t *)H5I_object(dcpl_id)))
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, NULL, "can't find object for ID")
+
+    /* Get creation properties */
+    if(H5P_get(plist, H5VL_PROP_DSET_TYPE_ID, &type_id) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get property value for datatype id")
+    if(H5P_get(plist, H5VL_PROP_DSET_SPACE_ID, &space_id) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get property value for space id")
+    if(H5P_get(plist, H5VL_PROP_DSET_LCPL_ID, &lcpl_id) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get property value for lcpl id")
+
+    /* Check arguments */
+    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file or file object")
+    if(H5I_DATATYPE != H5I_get_type(type_id))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a datatype ID")
+    if(NULL == (space = (const H5S_t *)H5I_object_verify(space_id, H5I_DATASPACE)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a dataspace ID")
+
+    /* H5Dcreate_anon */
+    if(NULL == name) {
+        /* build and open the new dataset */
+        if(NULL == (dset = H5D__create(loc.oloc->file, type_id, space, dcpl_id, dapl_id)))
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "unable to create dataset")
+    } /* end if */
+    /* H5Dcreate2 */
+    else {
+        /* Create the new dataset & get its ID */
+        if(NULL == (dset = H5D__create_named(&loc, name, type_id, space, lcpl_id, dcpl_id, dapl_id)))
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "unable to create dataset")
+    } /* end else */
+
+    ret_value = (void *)dset;
+
+done:
+    if(NULL == name) {
+        /* Release the dataset's object header, if it was created */
+        if(dset) {
+            H5O_loc_t *oloc;         /* Object location for dataset */
+
+            /* Get the new dataset's object location */
+            if(NULL == (oloc = H5D_oloc(dset)))
+                HDONE_ERROR(H5E_DATASET, H5E_CANTGET, NULL, "unable to get object location of dataset")
+
+            /* Decrement refcount on dataset's object header in memory */
+            if(H5O_dec_rc_by_loc(oloc) < 0)
+                HDONE_ERROR(H5E_DATASET, H5E_CANTDEC, NULL, "unable to decrement refcount on newly created object")
+        } /* end if */
+    } /* end if */
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_dataset_create() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_dataset_open
+ *
+ * Purpose:     Handles the dataset open callback
+ *
+ * Return:      Success:    dataset pointer
+ *              Failure:    NULL
+ *
+ *-------------------------------------------------------------------------
+ */
+void *
+H5VL__native_dataset_open(void *obj, const H5VL_loc_params_t *loc_params, const char *name, 
+    hid_t dapl_id, hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
+{
+    H5D_t       *dset = NULL;
+    H5G_loc_t   loc;                /* Object location of group */
+    void         *ret_value = NULL;
+
+    FUNC_ENTER_PACKAGE
+
+    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file or file object")
+
+    /* Open the dataset */
+    if(NULL == (dset = H5D__open_name(&loc, name, dapl_id)))
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTOPENOBJ, NULL, "unable to open dataset")
+
+    ret_value = (void *)dset;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_dataset_open() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_dataset_read
+ *
+ * Purpose:     Handles the dataset read callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_dataset_read(void *obj, hid_t mem_type_id, hid_t mem_space_id,
+    hid_t file_space_id, hid_t H5_ATTR_UNUSED dxpl_id, void *buf,
+    void H5_ATTR_UNUSED **req)
+{
+    H5D_t         *dset = (H5D_t *)obj;
+    const H5S_t   *mem_space = NULL;
+    const H5S_t   *file_space = NULL;
+    herr_t         ret_value = SUCCEED;                 /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    /* Check arguments */
+    if(NULL == dset->oloc.file)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "dataset is not associated with a file")
+
+    /* Get validated dataspace pointers */
+    if(H5S_get_validated_dataspace(mem_space_id, &mem_space) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "could not get a validated dataspace from mem_space_id")
+    if(H5S_get_validated_dataspace(file_space_id, &file_space) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "could not get a validated dataspace from file_space_id")
+
+    /* Read raw data */
+    if(H5D__read(dset, mem_type_id, mem_space, file_space, buf/*out*/) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL, "can't read data")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_dataset_read() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_dataset_write
+ *
+ * Purpose:     Handles the dataset write callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_dataset_write(void *obj, hid_t mem_type_id, hid_t mem_space_id,
+    hid_t file_space_id, hid_t H5_ATTR_UNUSED dxpl_id, const void *buf,
+    void H5_ATTR_UNUSED **req)
+{
+    H5D_t           *dset = (H5D_t *)obj;
+    const H5S_t     *mem_space = NULL;
+    const H5S_t     *file_space = NULL;
+    herr_t           ret_value = SUCCEED;        /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    /* check arguments */
+    if(NULL == dset->oloc.file)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "dataset is not associated with a file")
+
+    /* Get validated dataspace pointers */
+    if(H5S_get_validated_dataspace(mem_space_id, &mem_space) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "could not get a validated dataspace from mem_space_id")
+    if(H5S_get_validated_dataspace(file_space_id, &file_space) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "could not get a validated dataspace from file_space_id")
+
+    /* Write the data */
+    if(H5D__write(dset, mem_type_id, mem_space, file_space, buf) < 0) 
+        HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "can't write data")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_dataset_write() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_dataset_get
+ *
+ * Purpose:     Handles the dataset get callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_dataset_get(void *obj, H5VL_dataset_get_t get_type,
+    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
+{
+    H5D_t       *dset = (H5D_t *)obj;
+    herr_t       ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    switch(get_type) {
+        /* H5Dget_space */
+        case H5VL_DATASET_GET_SPACE:
+            {
+                hid_t   *ret_id = HDva_arg(arguments, hid_t *);
+
+                if((*ret_id = H5D__get_space(dset)) < 0)
+                    HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get space ID of dataset")
+
+                break;
+            }
+
+        /* H5Dget_space_statuc */
+        case H5VL_DATASET_GET_SPACE_STATUS:
+            {
+                H5D_space_status_t *allocation = HDva_arg(arguments, H5D_space_status_t *);
+
+                /* Read data space address and return */
+                if(H5D__get_space_status(dset, allocation) < 0)
+                    HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to get space status")
+
+                break;
+            }
+
+        /* H5Dget_type */
+        case H5VL_DATASET_GET_TYPE:
+            {
+                hid_t   *ret_id = HDva_arg(arguments, hid_t *);
+
+                if((*ret_id = H5D__get_type(dset)) < 0)
+                    HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get datatype ID of dataset")
+
+                break;
+            }
+
+        /* H5Dget_create_plist */
+        case H5VL_DATASET_GET_DCPL:
+            {
+                hid_t   *ret_id = HDva_arg(arguments, hid_t *);
+
+                if((*ret_id = H5D_get_create_plist(dset)) < 0)
+                    HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get creation property list for dataset")
+
+                break;
+            }
+
+        /* H5Dget_access_plist */
+        case H5VL_DATASET_GET_DAPL:
+            {
+                hid_t   *ret_id = HDva_arg(arguments, hid_t *);
+
+                if((*ret_id = H5D_get_access_plist(dset)) < 0)
+                    HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get access property list for dataset")
+
+                break;
+            }
+
+        /* H5Dget_storage_size */
+        case H5VL_DATASET_GET_STORAGE_SIZE:
+            {
+                hsize_t *ret = HDva_arg(arguments, hsize_t *);
+
+                /* Set return value */
+                if(H5D__get_storage_size(dset, ret) < 0)
+                    HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't get size of dataset's storage")
+                break;
+            }
+
+        /* H5Dget_offset */
+        case H5VL_DATASET_GET_OFFSET:
+            {
+                haddr_t *ret = HDva_arg(arguments, haddr_t *);
+
+                /* Set return value */
+                *ret = H5D__get_offset(dset);
+                if(!H5F_addr_defined(*ret))
+                    *ret = HADDR_UNDEF;
+                break;
+            }
+
+        default:
+            HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't get this type of information from dataset")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_dataset_get() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_dataset_specific
+ *
+ * Purpose:     Handles the dataset specific callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_dataset_specific(void *obj, H5VL_dataset_specific_t specific_type, 
+    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
+{
+    H5D_t       *dset = (H5D_t *)obj;
+    herr_t       ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    switch(specific_type) {
+        /* H5Dspecific_space */
+        case H5VL_DATASET_SET_EXTENT:
+            {
+                const hsize_t *size = HDva_arg(arguments, const hsize_t *); 
+
+                if(H5D__set_extent(dset, size) < 0)
+                    HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to set extent of dataset")
+                break;
+            }
+
+        case H5VL_DATASET_FLUSH:
+            {
+                hid_t dset_id = HDva_arg(arguments, hid_t);
+
+                /* Flush the dataset */
+                if(H5D__flush(dset, dset_id) < 0)
+                    HGOTO_ERROR(H5E_DATASET, H5E_CANTFLUSH, FAIL, "unable to flush dataset")
+
+                break;
+            }
+
+        case H5VL_DATASET_REFRESH:
+            {
+                hid_t dset_id = HDva_arg(arguments, hid_t);
+
+                /* Refresh the dataset */
+                if((H5D__refresh(dset_id, dset)) < 0)
+                    HGOTO_ERROR(H5E_DATASET, H5E_CANTLOAD, FAIL, "unable to refresh dataset")
+
+                break;
+            }
+
+        default:
+            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "invalid specific operation")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_dataset_specific() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_dataset_optional
+ *
+ * Purpose:     Handles the dataset optional callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_dataset_optional(void *obj, hid_t H5_ATTR_UNUSED dxpl_id,
+    void H5_ATTR_UNUSED **req, va_list arguments)
+{
+    H5D_t *dset = NULL;             /* Dataset */
+    H5VL_native_dataset_optional_t optional_type = HDva_arg(arguments, H5VL_native_dataset_optional_t);
+    herr_t ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    switch(optional_type) {
+        case H5VL_NATIVE_DATASET_FORMAT_CONVERT:
+            {
+                dset = (H5D_t *)obj;
+
+                switch(dset->shared->layout.type) {
+                    case H5D_CHUNKED:
+                        /* Convert the chunk indexing type to version 1 B-tree if not */
+                        if(dset->shared->layout.u.chunk.idx_type != H5D_CHUNK_IDX_BTREE)
+                            if((H5D__format_convert(dset)) < 0)
+                                HGOTO_ERROR(H5E_DATASET, H5E_CANTLOAD, FAIL, "unable to downgrade chunk indexing type for dataset")
+                        break;
+
+                    case H5D_CONTIGUOUS:
+                    case H5D_COMPACT:
+                        /* Downgrade the layout version to 3 if greater than 3 */
+                        if(dset->shared->layout.version > H5O_LAYOUT_VERSION_DEFAULT)
+                            if((H5D__format_convert(dset)) < 0)
+                                HGOTO_ERROR(H5E_DATASET, H5E_CANTLOAD, FAIL, "unable to downgrade layout version for dataset")
+                        break;
+
+                    case H5D_VIRTUAL:
+                        /* Nothing to do even though layout is version 4 */
+                        break;
+
+                    case H5D_LAYOUT_ERROR:
+                    case H5D_NLAYOUTS:
+                        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid dataset layout type")
+
+                    default: 
+                        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "unknown dataset layout type")
+                } /* end switch */
+
+                break;
+            }
+
+        case H5VL_NATIVE_DATASET_GET_CHUNK_INDEX_TYPE:
+            {
+                H5D_chunk_index_t *idx_type = HDva_arg(arguments, H5D_chunk_index_t *);
+
+                dset = (H5D_t *)obj;
+
+                /* Make sure the dataset is chunked */
+                if(H5D_CHUNKED != dset->shared->layout.type)
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a chunked dataset")
+
+                /* Get the chunk indexing type */
+                *idx_type = dset->shared->layout.u.chunk.idx_type;
+
+                break;
+            }
+
+        case H5VL_NATIVE_DATASET_GET_CHUNK_STORAGE_SIZE:
+            {
+                hsize_t *offset = HDva_arg(arguments, hsize_t *);
+                hsize_t *chunk_nbytes = HDva_arg(arguments, hsize_t *);
+
+                dset = (H5D_t *)obj;
+
+                /* Make sure the dataset is chunked */
+                if(H5D_CHUNKED != dset->shared->layout.type)
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a chunked dataset")
+
+                /* Call private function */
+                if(H5D__get_chunk_storage_size(dset, offset, chunk_nbytes) < 0)
+                    HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't get storage size of chunk")
+
+                break;
+            }
+
+        case H5VL_NATIVE_DATASET_CHUNK_READ:
+            {
+                const       hsize_t *offset     = HDva_arg(arguments, hsize_t *);
+                uint32_t   *filters             = HDva_arg(arguments, uint32_t *);
+                void       *buf                 = HDva_arg(arguments, void *);
+                hsize_t     offset_copy[H5O_LAYOUT_NDIMS];  /* Internal copy of chunk offset */
+
+                dset = (H5D_t *)obj;
+
+                /* Check arguments */
+                if(NULL == dset->oloc.file)
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "dataset is not associated with a file")
+                if(H5D_CHUNKED != dset->shared->layout.type)
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a chunked dataset")
+
+                /* Copy the user's offset array so we can be sure it's terminated properly.
+                 * (we don't want to mess with the user's buffer).
+                 */
+                if(H5D__get_offset_copy(dset, offset, offset_copy) < 0)
+                    HGOTO_ERROR(H5E_DATASET, H5E_CANTALLOC, FAIL, "failure to copy offset array")
+
+                /* Read the raw chunk */
+                if(H5D__chunk_direct_read(dset, offset_copy, filters, buf) < 0)
+                    HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL, "can't read unprocessed chunk data")
+
+                break;
+            }
+
+        case H5VL_NATIVE_DATASET_CHUNK_WRITE:
+            {
+                uint32_t        filters             = HDva_arg(arguments, uint32_t);
+                const  hsize_t *offset              = HDva_arg(arguments, const hsize_t *);
+                uint32_t        data_size_32        = HDva_arg(arguments, uint32_t);
+                const void     *buf                 = HDva_arg(arguments, const void *);
+                hsize_t         offset_copy[H5O_LAYOUT_NDIMS];  /* Internal copy of chunk offset */
+
+                dset = (H5D_t *)obj;
+
+                /* Check arguments */
+                if(NULL == dset->oloc.file)
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "dataset is not associated with a file")
+                if(H5D_CHUNKED != dset->shared->layout.type)
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a chunked dataset")
+
+                /* Copy the user's offset array so we can be sure it's terminated properly.
+                 * (we don't want to mess with the user's buffer).
+                 */
+                if(H5D__get_offset_copy(dset, offset, offset_copy) < 0)
+                    HGOTO_ERROR(H5E_DATASET, H5E_CANTALLOC, FAIL, "failure to copy offset array")
+
+                /* Write chunk */
+                if(H5D__chunk_direct_write(dset, filters, offset_copy, data_size_32, buf) < 0)
+                    HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "can't write unprocessed chunk data")
+
+                break;
+            }
+
+        default:
+            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "invalid optional operation")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_dataset_optional() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_dataset_close
+ *
+ * Purpose:     Handles the dataset close callback
+ *
+ * Return:      Success:    SUCCEED
+ *              Failure:    FAIL (dataset will not be closed)
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_dataset_close(void *dset, hid_t H5_ATTR_UNUSED dxpl_id,
+    void H5_ATTR_UNUSED **req)
+{
+    herr_t ret_value = SUCCEED;                 /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    if(H5D_close((H5D_t*)dset) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTDEC, FAIL, "can't close dataset")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_dataset_close() */
+
diff --git a/src/H5VLnative_datatype.c b/src/H5VLnative_datatype.c
new file mode 100644
index 0000000..3c9463d
--- /dev/null
+++ b/src/H5VLnative_datatype.c
@@ -0,0 +1,265 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*
+ * Purpose:     Datatype callbacks for the native VOL connector
+ *
+ */
+
+#define H5T_FRIEND              /* Suppress error about including H5Tpkg    */
+
+#include "H5private.h"          /* Generic Functions                        */
+#include "H5Eprivate.h"         /* Error handling                           */
+#include "H5Gprivate.h"         /* Groups                                   */
+#include "H5Iprivate.h"         /* IDs                                      */
+#include "H5Oprivate.h"         /* Object headers                           */
+#include "H5Pprivate.h"         /* Property lists                           */
+#include "H5Tpkg.h"             /* Datatypes                                */
+#include "H5VLprivate.h"        /* Virtual Object Layer                     */
+
+#include "H5VLnative_private.h" /* Native VOL connector                     */
+
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_datatype_commit
+ *
+ * Purpose:     Handles the datatype commit callback
+ *
+ * Return:      Success:    datatype pointer
+ *              Failure:    NULL
+ *
+ *-------------------------------------------------------------------------
+ */
+void *
+H5VL__native_datatype_commit(void *obj, const H5VL_loc_params_t *loc_params, const char *name,
+    hid_t type_id, hid_t lcpl_id, hid_t tcpl_id, hid_t H5_ATTR_UNUSED tapl_id,
+    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
+{
+    H5G_loc_t   loc;                    /* Location to commit datatype */
+    H5T_t       *dt;                    /* Datatype for ID */
+    H5T_t       *type = NULL;           /* copy of the original type which will be committed */
+    void        *ret_value = NULL;      /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    /* check arguments */
+    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file or file object")
+
+    if(NULL == (dt = (H5T_t *)H5I_object_verify(type_id, H5I_DATATYPE)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a datatype")
+
+    /* Check arguments.  We cannot commit an immutable type because H5Tclose()
+     * normally fails on such types (try H5Tclose(H5T_NATIVE_INT)) but closing
+     * a named type should always succeed.
+     */
+    if(H5T_STATE_NAMED == dt->shared->state || H5T_STATE_OPEN == dt->shared->state)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "datatype is already committed")
+    if(H5T_STATE_IMMUTABLE == dt->shared->state)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "datatype is immutable")
+
+    /* Check for a "sensible" datatype to store on disk */
+    if(H5T_is_sensible(dt) <= 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "datatype is not sensible")
+
+    /* Copy the datatype - the copied one will be the type that is
+     * committed, and attached to original datatype above the VOL
+     * layer
+     */
+    if(NULL == (type = H5T_copy(dt, H5T_COPY_TRANSIENT)))
+        HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, NULL, "unable to copy");
+
+    /* Commit the datatype */
+    if(NULL != name) {
+        /* H5Tcommit */
+        if(H5T__commit_named(&loc, name, type, lcpl_id, tcpl_id) < 0)
+            HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, NULL, "unable to commit datatype")
+    } /* end if */
+    else {
+        /* H5Tcommit_anon */
+        if(H5T__commit_anon(loc.oloc->file, type, tcpl_id) < 0)
+            HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, NULL, "unable to commit datatype")
+    } /* end else */
+
+    ret_value = (void *)type;
+
+done:
+    if(NULL == ret_value && type)
+        H5T_close(type);
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_datatype_commit() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_datatype_open
+ *
+ * Purpose:     Handles the datatype open callback
+ *
+ * Return:      Success:    datatype pointer
+ *              Failure:    NULL
+ *
+ *-------------------------------------------------------------------------
+ */
+void *
+H5VL__native_datatype_open(void *obj, const H5VL_loc_params_t *loc_params, const char *name, 
+    hid_t H5_ATTR_UNUSED tapl_id, hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
+{
+    H5T_t       *type = NULL;           /* Datatype opened in file */
+    H5G_loc_t    loc;                   /* Group location of object to open */
+    void        *ret_value = NULL;
+
+    FUNC_ENTER_PACKAGE
+
+    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file or file object")
+
+    /* Open the datatype */
+    if(NULL == (type = H5T__open_name(&loc, name)))
+        HGOTO_ERROR(H5E_DATATYPE, H5E_CANTOPENOBJ, NULL, "unable to open named datatype")
+
+    type->vol_obj = NULL;
+
+    ret_value = (void *)type;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_datatype_open() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_datatype_get
+ *
+ * Purpose:     Handles the datatype get callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_datatype_get(void *obj, H5VL_datatype_get_t get_type, 
+    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
+{
+    H5T_t       *dt = (H5T_t *)obj;
+    herr_t       ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    switch (get_type) {
+        case H5VL_DATATYPE_GET_BINARY:
+            {
+                ssize_t *nalloc = HDva_arg(arguments, ssize_t *);
+                void *buf = HDva_arg(arguments, void *);
+                size_t size = HDva_arg(arguments, size_t);
+
+                if(H5T_encode(dt, (unsigned char *)buf, &size) < 0)
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't determine serialized length of datatype")
+
+                *nalloc = (ssize_t) size;
+                break;
+            }
+
+        /* H5Tget_create_plist */
+        case H5VL_DATATYPE_GET_TCPL:
+            {
+                hid_t *ret_id = HDva_arg(arguments, hid_t *);
+
+                if(H5I_INVALID_HID == (*ret_id = H5T__get_create_plist(dt)))
+                    HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, FAIL, "can't get object creation info");
+
+                break;
+            }
+
+        default:
+            HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't get this type of information from datatype")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_datatype_get() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_datatype_specific
+ *
+ * Purpose:     Handles the datatype specific callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_datatype_specific(void *obj, H5VL_datatype_specific_t specific_type, 
+                             hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
+{
+    H5T_t       *dt = (H5T_t *)obj;
+    herr_t       ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    switch(specific_type) {
+        case H5VL_DATATYPE_FLUSH:
+            {
+                hid_t type_id = HDva_arg(arguments, hid_t);
+
+                /* To flush metadata and invoke flush callback if there is */
+                if(H5O_flush_common(&dt->oloc, type_id) < 0)
+                    HGOTO_ERROR(H5E_DATATYPE, H5E_CANTFLUSH, FAIL, "unable to flush datatype")
+
+                break;
+            }
+
+        case H5VL_DATATYPE_REFRESH:
+            {
+                hid_t type_id = HDva_arg(arguments, hid_t);
+
+                /* Call private function to refresh datatype object */
+                if((H5O_refresh_metadata(type_id, dt->oloc)) < 0)
+                    HGOTO_ERROR(H5E_DATATYPE, H5E_CANTLOAD, FAIL, "unable to refresh datatype")
+
+                break;
+            }
+
+        default:
+            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "invalid specific operation")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_datatype_specific() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_datatype_close
+ *
+ * Purpose:     Handles the datatype close callback
+ *
+ * Return:      Success:    SUCCEED
+ *              Failure:    FAIL (datatype will not be closed)
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_datatype_close(void *dt, hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
+{
+    herr_t ret_value = SUCCEED;                 /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    if(H5T_close((H5T_t*)dt) < 0)
+        HGOTO_ERROR(H5E_SYM, H5E_CANTDEC, FAIL, "can't close datatype")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_datatype_close() */
+
diff --git a/src/H5VLnative_file.c b/src/H5VLnative_file.c
new file mode 100644
index 0000000..e7f27e1
--- /dev/null
+++ b/src/H5VLnative_file.c
@@ -0,0 +1,830 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*
+ * Purpose:     File callbacks for the native VOL connector
+ *
+ */
+
+#define H5F_FRIEND              /* Suppress error about including H5Fpkg    */
+
+#include "H5private.h"          /* Generic Functions                        */
+#include "H5ACprivate.h"        /* Metadata cache                           */
+#include "H5Cprivate.h"         /* Cache                                    */
+#include "H5Eprivate.h"         /* Error handling                           */
+#include "H5Fpkg.h"             /* Files                                    */
+#include "H5Gprivate.h"         /* Groups                                   */
+#include "H5Iprivate.h"         /* IDs                                      */
+#include "H5MFprivate.h"        /* File memory management                   */
+#include "H5Pprivate.h"         /* Property lists                           */
+#include "H5PBprivate.h"        /* Page buffering                           */
+#include "H5VLprivate.h"        /* Virtual Object Layer                     */
+
+#include "H5VLnative_private.h" /* Native VOL connector                     */
+
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_file_create
+ *
+ * Purpose:     Handles the file create callback
+ *
+ * Return:      Success:    file pointer
+ *              Failure:    NULL
+ *
+ *-------------------------------------------------------------------------
+ */
+void *
+H5VL__native_file_create(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id, 
+    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
+{
+    H5F_t *new_file = NULL;
+    void  *ret_value = NULL;
+
+    FUNC_ENTER_PACKAGE
+
+    /* Adjust bit flags by turning on the creation bit and making sure that
+     * the EXCL or TRUNC bit is set.  All newly-created files are opened for
+     * reading and writing.
+     */
+    if(0 == (flags & (H5F_ACC_EXCL|H5F_ACC_TRUNC)))
+        flags |= H5F_ACC_EXCL;              /* default */
+    flags |= H5F_ACC_RDWR | H5F_ACC_CREAT;
+
+    /* Create the file */ 
+    if(NULL == (new_file = H5F_open(name, flags, fcpl_id, fapl_id)))
+        HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to create file")
+    new_file->id_exists = TRUE;
+
+    ret_value = (void *)new_file;
+
+done:
+    if(NULL == ret_value && new_file) 
+        if(H5F__close(new_file) < 0)
+            HDONE_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, NULL, "problems closing file")
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_file_create() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_file_open
+ *
+ * Purpose:     Handles the file open callback
+ *
+ * Return:      Success:    file pointer
+ *              Failure:    NULL
+ *
+ *-------------------------------------------------------------------------
+ */
+void *
+H5VL__native_file_open(const char *name, unsigned flags, hid_t fapl_id,
+    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
+{
+    H5F_t *new_file = NULL;
+    void  *ret_value = NULL;
+
+    FUNC_ENTER_PACKAGE
+
+    /* Open the file */ 
+    if(NULL == (new_file = H5F_open(name, flags, H5P_FILE_CREATE_DEFAULT, fapl_id)))
+        HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to open file")
+    new_file->id_exists = TRUE;
+
+    ret_value = (void *)new_file;
+
+done:
+    if(NULL == ret_value && new_file && H5F_try_close(new_file, NULL) < 0)
+        HDONE_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, NULL, "problems closing file")
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_file_open() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_file_get
+ *
+ * Purpose:     Handles the file get callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_file_get(void *obj, H5VL_file_get_t get_type,
+    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
+{
+    H5F_t       *f = NULL;              /* File struct */
+    herr_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    switch(get_type) {
+        /* H5Fget_access_plist */
+        case H5VL_FILE_GET_FAPL:
+            {
+                H5P_genplist_t *new_plist;              /* New property list */
+                hid_t          *plist_id = HDva_arg(arguments, hid_t *);
+
+                f = (H5F_t *)obj;
+
+                /* Retrieve the file's access property list */
+                if((*plist_id = H5F_get_access_plist(f, TRUE)) < 0)
+                    HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get file access property list")
+
+                if(NULL == (new_plist = (H5P_genplist_t *)H5I_object(*plist_id)))
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a property list")
+                break;
+            }
+
+        /* H5Fget_create_plist */
+        case H5VL_FILE_GET_FCPL:
+            {
+                H5P_genplist_t *plist;      /* Property list */
+                hid_t          *plist_id = HDva_arg(arguments, hid_t *);
+
+                f = (H5F_t *)obj;
+                if(NULL == (plist = (H5P_genplist_t *)H5I_object(f->shared->fcpl_id)))
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a property list")
+
+                /* Create the property list object to return */
+                if((*plist_id = H5P_copy_plist(plist, TRUE)) < 0)
+                    HGOTO_ERROR(H5E_PLIST, H5E_CANTINIT, FAIL, "unable to copy file creation properties")
+
+                break;
+            }
+
+        /* H5Fget_obj_count */
+        case H5VL_FILE_GET_OBJ_COUNT:
+            {
+                unsigned    types = HDva_arg(arguments, unsigned);
+                ssize_t    *ret = HDva_arg(arguments, ssize_t *);
+                size_t      obj_count = 0;      /* Number of opened objects */
+
+                f = (H5F_t *)obj;
+                /* Perform the query */
+                if(H5F_get_obj_count(f, types, TRUE, &obj_count) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_BADITER, FAIL, "H5F_get_obj_count failed")
+
+                /* Set the return value */
+                *ret = (ssize_t)obj_count;
+                break;
+            }
+
+        /* H5Fget_obj_ids */
+        case H5VL_FILE_GET_OBJ_IDS:
+            {
+                unsigned    types = HDva_arg(arguments, unsigned);
+                size_t      max_objs = HDva_arg(arguments, size_t);
+                hid_t      *oid_list = HDva_arg(arguments, hid_t *);
+                ssize_t    *ret = HDva_arg(arguments, ssize_t *);
+                size_t      obj_count = 0;      /* Number of opened objects */
+
+                f = (H5F_t *)obj;
+                /* Perform the query */
+                if(H5F_get_obj_ids(f, types, max_objs, oid_list, TRUE, &obj_count) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_BADITER, FAIL, "H5F_get_obj_ids failed")
+
+                /* Set the return value */
+                *ret = (ssize_t)obj_count;
+                break;
+            }
+
+        /* H5Fget_intent */
+        case H5VL_FILE_GET_INTENT:
+            {
+                unsigned *intent_flags = HDva_arg(arguments, unsigned *);
+
+                f = (H5F_t *)obj;
+
+                /* HDF5 uses some flags internally that users don't know about.
+                 * Simplify things for them so that they only get either H5F_ACC_RDWR
+                 * or H5F_ACC_RDONLY and any SWMR flags.
+                 */
+                if(H5F_INTENT(f) & H5F_ACC_RDWR) {
+                    *intent_flags = H5F_ACC_RDWR;
+
+                    /* Check for SWMR write access on the file */
+                    if(H5F_INTENT(f) & H5F_ACC_SWMR_WRITE)
+                        *intent_flags |= H5F_ACC_SWMR_WRITE;
+                } /* end if */
+                else {
+                    *intent_flags = H5F_ACC_RDONLY;
+
+                    /* Check for SWMR read access on the file */
+                    if(H5F_INTENT(f) & H5F_ACC_SWMR_READ)
+                        *intent_flags |= H5F_ACC_SWMR_READ;
+                } /* end else */
+
+                break;
+            }
+
+        /* H5Fget_name */
+        case H5VL_FILE_GET_NAME:
+            {
+                H5I_type_t  type = (H5I_type_t)HDva_arg(arguments, int); /* enum work-around */
+                size_t      size = HDva_arg(arguments, size_t);
+                char       *name = HDva_arg(arguments, char *);
+                ssize_t    *ret  = HDva_arg(arguments, ssize_t *);
+                size_t      len;
+
+                if(NULL == (f = H5F__get_file(obj, type)))
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+                len = HDstrlen(H5F_OPEN_NAME(f));
+
+                if(name) {
+                    HDstrncpy(name, H5F_OPEN_NAME(f), MIN(len + 1,size));
+                    if(len >= size)
+                        name[size-1]='\0';
+                } /* end if */
+
+                /* Set the return value for the API call */
+                *ret = (ssize_t)len;
+                break;
+            }
+
+        default:
+            HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't get this type of information")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_file_get() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_file_specific
+ *
+ * Purpose:     Handles the file specific callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_file_specific(void *obj, H5VL_file_specific_t specific_type,
+    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
+{
+    herr_t       ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    switch(specific_type) {
+        /* H5Fflush */
+        case H5VL_FILE_FLUSH:
+            {
+                H5I_type_t      type = (H5I_type_t)HDva_arg(arguments, int); /* enum work-around */
+                H5F_scope_t     scope = (H5F_scope_t)HDva_arg(arguments, int); /* enum work-around */
+                H5F_t           *f = NULL;              /* File to flush */
+
+                /* Get the file for the object */
+                if(NULL == (f = H5F__get_file(obj, type)))
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+                /* Nothing to do if the file is read only. This determination is
+                 * made at the shared open(2) flags level, implying that opening a
+                 * file twice, once for read-only and once for read-write, and then
+                 * calling H5Fflush() with the read-only handle, still causes data
+                 * to be flushed.
+                 */
+                 if(H5F_ACC_RDWR & H5F_INTENT(f)) {
+                     /* Flush other files, depending on scope */
+                     if(H5F_SCOPE_GLOBAL == scope) {
+                         /* Call the flush routine for mounted file hierarchies */
+                         if(H5F_flush_mounts(f) < 0)
+                             HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush mounted file hierarchy")
+                     } /* end if */
+                     else {
+                         /* Call the flush routine, for this file */
+                         if(H5F__flush(f) < 0)
+                             HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush file's cached information")
+                     } /* end else */
+                 } /* end if */
+                break;
+            }
+
+        /* H5Freopen */
+        case H5VL_FILE_REOPEN:
+            {
+                void   **ret        = HDva_arg(arguments, void **);
+                H5F_t  *new_file    = NULL;
+
+                /* Reopen the file through the VOL connector */
+                if(NULL == (new_file = H5F__reopen((H5F_t *)obj)))
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to reopen file")
+                new_file->id_exists = TRUE;
+
+                *ret = (void *)new_file;
+                break;
+            }
+
+        /* H5Fmount */
+        case H5VL_FILE_MOUNT:
+            {
+                H5I_type_t  type       = (H5I_type_t)HDva_arg(arguments, int); /* enum work-around */
+                const char *name       = HDva_arg(arguments, const char *);
+                H5F_t      *child      = HDva_arg(arguments, H5F_t *);
+                hid_t       plist_id   = HDva_arg(arguments, hid_t);
+                H5G_loc_t   loc;
+
+                if(H5G_loc_real(obj, type, &loc) < 0)
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+                /* Do the mount */
+                if(H5F__mount(&loc, name, child, plist_id) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "unable to mount file")
+
+                break;
+            }
+
+        /* H5Funmount */
+        case H5VL_FILE_UNMOUNT:
+            {
+                H5I_type_t  type       = (H5I_type_t)HDva_arg(arguments, int); /* enum work-around */
+                const char *name       = HDva_arg(arguments, const char *);
+                H5G_loc_t   loc;
+
+                if(H5G_loc_real(obj, type, &loc) < 0)
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+                /* Unmount */
+                if(H5F__unmount(&loc, name) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "unable to unmount file")
+
+                break;
+            }
+
+        /* H5Fis_accessible */
+        case H5VL_FILE_IS_ACCESSIBLE:
+            {
+                hid_t       fapl_id = HDva_arg(arguments, hid_t);
+                const char *name    = HDva_arg(arguments, const char *);
+                htri_t     *ret     = HDva_arg(arguments, htri_t *);
+
+                /* Call private routine */
+                if((*ret = H5F__is_hdf5(name, fapl_id)) < 0)
+                    HGOTO_ERROR(H5E_IO, H5E_CANTINIT, FAIL, "error in HDF5 file check")
+                break;
+            }
+
+
+
+        default:
+            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "invalid specific operation")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_file_specific() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_file_optional
+ *
+ * Purpose:     Handles the file optional callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_file_optional(void *obj, hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
+{
+    H5F_t *f = NULL;           /* File */
+    H5VL_native_file_optional_t optional_type = HDva_arg(arguments, H5VL_native_file_optional_t);
+    herr_t ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    f = (H5F_t *)obj;
+    switch(optional_type) {
+        /* H5Fget_filesize */
+        case H5VL_NATIVE_FILE_GET_SIZE:
+            {
+                haddr_t     max_eof_eoa;            /* Maximum of the EOA & EOF */
+                haddr_t     base_addr;              /* Base address for the file */
+                hsize_t    *size = HDva_arg(arguments, hsize_t *);
+
+                /* Go get the actual file size */
+                if(H5F__get_max_eof_eoa(f, &max_eof_eoa) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "file can't get max eof/eoa ")
+
+                base_addr = H5FD_get_base_addr(f->shared->lf);
+
+                if(size)
+                    *size = (hsize_t)(max_eof_eoa + base_addr);     /* Convert relative base address for file to absolute address */
+
+                break;
+            }
+
+        /* H5Fget_file_image */
+        case H5VL_NATIVE_FILE_GET_FILE_IMAGE:
+            {
+                void       *buf_ptr   = HDva_arg(arguments, void *);
+                ssize_t    *ret       = HDva_arg(arguments, ssize_t *);
+                size_t      buf_len   = HDva_arg(arguments, size_t );
+
+                /* Do the actual work */
+                if((*ret = H5F__get_file_image(f, buf_ptr, buf_len)) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "get file image failed")
+                break;
+            }
+
+        /* H5Fget_freespace */
+        case H5VL_NATIVE_FILE_GET_FREE_SPACE:
+            {
+                hsize_t     tot_space;  /* Amount of free space in the file */
+                hssize_t    *ret = HDva_arg(arguments, hssize_t *);
+
+                /* Go get the actual amount of free space in the file */
+                if(H5MF_get_freespace(f, &tot_space, NULL) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to check free space for file")
+                *ret = (hssize_t)tot_space;
+                break;
+            }
+
+        /* H5Fget_free_sections */
+        case H5VL_NATIVE_FILE_GET_FREE_SECTIONS:
+            {
+                H5F_sect_info_t *sect_info = HDva_arg(arguments, H5F_sect_info_t *);
+                ssize_t         *ret       = HDva_arg(arguments, ssize_t *);
+                H5F_mem_t       type       = (H5F_mem_t)HDva_arg(arguments, int); /* enum work-around */
+                size_t          nsects     = HDva_arg(arguments, size_t);
+
+                /* Go get the free-space section information in the file */
+                if((*ret = H5MF_get_free_sections(f, type, nsects, sect_info)) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to check free space for file")
+                break;
+            }
+
+        /* H5Fget_info1/2 */
+        case H5VL_NATIVE_FILE_GET_INFO:
+            {
+                H5I_type_t  type   = (H5I_type_t)HDva_arg(arguments, int); /* enum work-around */
+                H5F_info2_t *finfo = HDva_arg(arguments, H5F_info2_t *);
+
+                /* Get the file struct. This call is careful to not return the file pointer
+                 * for the top file in a mount hierarchy.
+                 */
+                if(NULL == (f = H5F__get_file(obj, type)))
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "could not get a file struct")
+
+                /* Get the file info */
+                if(H5F__get_info(f, finfo) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to retrieve file info")
+
+                break;
+            }
+
+        /* H5Fget_mdc_config */
+        case H5VL_NATIVE_FILE_GET_MDC_CONF:
+            {
+                H5AC_cache_config_t *config_ptr = HDva_arg(arguments, H5AC_cache_config_t *);
+
+                /* Go get the resize configuration */
+                if(H5AC_get_cache_auto_resize_config(f->shared->cache, config_ptr) < 0)
+                    HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "H5AC_get_cache_auto_resize_config() failed.")
+                break;
+            }
+
+        /* H5Fget_mdc_hit_rate */
+        case H5VL_NATIVE_FILE_GET_MDC_HR:
+            {
+                double *hit_rate_ptr = HDva_arg(arguments, double *);
+
+                /* Go get the current hit rate */
+                if(H5AC_get_cache_hit_rate(f->shared->cache, hit_rate_ptr) < 0)
+                    HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "H5AC_get_cache_hit_rate() failed.")
+                break;
+            }
+
+        /* H5Fget_mdc_size */
+        case H5VL_NATIVE_FILE_GET_MDC_SIZE:
+            {
+                size_t *max_size_ptr        = HDva_arg(arguments, size_t *);
+                size_t *min_clean_size_ptr  = HDva_arg(arguments, size_t *);
+                size_t *cur_size_ptr        = HDva_arg(arguments, size_t *); 
+                int    *cur_num_entries_ptr = HDva_arg(arguments, int *); 
+                uint32_t cur_num_entries;
+
+                /* Go get the size data */
+                if(H5AC_get_cache_size(f->shared->cache, max_size_ptr, min_clean_size_ptr, 
+                                       cur_size_ptr, &cur_num_entries) < 0)
+                    HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "H5AC_get_cache_size() failed.")
+
+                if(cur_num_entries_ptr != NULL)
+                    *cur_num_entries_ptr = (int)cur_num_entries;
+                break;
+            }
+
+        /* H5Fget_vfd_handle */
+        case H5VL_NATIVE_FILE_GET_VFD_HANDLE:
+            {
+                void **file_handle  = HDva_arg(arguments, void **);
+                hid_t  fapl_id      = HDva_arg(arguments, hid_t);
+
+                /* Retrieve the VFD handle for the file */
+                if(H5F_get_vfd_handle(f, fapl_id, file_handle) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't retrieve VFD handle")
+                break;
+            }
+
+        /* H5Iget_file_id */
+        case H5VL_NATIVE_FILE_GET_FILE_ID:
+            {
+                H5I_type_t  type = (H5I_type_t)HDva_arg(arguments, int); /* enum work-around */
+                hid_t      *file_id = HDva_arg(arguments, hid_t *);
+
+                if(NULL == (f = H5F__get_file(obj, type)))
+                    HGOTO_ERROR(H5E_FILE, H5E_BADTYPE, FAIL, "not a file or file object")
+                if((*file_id = H5F__get_file_id(f)) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't get file ID")
+                break;
+            }
+
+        /* H5Fclear_elink_file_cache */
+        case H5VL_NATIVE_FILE_CLEAR_ELINK_CACHE:
+            {
+                /* Release the EFC */
+                if(f->shared->efc)
+                    if(H5F__efc_release(f->shared->efc) < 0)
+                        HGOTO_ERROR(H5E_FILE, H5E_CANTRELEASE, FAIL, "can't release external file cache")
+                break;
+            }
+
+        /* H5Freset_mdc_hit_rate_stats */
+        case H5VL_NATIVE_FILE_RESET_MDC_HIT_RATE:
+            {
+                /* Reset the hit rate statistic */
+                if(H5AC_reset_cache_hit_rate_stats(f->shared->cache) < 0)
+                    HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "can't reset cache hit rate")
+                break;
+            }
+
+        /* H5Fset_mdc_config */
+        case H5VL_NATIVE_FILE_SET_MDC_CONFIG:
+            {
+                H5AC_cache_config_t *config_ptr = HDva_arg(arguments, H5AC_cache_config_t *);
+
+                /* set the resize configuration  */
+                if(H5AC_set_cache_auto_resize_config(f->shared->cache, config_ptr) < 0)
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "H5AC_set_cache_auto_resize_config() failed")
+                break;
+            }
+
+        /* H5Fget_metadata_read_retry_info */
+        case H5VL_NATIVE_FILE_GET_METADATA_READ_RETRY_INFO:
+            {
+                H5F_retry_info_t *info = HDva_arg(arguments, H5F_retry_info_t *);
+
+                if(H5F_get_metadata_read_retry_info(f, info) < 0)
+                    HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "can't get metadata read retry info")
+
+                break;
+            }
+
+        /* H5Fstart_swmr_write */
+        case H5VL_NATIVE_FILE_START_SWMR_WRITE:
+            {
+                if(H5F__start_swmr_write(f) < 0)
+                    HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "can't start SWMR write")
+
+                break;
+            }
+
+        /* H5Fstart_mdc_logging */
+        case H5VL_NATIVE_FILE_START_MDC_LOGGING:
+            {
+                /* Call mdc logging function */
+                if(H5C_start_logging(f->shared->cache) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_LOGGING, FAIL, "unable to start mdc logging")
+
+                break;
+            }
+
+        /* H5Fstop_mdc_logging */
+        case H5VL_NATIVE_FILE_STOP_MDC_LOGGING:
+            {
+                /* Call mdc logging function */
+                if(H5C_stop_logging(f->shared->cache) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_LOGGING, FAIL, "unable to stop mdc logging")
+
+                break;
+            }
+
+        /* H5Fget_mdc_logging_status */
+        case H5VL_NATIVE_FILE_GET_MDC_LOGGING_STATUS:
+            {
+                hbool_t *is_enabled             = HDva_arg(arguments, hbool_t *);
+                hbool_t *is_currently_logging   = HDva_arg(arguments, hbool_t *);
+
+                /* Call mdc logging function */
+                if(H5C_get_logging_status(f->shared->cache, is_enabled, is_currently_logging) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_LOGGING, FAIL, "unable to get logging status")
+
+                break;
+            }
+
+        /* H5Fformat_convert */
+        case H5VL_NATIVE_FILE_FORMAT_CONVERT:
+            {
+                /* Convert the format */
+                if(H5F__format_convert(f) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTCONVERT, FAIL, "can't convert file format")
+
+                break;
+            }
+
+        /* H5Freset_page_buffering_stats */
+        case H5VL_NATIVE_FILE_RESET_PAGE_BUFFERING_STATS:
+            {
+                /* Sanity check */
+                if(NULL == f->shared->page_buf)
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "page buffering not enabled on file")
+
+                /* Reset the statistics */
+                if(H5PB_reset_stats(f->shared->page_buf) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't reset stats for page buffering")
+
+                break;
+            }
+
+        /* H5Fget_page_buffering_stats */
+        case H5VL_NATIVE_FILE_GET_PAGE_BUFFERING_STATS:
+            {
+                unsigned *accesses      = HDva_arg(arguments, unsigned *);
+                unsigned *hits          = HDva_arg(arguments, unsigned *);
+                unsigned *misses        = HDva_arg(arguments, unsigned *);
+                unsigned *evictions     = HDva_arg(arguments, unsigned *);
+                unsigned *bypasses      = HDva_arg(arguments, unsigned *);
+                
+                /* Sanity check */
+                if(NULL == f->shared->page_buf)
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "page buffering not enabled on file")
+
+                /* Get the statistics */
+                if(H5PB_get_stats(f->shared->page_buf, accesses, hits, misses, evictions, bypasses) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't retrieve stats for page buffering")
+
+                break;
+            }
+
+        /* H5Fget_mdc_image_info */
+        case H5VL_NATIVE_FILE_GET_MDC_IMAGE_INFO:
+            {
+                haddr_t *image_addr = HDva_arg(arguments, haddr_t *);
+                hsize_t *image_len = HDva_arg(arguments, hsize_t *);
+
+                /* Go get the address and size of the cache image */
+                if(H5AC_get_mdc_image_info(f->shared->cache, image_addr, image_len) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't retrieve cache image info")
+
+                break;
+            }
+
+        /* H5Fget_eoa */
+        case H5VL_NATIVE_FILE_GET_EOA:
+            {
+                haddr_t *eoa = HDva_arg(arguments, haddr_t *);
+                haddr_t rel_eoa;        /* Relative address of EOA */
+
+                /* Sanity check */
+                HDassert(eoa);
+
+                /* This routine will work only for drivers with this feature enabled.*/
+                /* We might introduce a new feature flag in the future */
+                if(!H5F_HAS_FEATURE(f, H5FD_FEAT_SUPPORTS_SWMR_IO))
+                    HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "must use a SWMR-compatible VFD for this public routine")
+
+                /* The real work */
+                if(HADDR_UNDEF == (rel_eoa = H5F_get_eoa(f, H5FD_MEM_DEFAULT)))
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "get_eoa request failed")
+
+                /* Set return value */
+                /* (Note compensating for base address subtraction in internal routine) */
+                *eoa = rel_eoa + H5F_get_base_addr(f);
+
+                break;
+            }
+
+        /* H5Fincrement_filesize */
+        case H5VL_NATIVE_FILE_INCR_FILESIZE:
+            {
+                hsize_t increment = HDva_arg(arguments, hsize_t);
+                haddr_t max_eof_eoa;        /* Maximum of the relative EOA & EOF */
+
+                /* This public routine will work only for drivers with this feature enabled.*/
+                /* We might introduce a new feature flag in the future */
+                if(!H5F_HAS_FEATURE(f, H5FD_FEAT_SUPPORTS_SWMR_IO))
+                    HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "must use a SWMR-compatible VFD for this public routine")
+
+                /* Get the maximum of EOA and EOF */
+                if(H5F__get_max_eof_eoa(f, &max_eof_eoa) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "file can't get max eof/eoa ")
+
+                /* Set EOA to the maximum value + increment */
+                if(H5F__set_eoa(f, H5FD_MEM_DEFAULT, max_eof_eoa + increment) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "driver set_eoa request failed")
+
+                break;
+            }
+
+        /* H5Fset_latest_format, H5Fset_libver_bounds */
+        case H5VL_NATIVE_FILE_SET_LIBVER_BOUNDS:
+            {
+                H5F_libver_t low = (H5F_libver_t)HDva_arg(arguments, int); /* enum work-around */
+                H5F_libver_t high = (H5F_libver_t)HDva_arg(arguments, int); /* enum work-around */
+
+                /* Call internal set_libver_bounds function */
+                if(H5F__set_libver_bounds(f, low, high) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "cannot set low/high bounds")
+
+                break;
+            }
+
+        /* H5Fget_dset_no_attrs_hint */
+        case H5VL_NATIVE_FILE_GET_MIN_DSET_OHDR_FLAG:
+            {
+                hbool_t *minimize = va_arg(arguments, hbool_t *);
+                *minimize = H5F_GET_MIN_DSET_OHDR(f);
+                break;
+            }
+
+        /* H5Fset_dset_no_attrs_hint */
+        case H5VL_NATIVE_FILE_SET_MIN_DSET_OHDR_FLAG:
+            {
+                int minimize = va_arg(arguments, int);
+                if(H5F_set_min_dset_ohdr(f, (hbool_t)minimize) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "cannot set file's dataset object header minimization flag")
+                break;
+            }
+
+        default:
+            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "invalid optional operation")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_file_optional() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_file_close
+ *
+ * Purpose:     Handles the file close callback
+ *
+ * Return:      Success:    SUCCEED
+ *              Failure:    FAIL (file will not be closed)
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_file_close(void *file, hid_t H5_ATTR_UNUSED dxpl_id,
+    void H5_ATTR_UNUSED **req)
+{
+    int     nref;
+    H5F_t   *f          = (H5F_t *)file;
+    hid_t   file_id     = H5I_INVALID_HID;
+    herr_t  ret_value   = SUCCEED;                  /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    /* This routine should only be called when a file ID's ref count drops to zero */
+    HDassert(H5F_ID_EXISTS(f));
+
+    /* Flush file if this is the last reference to this id and we have write
+     * intent, unless it will be flushed by the "shared" file being closed.
+     * This is only necessary to replicate previous behaviour, and could be
+     * disabled by an option/property to improve performance.
+     */
+    if((H5F_NREFS(f) > 1) && (H5F_INTENT(f) & H5F_ACC_RDWR)) {
+        /* Get the file ID corresponding to the H5F_t struct */
+        if(H5I_find_id(f, H5I_FILE, &file_id) < 0 || H5I_INVALID_HID == file_id)
+            HGOTO_ERROR(H5E_ATOM, H5E_CANTGET, FAIL, "invalid atom")
+
+        /* Get the number of references outstanding for this file ID */
+        if((nref = H5I_get_ref(file_id, FALSE)) < 0)
+            HGOTO_ERROR(H5E_ATOM, H5E_CANTGET, FAIL, "can't get ID ref count")
+        if(nref == 1)
+            if(H5F__flush(f) < 0)
+                HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "unable to flush cache")
+    } /* end if */
+
+    /* Close the file */
+    if(H5F__close(f) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTDEC, FAIL, "can't close file")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_file_close() */
+
diff --git a/src/H5VLnative_group.c b/src/H5VLnative_group.c
new file mode 100644
index 0000000..9c07b3d
--- /dev/null
+++ b/src/H5VLnative_group.c
@@ -0,0 +1,363 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*
+ * Purpose:     Group callbacks for the native VOL connector
+ *
+ */
+
+#define H5G_FRIEND              /* Suppress error about including H5Gpkg    */
+
+#include "H5private.h"          /* Generic Functions                        */
+#include "H5Eprivate.h"         /* Error handling                           */
+#include "H5Gpkg.h"             /* Groups                                   */
+#include "H5Iprivate.h"         /* IDs                                      */
+#include "H5Oprivate.h"         /* Object headers                           */
+#include "H5Pprivate.h"         /* Property lists                           */
+#include "H5VLprivate.h"        /* Virtual Object Layer                     */
+
+#include "H5VLnative_private.h" /* Native VOL connector                     */
+
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_group_create
+ *
+ * Purpose:     Handles the group create callback
+ *
+ * Return:      Success:    group pointer
+ *              Failure:    NULL
+ *
+ *-------------------------------------------------------------------------
+ */
+void *
+H5VL__native_group_create(void *obj, const H5VL_loc_params_t *loc_params, const char *name,
+    hid_t gcpl_id, hid_t H5_ATTR_UNUSED gapl_id, hid_t H5_ATTR_UNUSED dxpl_id,
+    void H5_ATTR_UNUSED **req)
+{
+    H5P_genplist_t *plist;              /* Property list pointer        */
+    H5G_loc_t       loc;                /* Location to create group     */
+    H5G_t          *grp = NULL;         /* New group created            */
+    hid_t           lcpl_id;
+    void           *ret_value;
+
+    FUNC_ENTER_PACKAGE
+
+    /* Get the property list structure */
+    if(NULL == (plist = (H5P_genplist_t *)H5I_object(gcpl_id)))
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, NULL, "can't find object for ID")
+
+    /* Get creation properties */
+    if(H5P_get(plist, H5VL_PROP_GRP_LCPL_ID, &lcpl_id) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get property value for lcpl id")
+
+    /* Set up the location */
+    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file or file object")
+
+    /* if name is NULL then this is from H5Gcreate_anon */
+    if(name == NULL) {
+        H5G_obj_create_t gcrt_info;         /* Information for group creation */
+
+        /* Set up group creation info */
+        gcrt_info.gcpl_id = gcpl_id;
+        gcrt_info.cache_type = H5G_NOTHING_CACHED;
+        HDmemset(&gcrt_info.cache, 0, sizeof(gcrt_info.cache));
+
+        /* Create the new group & get its ID */
+        if(NULL == (grp = H5G__create(loc.oloc->file, &gcrt_info)))
+            HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, NULL, "unable to create group")            
+    } /* end if */
+    /* otherwise it's from H5Gcreate */
+    else {
+        /* Create the new group & get its ID */
+        if(NULL == (grp = H5G__create_named(&loc, name, lcpl_id, gcpl_id)))
+            HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, NULL, "unable to create group")
+    } /* end else */
+
+    ret_value = (void *)grp;
+
+done:
+    if(name == NULL) {
+        /* Release the group's object header, if it was created */
+        if(grp) {
+            H5O_loc_t *oloc;         /* Object location for group */
+
+            /* Get the new group's object location */
+            if(NULL == (oloc = H5G_oloc(grp)))
+                HDONE_ERROR(H5E_SYM, H5E_CANTGET, NULL, "unable to get object location of group")
+
+            /* Decrement refcount on group's object header in memory */
+            if(H5O_dec_rc_by_loc(oloc) < 0)
+                HDONE_ERROR(H5E_SYM, H5E_CANTDEC, NULL, "unable to decrement refcount on newly created object")
+         } /* end if */
+    } /* end if */
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_group_create() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_group_open
+ *
+ * Purpose:     Handles the group open callback
+ *
+ * Return:      Success:    group pointer
+ *              Failure:    NULL
+ *
+ *-------------------------------------------------------------------------
+ */
+void *
+H5VL__native_group_open(void *obj, const H5VL_loc_params_t *loc_params, const char *name, 
+    hid_t H5_ATTR_UNUSED gapl_id, hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
+{
+    H5G_loc_t       loc;                /* Location to open group   */
+    H5G_t          *grp = NULL;         /* New group opend          */
+    void           *ret_value;
+
+    FUNC_ENTER_PACKAGE
+
+    /* Set up the location */
+    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file or file object")
+
+    /* Open the group */
+    if((grp = H5G__open_name(&loc, name)) == NULL)
+        HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, NULL, "unable to open group")
+
+    ret_value = (void *)grp;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_group_open() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_group_get
+ *
+ * Purpose:     Handles the group get callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_group_get(void *obj, H5VL_group_get_t get_type,
+    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
+{
+    herr_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    switch(get_type) {
+        /* H5Gget_create_plist */
+        case H5VL_GROUP_GET_GCPL:
+            {
+                hid_t      *new_gcpl_id     = HDva_arg(arguments, hid_t *);
+                H5G_t      *grp             = (H5G_t *)obj;
+
+                if((*new_gcpl_id = H5G_get_create_plist(grp)) < 0)
+                    HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get creation property list for group")
+                break;
+            }
+
+        /* H5Gget_info */
+        case H5VL_GROUP_GET_INFO:
+            {
+                const H5VL_loc_params_t  *loc_params  = HDva_arg(arguments, const H5VL_loc_params_t *);
+                H5G_info_t         *group_info  = HDva_arg(arguments, H5G_info_t *);
+                H5G_loc_t           loc;
+
+                if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+                if(loc_params->type == H5VL_OBJECT_BY_SELF) {
+                    /* H5Gget_info */
+
+                    /* Retrieve the group's information */
+                    if(H5G__obj_info(loc.oloc, group_info) < 0)
+                        HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't retrieve group info")
+                } /* end if */
+                else if(loc_params->type == H5VL_OBJECT_BY_NAME) {
+                    /* H5Gget_info_by_name */
+
+                    /* Retrieve the group's information */
+                    if(H5G__get_info_by_name(&loc, loc_params->loc_data.loc_by_name.name, group_info) < 0)
+                        HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't retrieve group info")
+                } /* end else-if */
+                else if(loc_params->type == H5VL_OBJECT_BY_IDX) {
+                    /* H5Gget_info_by_idx */
+
+                    /* Retrieve the group's information */
+                    if(H5G__get_info_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, loc_params->loc_data.loc_by_idx.idx_type,
+                            loc_params->loc_data.loc_by_idx.order, loc_params->loc_data.loc_by_idx.n, group_info) < 0)
+                        HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't retrieve group info")
+                } /* end else-if */
+                else
+                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown get info parameters")
+                break;
+            }
+
+        default:
+            HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't get this type of information from group")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_group_get() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_group_specific
+ *
+ * Purpose:     Handles the group specific callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_group_specific(void *obj, H5VL_group_specific_t specific_type, 
+                             hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
+{
+    H5G_t       *grp = (H5G_t *)obj;
+    herr_t       ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    switch(specific_type) {
+        case H5VL_GROUP_FLUSH:
+            {
+                hid_t group_id = HDva_arg(arguments, hid_t);
+
+                /* Flush object's metadata to file */
+                if(H5O_flush_common(&grp->oloc, group_id) < 0)
+                    HGOTO_ERROR(H5E_SYM, H5E_CANTFLUSH, FAIL, "unable to flush group")
+
+                break;
+            }
+
+        case H5VL_GROUP_REFRESH:
+            {
+                hid_t group_id = HDva_arg(arguments, hid_t);
+
+                /* Call private function to refresh group object */
+                if((H5O_refresh_metadata(group_id, grp->oloc)) < 0)
+                    HGOTO_ERROR(H5E_SYM, H5E_CANTLOAD, FAIL, "unable to refresh group")
+
+                break;
+            }
+
+        default:
+            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "invalid specific operation")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_group_specific() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_group_optional
+ *
+ * Purpose:     Handles the group optional callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_group_optional(void *obj, hid_t H5_ATTR_UNUSED dxpl_id,
+    void H5_ATTR_UNUSED **req, va_list arguments)
+{
+    H5VL_native_group_optional_t optional_type;
+    herr_t ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    optional_type = HDva_arg(arguments, H5VL_native_group_optional_t);
+    switch(optional_type) {
+#ifndef H5_NO_DEPRECATED_SYMBOLS
+        /* H5Giterate (deprecated) */
+        case H5VL_NATIVE_GROUP_ITERATE_OLD:
+            {
+                const H5VL_loc_params_t *loc_params = HDva_arg(arguments, const H5VL_loc_params_t *);
+                hsize_t idx = HDva_arg(arguments, hsize_t);
+                hsize_t *last_obj = HDva_arg(arguments, hsize_t *);
+                const H5G_link_iterate_t *lnk_op = HDva_arg(arguments, const H5G_link_iterate_t *);
+                void *op_data = HDva_arg(arguments, void *);
+                H5G_loc_t grp_loc;
+
+                /* Get the location struct for the object */
+                if(H5G_loc_real(obj, loc_params->obj_type, &grp_loc) < 0)
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+                /* Call the actual iteration routine */
+                if((ret_value = H5G_iterate(&grp_loc, loc_params->loc_data.loc_by_name.name, H5_INDEX_NAME, H5_ITER_INC, idx, last_obj, lnk_op, op_data)) < 0)
+                    HERROR(H5E_VOL, H5E_BADITER, "error iterating over group's links");
+
+                break;
+            }
+
+        /* H5Gget_objinfo (deprecated) */
+        case H5VL_NATIVE_GROUP_GET_OBJINFO:
+            {
+                const H5VL_loc_params_t *loc_params = HDva_arg(arguments, const H5VL_loc_params_t *);
+                hbool_t follow_link = (hbool_t)HDva_arg(arguments, unsigned);
+                H5G_stat_t *statbuf = HDva_arg(arguments, H5G_stat_t *);
+                H5G_loc_t grp_loc;
+
+                /* Get the location struct for the object */
+                if(H5G_loc_real(obj, loc_params->obj_type, &grp_loc) < 0)
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+                /* Call the actual group objinfo routine */
+                if(H5G__get_objinfo(&grp_loc, loc_params->loc_data.loc_by_name.name, follow_link, statbuf) < 0)
+                    HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "cannot stat object")
+
+                break;
+            }
+#endif /* H5_NO_DEPRECATED_SYMBOLS */
+
+        default:
+            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "invalid optional operation")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_group_optional() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_group_close
+ *
+ * Purpose:     Handles the group close callback
+ *
+ * Return:      Success:    SUCCEED
+ *              Failure:    FAIL (group will not be closed)
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_group_close(void *grp, hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
+{
+    herr_t ret_value = SUCCEED;                 /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    if(H5G_close((H5G_t *)grp) < 0)
+        HGOTO_ERROR(H5E_SYM, H5E_CLOSEERROR, FAIL, "can't close group")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_group_close() */
+
diff --git a/src/H5VLnative_link.c b/src/H5VLnative_link.c
new file mode 100644
index 0000000..98d2ccd
--- /dev/null
+++ b/src/H5VLnative_link.c
@@ -0,0 +1,435 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*
+ * Purpose:     Link callbacks for the native VOL connector
+ *
+ */
+
+#define H5L_FRIEND              /* Suppress error about including H5Lpkg    */
+
+#include "H5private.h"          /* Generic Functions                        */
+#include "H5Eprivate.h"         /* Error handling                           */
+#include "H5Gprivate.h"         /* Groups                                   */
+#include "H5Iprivate.h"         /* IDs                                      */
+#include "H5Lpkg.h"             /* Links                                    */
+#include "H5Pprivate.h"         /* Property lists                           */
+#include "H5VLprivate.h"        /* Virtual Object Layer                     */
+
+#include "H5VLnative_private.h" /* Native VOL connector                     */
+
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_link_create
+ *
+ * Purpose:     Handles the link create callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_link_create(H5VL_link_create_type_t create_type, void *obj,
+    const H5VL_loc_params_t *loc_params, hid_t lcpl_id, hid_t H5_ATTR_UNUSED lapl_id,
+    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
+{
+    H5P_genplist_t   *plist;                     /* Property list pointer */
+    herr_t           ret_value = SUCCEED;        /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    /* Get the plist structure */
+    if(NULL == (plist = (H5P_genplist_t *)H5I_object(lcpl_id)))
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID");
+
+    switch(create_type) {
+        case H5VL_LINK_CREATE_HARD:
+            {
+                H5G_loc_t    cur_loc;
+                H5G_loc_t    link_loc;
+                void         *cur_obj;
+                H5VL_loc_params_t cur_params;
+
+                if(H5P_get(plist, H5VL_PROP_LINK_TARGET, &cur_obj) < 0)
+                    HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get property value for current location id")
+                if(H5P_get(plist, H5VL_PROP_LINK_TARGET_LOC_PARAMS, &cur_params) < 0)
+                    HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get property value for current name")
+
+                if(NULL != cur_obj && H5G_loc_real(cur_obj, cur_params.obj_type, &cur_loc) < 0)
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+                if(NULL != obj && H5G_loc_real(obj, loc_params->obj_type, &link_loc) < 0)
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+                /* H5Lcreate_hard */
+                if(H5VL_OBJECT_BY_NAME == cur_params.type) {
+                    H5G_loc_t *cur_loc_p, *link_loc_p;
+
+                    /* Set up current & new location pointers */
+                    cur_loc_p = &cur_loc;
+                    link_loc_p = &link_loc;
+                    if(NULL == cur_obj)
+                        cur_loc_p = link_loc_p;
+                    else if(NULL == obj)
+                        link_loc_p = cur_loc_p;
+                    else if(cur_loc_p->oloc->file != link_loc_p->oloc->file)
+                        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "source and destination should be in the same file.")
+
+                    /* Create the link */
+                    if((ret_value = H5L_create_hard(cur_loc_p, cur_params.loc_data.loc_by_name.name, 
+                                                    link_loc_p, loc_params->loc_data.loc_by_name.name, lcpl_id)) < 0)
+                        HGOTO_ERROR(H5E_LINK, H5E_CANTINIT, FAIL, "unable to create link")
+                } /* end if */
+                else { /* H5Olink */
+                    /* Link to the object */
+                    if(H5L_link(&link_loc, loc_params->loc_data.loc_by_name.name, &cur_loc, lcpl_id) < 0)
+                        HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, FAIL, "unable to create link")
+                } /* end else */
+                break;
+            }
+
+        case H5VL_LINK_CREATE_SOFT:
+            {
+                char        *target_name;
+                H5G_loc_t   link_loc;               /* Group location for new link */
+
+                if(H5G_loc_real(obj, loc_params->obj_type, &link_loc) < 0)
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+                if(H5P_get(plist, H5VL_PROP_LINK_TARGET_NAME, &target_name) < 0)
+                    HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get property value for targe name")
+
+                /* Create the link */
+                if((ret_value = H5L_create_soft(target_name, &link_loc, loc_params->loc_data.loc_by_name.name, lcpl_id)) < 0)
+                    HGOTO_ERROR(H5E_LINK, H5E_CANTINIT, FAIL, "unable to create link")
+                break;
+            }
+
+        case H5VL_LINK_CREATE_UD:
+            {
+                H5G_loc_t   link_loc;               /* Group location for new link */
+                H5L_type_t link_type;
+                void *udata;
+                size_t udata_size;
+
+                if(H5G_loc_real(obj, loc_params->obj_type, &link_loc) < 0)
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+                if(H5P_get(plist, H5VL_PROP_LINK_TYPE, &link_type) < 0)
+                    HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get property value for link type")
+                if(H5P_get(plist, H5VL_PROP_LINK_UDATA, &udata) < 0)
+                    HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get property value for udata")
+                if(H5P_get(plist, H5VL_PROP_LINK_UDATA_SIZE, &udata_size) < 0)
+                    HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get property value for udata size")
+
+                /* Create link */
+                if(H5L__create_ud(&link_loc, loc_params->loc_data.loc_by_name.name, udata, udata_size, 
+                                 link_type, lcpl_id) < 0)
+                    HGOTO_ERROR(H5E_LINK, H5E_CANTINIT, FAIL, "unable to create link")
+                break;
+            }
+
+        default:
+            HGOTO_ERROR(H5E_LINK, H5E_CANTINIT, FAIL, "invalid link creation call")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_link_create() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_link_copy
+ *
+ * Purpose:     Handles the link copy callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_link_copy(void *src_obj, const H5VL_loc_params_t *loc_params1, 
+    void *dst_obj, const H5VL_loc_params_t *loc_params2, hid_t lcpl_id,
+    hid_t H5_ATTR_UNUSED lapl_id, hid_t H5_ATTR_UNUSED dxpl_id,
+    void H5_ATTR_UNUSED **req)
+{
+    H5G_loc_t   src_loc, *src_loc_p;
+    H5G_loc_t   dst_loc, *dst_loc_p;
+    herr_t      ret_value = SUCCEED;        /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    if(NULL != src_obj && H5G_loc_real(src_obj, loc_params1->obj_type, &src_loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+    if(NULL != dst_obj && H5G_loc_real(dst_obj, loc_params2->obj_type, &dst_loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+    /* Set up src & dst location pointers */
+    src_loc_p = &src_loc;
+    dst_loc_p = &dst_loc;
+    if(NULL == src_obj)
+        src_loc_p = dst_loc_p;
+    else if(NULL == dst_obj)
+        dst_loc_p = src_loc_p;
+
+    /* Copy the link */
+    if(H5L_move(src_loc_p, loc_params1->loc_data.loc_by_name.name, 
+                dst_loc_p, loc_params2->loc_data.loc_by_name.name, 
+                TRUE, lcpl_id) < 0)
+        HGOTO_ERROR(H5E_LINK, H5E_CANTCOPY, FAIL, "unable to copy link")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_link_copy() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_link_move
+ *
+ * Purpose:     Handles the link move callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_link_move(void *src_obj, const H5VL_loc_params_t *loc_params1, 
+    void *dst_obj, const H5VL_loc_params_t *loc_params2, hid_t lcpl_id,
+    hid_t H5_ATTR_UNUSED lapl_id, hid_t H5_ATTR_UNUSED dxpl_id,
+    void H5_ATTR_UNUSED **req)
+{
+    H5G_loc_t   src_loc, *src_loc_p;
+    H5G_loc_t   dst_loc, *dst_loc_p;
+    herr_t      ret_value = SUCCEED;        /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    if(NULL != src_obj && H5G_loc_real(src_obj, loc_params1->obj_type, &src_loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+    if(NULL != dst_obj && H5G_loc_real(dst_obj, loc_params2->obj_type, &dst_loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+    /* Set up src & dst location pointers */
+    src_loc_p = &src_loc;
+    dst_loc_p = &dst_loc;
+    if(NULL == src_obj)
+        src_loc_p = dst_loc_p;
+    else if(NULL == dst_obj)
+        dst_loc_p = src_loc_p;
+
+    /* Move the link */
+    if(H5L_move(src_loc_p, loc_params1->loc_data.loc_by_name.name, 
+                dst_loc_p, loc_params2->loc_data.loc_by_name.name, 
+                FALSE, lcpl_id) < 0)
+        HGOTO_ERROR(H5E_LINK, H5E_CANTMOVE, FAIL, "unable to move link")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_link_move() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_link_get
+ *
+ * Purpose:     Handles the link get callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_link_get(void *obj, const H5VL_loc_params_t *loc_params, H5VL_link_get_t get_type, 
+    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
+{
+    H5G_loc_t   loc;
+    herr_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+    switch(get_type) {
+        /* H5Lget_info/H5Lget_info_by_idx */
+        case H5VL_LINK_GET_INFO:
+            {
+                H5L_info_t *linfo  = HDva_arg(arguments, H5L_info_t *);
+
+                /* Get the link information */
+                if(loc_params->type == H5VL_OBJECT_BY_NAME) { /* H5Lget_info */
+                    if(H5L_get_info(&loc, loc_params->loc_data.loc_by_name.name, linfo) < 0)
+                        HGOTO_ERROR(H5E_LINK, H5E_NOTFOUND, FAIL, "unable to get link info")
+                } /* end if */
+                else if(loc_params->type == H5VL_OBJECT_BY_IDX) { /* H5Lget_info_by_idx */
+                    if(H5L_get_info_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, loc_params->loc_data.loc_by_idx.idx_type,
+                            loc_params->loc_data.loc_by_idx.order, loc_params->loc_data.loc_by_idx.n, linfo) < 0)
+                        HGOTO_ERROR(H5E_LINK, H5E_NOTFOUND, FAIL, "unable to get link info")
+                } /* end else-if */
+                else
+                    HGOTO_ERROR(H5E_LINK, H5E_NOTFOUND, FAIL, "unable to get link info")
+                break;
+            }
+
+        /* H5Lget_name_by_idx */
+        case H5VL_LINK_GET_NAME:
+            {
+                char       *name   = HDva_arg(arguments, char *);
+                size_t      size   = HDva_arg(arguments, size_t);
+                ssize_t    *ret    = HDva_arg(arguments, ssize_t *);
+
+                /* Get the link name */
+                if((*ret = H5L_get_name_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, loc_params->loc_data.loc_by_idx.idx_type,
+                            loc_params->loc_data.loc_by_idx.order, loc_params->loc_data.loc_by_idx.n, name, size)) < 0)
+                    HGOTO_ERROR(H5E_LINK, H5E_NOTFOUND, FAIL, "unable to get link info")
+
+                break;
+            }
+
+        /* H5Lget_val/H5Lget_val_by_idx */
+        case H5VL_LINK_GET_VAL:
+            {
+                void       *buf    = HDva_arg(arguments, void *);
+                size_t     size    = HDva_arg(arguments, size_t);
+
+                /* Get the link information */
+                if(loc_params->type == H5VL_OBJECT_BY_NAME) { /* H5Lget_val */
+                    if(H5L_get_val(&loc, loc_params->loc_data.loc_by_name.name, buf, size) < 0)
+                        HGOTO_ERROR(H5E_LINK, H5E_NOTFOUND, FAIL, "unable to get link value")
+                }
+                else if(loc_params->type == H5VL_OBJECT_BY_IDX) { /* H5Lget_val_by_idx */
+
+                    if(H5L_get_val_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, loc_params->loc_data.loc_by_idx.idx_type,
+                            loc_params->loc_data.loc_by_idx.order, loc_params->loc_data.loc_by_idx.n, buf, size) < 0)
+                        HGOTO_ERROR(H5E_LINK, H5E_NOTFOUND, FAIL, "unable to get link val")                    
+                }
+                else
+                    HGOTO_ERROR(H5E_LINK, H5E_NOTFOUND, FAIL, "unable to get link val")
+
+                break;
+            }
+
+        default:
+            HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't get this type of information from link")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_link_get() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_link_specific
+ *
+ * Purpose:     Handles the link specific callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_link_specific(void *obj, const H5VL_loc_params_t *loc_params, H5VL_link_specific_t specific_type, 
+    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
+{
+    herr_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    switch(specific_type) {
+        case H5VL_LINK_EXISTS:
+            {
+                htri_t *ret = HDva_arg(arguments, htri_t *);
+                H5G_loc_t loc;
+
+                if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+                /* Check for the existence of the link */
+                if((*ret = H5L_exists(&loc, loc_params->loc_data.loc_by_name.name)) < 0)
+                    HGOTO_ERROR(H5E_LINK, H5E_NOTFOUND, FAIL, "unable to specific link info")
+                break;
+            }
+
+        case H5VL_LINK_ITER:
+            {
+                H5G_loc_t loc;
+                hbool_t recursive       = (hbool_t)HDva_arg(arguments, unsigned);
+                H5_index_t idx_type     = (H5_index_t)HDva_arg(arguments, int); /* enum work-around */
+                H5_iter_order_t order   = (H5_iter_order_t)HDva_arg(arguments, int); /* enum work-around */
+                hsize_t *idx_p          = HDva_arg(arguments, hsize_t *);
+                H5L_iterate_t op        = HDva_arg(arguments, H5L_iterate_t);
+                void *op_data           = HDva_arg(arguments, void *);
+
+                /* Get the location */
+                if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+
+                /* Visit or iterate over the links */
+                if(loc_params->type == H5VL_OBJECT_BY_SELF) {
+                    if(recursive) {
+                        /* H5Lvisit */
+                        if((ret_value = H5G_visit(&loc, ".", idx_type, order, op, op_data)) < 0)
+                            HGOTO_ERROR(H5E_LINK, H5E_BADITER, FAIL, "link visitation failed")
+                    } /* end if */
+                    else {
+                        /* H5Literate */
+                        if((ret_value = H5L_iterate(&loc, ".", idx_type, order, idx_p, op, op_data)) < 0)
+                            HGOTO_ERROR(H5E_LINK, H5E_BADITER, FAIL, "error iterating over links")
+                    } /* end else */
+                } /* end if */
+                else if(loc_params->type == H5VL_OBJECT_BY_NAME) {
+                    if(recursive) {
+                        /* H5Lvisit_by_name */
+                        if((ret_value = H5G_visit(&loc, loc_params->loc_data.loc_by_name.name, idx_type, order, op, op_data)) < 0)
+                            HGOTO_ERROR(H5E_LINK, H5E_BADITER, FAIL, "link visitation failed")
+                    } /* end if */
+                    else {
+                        /* H5Literate_by_name */
+                        if((ret_value = H5L_iterate(&loc, loc_params->loc_data.loc_by_name.name, idx_type, order, idx_p, op, op_data)) < 0)
+                            HGOTO_ERROR(H5E_LINK, H5E_BADITER, FAIL, "error iterating over links")
+                    } /* end else */
+                } /* end else-if */
+                else
+                    HGOTO_ERROR(H5E_LINK, H5E_UNSUPPORTED, FAIL, "unknown link iterate params")
+
+                break;
+            }
+
+        case H5VL_LINK_DELETE:
+            {
+                H5G_loc_t loc;
+
+                if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+                /* Unlink */
+                if(loc_params->type == H5VL_OBJECT_BY_NAME) { /* H5Ldelete */
+                    if(H5L_delete(&loc, loc_params->loc_data.loc_by_name.name) < 0)
+                        HGOTO_ERROR(H5E_LINK, H5E_CANTDELETE, FAIL, "unable to delete link")
+                } /* end if */
+                else if(loc_params->type == H5VL_OBJECT_BY_IDX) { /* H5Ldelete_by_idx */
+                    if(H5L_delete_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, loc_params->loc_data.loc_by_idx.idx_type,
+                            loc_params->loc_data.loc_by_idx.order, loc_params->loc_data.loc_by_idx.n) < 0)
+                        HGOTO_ERROR(H5E_LINK, H5E_CANTDELETE, FAIL, "unable to delete link")
+                } /* end else-if */
+                else
+                    HGOTO_ERROR(H5E_LINK, H5E_CANTDELETE, FAIL, "unable to delete link")
+                break;
+            }
+
+        default:
+            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "invalid specific operation")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_link_specific() */
+
diff --git a/src/H5VLnative_object.c b/src/H5VLnative_object.c
new file mode 100644
index 0000000..0b1d73a
--- /dev/null
+++ b/src/H5VLnative_object.c
@@ -0,0 +1,482 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*
+ * Purpose:     Object callbacks for the native VOL connector
+ *
+ */
+
+#define H5O_FRIEND              /* Suppress error about including H5Opkg    */
+#define H5R_FRIEND              /* Suppress error about including H5Rpkg    */
+
+#include "H5private.h"          /* Generic Functions                        */
+#include "H5Eprivate.h"         /* Error handling                           */
+#include "H5Fprivate.h"         /* Files                                    */
+#include "H5Gprivate.h"         /* Groups                                   */
+#include "H5Iprivate.h"         /* IDs                                      */
+#include "H5Opkg.h"             /* Object headers                           */
+#include "H5Pprivate.h"         /* Property lists                           */
+#include "H5Rpkg.h"             /* References                               */
+#include "H5VLprivate.h"        /* Virtual Object Layer                     */
+
+#include "H5VLnative_private.h" /* Native VOL connector                     */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_object_open
+ *
+ * Purpose:     Handles the object open callback
+ *
+ * Return:      Success:    object pointer
+ *              Failure:    NULL
+ *
+ *-------------------------------------------------------------------------
+ */
+void *
+H5VL__native_object_open(void *obj, const H5VL_loc_params_t *loc_params, H5I_type_t *opened_type, 
+    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
+{
+    H5G_loc_t   loc;
+    void       *ret_value = NULL;
+
+    FUNC_ENTER_PACKAGE
+
+    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file or file object")
+
+    switch(loc_params->type) {
+        case H5VL_OBJECT_BY_NAME:
+            {
+                /* Open the object */
+                if(NULL == (ret_value = H5O_open_name(&loc, loc_params->loc_data.loc_by_name.name, opened_type)))
+                    HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, NULL, "unable to open object by name")
+                break;
+            }
+
+        case H5VL_OBJECT_BY_IDX:
+            {
+                /* Open the object */
+                if(NULL == (ret_value = H5O_open_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, loc_params->loc_data.loc_by_idx.idx_type,
+                        loc_params->loc_data.loc_by_idx.order, loc_params->loc_data.loc_by_idx.n, opened_type)))
+                    HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, NULL, "unable to open object by index")
+                break;
+            }
+
+        case H5VL_OBJECT_BY_ADDR:
+            {
+                /* Open the object */
+                if(NULL == (ret_value = H5O_open_by_addr(&loc, loc_params->loc_data.loc_by_addr.addr, opened_type)))
+                    HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, NULL, "unable to open object by address")
+                break;
+            }
+
+        case H5VL_OBJECT_BY_REF:
+            {
+                hid_t temp_id = H5I_INVALID_HID;
+                H5F_t *file = NULL;
+
+                /* Get the file pointer from the entry */
+                file = loc.oloc->file;
+
+                /* Create reference */
+                if((temp_id = H5R__dereference(file, loc_params->loc_data.loc_by_ref.lapl_id, 
+                                              loc_params->loc_data.loc_by_ref.ref_type, 
+                                              loc_params->loc_data.loc_by_ref._ref)) < 0)
+                    HGOTO_ERROR(H5E_REFERENCE, H5E_CANTOPENOBJ, NULL, "unable to dereference object")
+
+                *opened_type = H5I_get_type(temp_id);
+                if(NULL == (ret_value = H5I_remove(temp_id)))
+                    HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, NULL, "unable to open object")
+                break;
+            }
+
+        case H5VL_OBJECT_BY_SELF:
+        default:
+            HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, NULL, "unknown open parameters")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_object_open() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_object_copy
+ *
+ * Purpose:     Handles the object copy callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t 
+H5VL__native_object_copy(void *src_obj, const H5VL_loc_params_t *loc_params1, const char *src_name, 
+    void *dst_obj, const H5VL_loc_params_t *loc_params2, const char *dst_name, 
+    hid_t ocpypl_id, hid_t lcpl_id, hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req)
+{
+    H5G_loc_t   src_loc;                /* Source object group location */
+    H5G_loc_t   dst_loc;                /* Destination group location */
+    herr_t      ret_value = FAIL;
+    
+    FUNC_ENTER_PACKAGE
+
+    /* get location for objects */
+    if(H5G_loc_real(src_obj, loc_params1->obj_type, &src_loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+    if(H5G_loc_real(dst_obj, loc_params2->obj_type, &dst_loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+    /* Copy the object */
+    if((ret_value = H5O_copy(&src_loc, src_name, &dst_loc, dst_name, ocpypl_id, lcpl_id)) < 0)
+        HGOTO_ERROR(H5E_SYM, H5E_CANTCOPY, FAIL, "unable to copy object")    
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_object_copy() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_object_get
+ *
+ * Purpose:     Handles the object get callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_object_get(void *obj, const H5VL_loc_params_t *loc_params, H5VL_object_get_t get_type, 
+    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
+{
+    herr_t      ret_value = SUCCEED;    /* Return value */
+    H5G_loc_t   loc;                    /* Location of group */
+
+    FUNC_ENTER_PACKAGE
+
+    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+    switch(get_type) {
+        /* H5Rget_region */
+        case H5VL_REF_GET_REGION:
+            {
+                hid_t       *ret                    =  HDva_arg(arguments, hid_t *);
+                H5R_type_t  H5_ATTR_UNUSED ref_type =  (H5R_type_t)HDva_arg(arguments, int); /* enum work-around */
+                void        *ref                    =  HDva_arg(arguments, void *);
+                H5S_t       *space = NULL;    /* Dataspace object */
+
+                /* Get the dataspace with the correct region selected */
+                if((space = H5R__get_region(loc.oloc->file, ref)) == NULL)
+                    HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, FAIL, "unable to retrieve region")
+
+                /* Atomize */
+                if((*ret = H5I_register(H5I_DATASPACE, space, TRUE)) < 0)
+                    HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register dataspace atom")
+
+                break;
+            }
+
+        /* H5Rget_obj_type1/2 */
+        case H5VL_REF_GET_TYPE:
+            {
+                H5O_type_t  *obj_type  =  HDva_arg(arguments, H5O_type_t *);
+                H5R_type_t  ref_type   =  (H5R_type_t)HDva_arg(arguments, int); /* enum work-around */
+                void        *ref       =  HDva_arg(arguments, void *);
+
+                /* Get the object information */
+                if(H5R__get_obj_type(loc.oloc->file, ref_type, ref, obj_type) < 0)
+                    HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, FAIL, "unable to determine object type")
+                break;
+            }
+
+        /* H5Rget_name */
+        case H5VL_REF_GET_NAME:
+            {
+                ssize_t     *ret       = HDva_arg(arguments, ssize_t *);
+                char        *name      = HDva_arg(arguments, char *);
+                size_t      size       = HDva_arg(arguments, size_t);
+                H5R_type_t  ref_type   = (H5R_type_t)HDva_arg(arguments, int); /* enum work-around */
+                void        *ref       = HDva_arg(arguments, void *);
+
+                /* Get name */
+                if((*ret = H5R__get_name(loc.oloc->file, ref_type, ref, name, size)) < 0)
+                    HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, FAIL, "unable to determine object path")
+                break;
+            }
+
+        /* H5Iget_name */
+        case H5VL_ID_GET_NAME:
+            {
+                ssize_t *ret = HDva_arg(arguments, ssize_t *);
+                char *name = HDva_arg(arguments, char *);
+                size_t size = HDva_arg(arguments, size_t);
+
+                /* Retrieve object's name */
+                if((*ret = H5G_get_name(&loc, name, size, NULL)) < 0)
+                    HGOTO_ERROR(H5E_ATOM, H5E_CANTGET, FAIL, "can't retrieve object name")
+
+                break;
+            }
+
+        default:
+            HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't get this type of information from object")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_object_get() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_object_specific
+ *
+ * Purpose:     Handles the object specific callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_object_specific(void *obj, const H5VL_loc_params_t *loc_params, H5VL_object_specific_t specific_type, 
+    hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR_UNUSED **req, va_list arguments)
+{
+    H5G_loc_t    loc;
+    herr_t       ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+    switch(specific_type) {
+        /* H5Oincr_refcount / H5Odecr_refcount */
+        case H5VL_OBJECT_CHANGE_REF_COUNT:
+            {
+                int update_ref  = HDva_arg(arguments, int);
+                H5O_loc_t  *oloc = loc.oloc;
+
+                if(H5O_link(oloc, update_ref) < 0)
+                    HGOTO_ERROR(H5E_OHDR, H5E_LINKCOUNT, FAIL, "modifying object link count failed")
+
+                break;
+            }
+
+        /* H5Oexists_by_name */
+        case H5VL_OBJECT_EXISTS:
+            {
+                htri_t *ret = HDva_arg(arguments, htri_t *);
+
+                if(loc_params->type == H5VL_OBJECT_BY_NAME) {
+                    /* Check if the object exists */
+                    if((*ret = H5G_loc_exists(&loc, loc_params->loc_data.loc_by_name.name)) < 0)
+                        HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "unable to determine if '%s' exists", loc_params->loc_data.loc_by_name.name)
+                } /* end if */
+                else
+                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown object exists parameters")
+                break;
+            }
+
+        case H5VL_OBJECT_VISIT:
+            {
+                H5_index_t idx_type     = (H5_index_t)HDva_arg(arguments, int); /* enum work-around */
+                H5_iter_order_t order   = (H5_iter_order_t)HDva_arg(arguments, int); /* enum work-around */
+                H5O_iterate_t op        = HDva_arg(arguments, H5O_iterate_t);
+                void *op_data           = HDva_arg(arguments, void *);
+                unsigned fields         = HDva_arg(arguments, unsigned);
+
+                /* Call internal object visitation routine */
+                if(loc_params->type == H5VL_OBJECT_BY_SELF) {
+                    /* H5Ovisit */
+                    if((ret_value = H5O__visit(&loc, ".", idx_type, order, op, op_data, fields)) < 0)
+                        HGOTO_ERROR(H5E_OHDR, H5E_BADITER, FAIL, "object visitation failed")
+                } /* end if */
+                else if(loc_params->type == H5VL_OBJECT_BY_NAME) {
+                    /* H5Ovisit_by_name */
+                    if((ret_value = H5O__visit(&loc, loc_params->loc_data.loc_by_name.name, idx_type, order, op, op_data, fields)) < 0)
+                        HGOTO_ERROR(H5E_OHDR, H5E_BADITER, FAIL, "object visitation failed")
+                } /* end else-if */
+                else
+                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown object visit params");
+                break;
+            }
+
+        case H5VL_OBJECT_FLUSH:
+            {
+                hid_t   oid     = HDva_arg(arguments, hid_t);
+
+                /* Flush the object's metadata */
+                if(H5O_flush(loc.oloc, oid) < 0)
+                    HGOTO_ERROR(H5E_OHDR, H5E_CANTFLUSH, FAIL, "unable to flush object")
+
+                break;
+            }
+
+        case H5VL_OBJECT_REFRESH:
+            {
+                hid_t                   oid         = HDva_arg(arguments, hid_t);
+                H5O_loc_t              *oloc        = loc.oloc;
+
+                /* Refresh the metadata */
+                if(H5O_refresh_metadata(oid, *oloc) < 0)
+                    HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, FAIL, "unable to refresh object")
+
+                break;
+            }
+
+        case H5VL_REF_CREATE:
+            {
+                void        *ref      = HDva_arg(arguments, void *);
+                const char  *name     = HDva_arg(arguments, char *);
+                H5R_type_t  ref_type  = (H5R_type_t)HDva_arg(arguments, int); /* enum work-around */
+                hid_t       space_id  = HDva_arg(arguments, hid_t);
+                H5S_t       *space = NULL;   /* Pointer to dataspace containing region */
+                
+                if(space_id != (-1) && (NULL == (space = (H5S_t *)H5I_object_verify(space_id, H5I_DATASPACE))))
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataspace")
+
+                /* Create reference */
+                if(H5R__create(ref, &loc, name, ref_type, space) < 0)
+                    HGOTO_ERROR(H5E_REFERENCE, H5E_CANTCREATE, FAIL, "unable to create reference")
+
+                break;
+            }
+
+        default:
+            HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't recognize this operation type")
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_object_specific() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5VL__native_object_optional
+ *
+ * Purpose:     Handles the object optional callback
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5VL__native_object_optional(void *obj, hid_t H5_ATTR_UNUSED dxpl_id,
+    void H5_ATTR_UNUSED **req, va_list arguments)
+{
+    H5VL_native_object_optional_t optional_type = HDva_arg(arguments, H5VL_native_object_optional_t);
+    H5VL_loc_params_t *loc_params = HDva_arg(arguments, H5VL_loc_params_t *);
+    H5G_loc_t   loc;                    /* Location of group */
+    herr_t       ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
+
+    switch(optional_type) {
+        /* H5Oget_info / H5Oget_info_by_name / H5Oget_info_by_idx */
+        case H5VL_NATIVE_OBJECT_GET_INFO:
+            {
+                H5O_info_t  *obj_info = HDva_arg(arguments, H5O_info_t *);
+                unsigned fields         = HDva_arg(arguments, unsigned);
+
+                if(loc_params->type == H5VL_OBJECT_BY_SELF) { /* H5Oget_info */
+                    /* Retrieve the object's information */
+                    if(H5G_loc_info(&loc, ".", obj_info, fields) < 0)
+                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
+                } /* end if */
+                else if(loc_params->type == H5VL_OBJECT_BY_NAME) { /* H5Oget_info_by_name */
+                    /* Retrieve the object's information */
+                    if(H5G_loc_info(&loc, loc_params->loc_data.loc_by_name.name, obj_info, fields) < 0)
+                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
+                } /* end else-if */
+                else if(loc_params->type == H5VL_OBJECT_BY_IDX) { /* H5Oget_info_by_idx */
+                    H5G_loc_t   obj_loc;                /* Location used to open group */
+                    H5G_name_t  obj_path;               /* Opened object group hier. path */
+                    H5O_loc_t   obj_oloc;               /* Opened object object location */
+
+                    /* Set up opened group location to fill in */
+                    obj_loc.oloc = &obj_oloc;
+                    obj_loc.path = &obj_path;
+                    H5G_loc_reset(&obj_loc);
+
+                    /* Find the object's location, according to the order in the index */
+                    if(H5G_loc_find_by_idx(&loc, loc_params->loc_data.loc_by_idx.name, 
+                                           loc_params->loc_data.loc_by_idx.idx_type, 
+                                           loc_params->loc_data.loc_by_idx.order, 
+                                           loc_params->loc_data.loc_by_idx.n, &obj_loc/*out*/) < 0)
+                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "group not found")
+
+                    /* Retrieve the object's information */
+                    if(H5O_get_info(obj_loc.oloc, obj_info, fields) < 0) {
+                        H5G_loc_free(&obj_loc);
+                        HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "can't retrieve object info")
+                    } /* end if */
+
+                    /* Release the object location */
+                    if(H5G_loc_free(&obj_loc) < 0)
+                        HGOTO_ERROR(H5E_OHDR, H5E_CANTRELEASE, FAIL, "can't free location")
+                } /* end else-if */
+                else
+                    HGOTO_ERROR(H5E_OHDR, H5E_UNSUPPORTED, FAIL, "unknown get info parameters")
+                break;
+            }
+
+        /* H5Oget_comment / H5Oget_comment_by_name */
+        case H5VL_NATIVE_OBJECT_GET_COMMENT:
+            {
+                char     *comment =  HDva_arg(arguments, char *);
+                size_t   bufsize  =  HDva_arg(arguments, size_t);
+                ssize_t  *ret     =  HDva_arg(arguments, ssize_t *);
+
+                /* Retrieve the object's comment */
+                if(loc_params->type == H5VL_OBJECT_BY_SELF) { /* H5Oget_comment */
+                    if((*ret = H5G_loc_get_comment(&loc, ".", comment/*out*/, bufsize)) < 0)
+                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
+                } /* end if */
+                else if(loc_params->type == H5VL_OBJECT_BY_NAME) { /* H5Oget_comment_by_name */
+                    if((*ret = H5G_loc_get_comment(&loc, loc_params->loc_data.loc_by_name.name, comment/*out*/, bufsize)) < 0)
+                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
+                } /* end else-if */
+                else
+                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown set_coment parameters")
+                break;
+            }
+
+        /* H5Oset_comment */
+        case H5VL_NATIVE_OBJECT_SET_COMMENT:
+            {
+                const char    *comment  = HDva_arg(arguments, char *);
+
+                if(loc_params->type == H5VL_OBJECT_BY_SELF) { /* H5Oset_comment */
+                    /* (Re)set the object's comment */
+                    if(H5G_loc_set_comment(&loc, ".", comment) < 0)
+                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
+                } /* end if */
+                else if(loc_params->type == H5VL_OBJECT_BY_NAME) { /* H5Oset_comment_by_name */
+                    /* (Re)set the object's comment */
+                    if(H5G_loc_set_comment(&loc, loc_params->loc_data.loc_by_name.name, comment) < 0)
+                        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
+                } /* end else-if */
+                else
+                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown set_coment parameters")
+                break;
+            }
+
+        default:
+            HGOTO_ERROR(H5E_VOL, H5E_CANTGET, FAIL, "can't perform this operation on object");       
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__native_object_optional() */
+
diff --git a/src/H5VLnative_private.h b/src/H5VLnative_private.h
new file mode 100644
index 0000000..1bf4da2
--- /dev/null
+++ b/src/H5VLnative_private.h
@@ -0,0 +1,88 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*
+ * Purpose:	The private header file for the native VOL connector.
+ */
+
+#ifndef _H5VLnative_private_H
+#define _H5VLnative_private_H
+
+#include "H5VLnative.h"             /* Native VOL connector                 */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Atrribute callbacks */
+H5_DLL void *H5VL__native_attr_create(void *obj, const H5VL_loc_params_t *loc_params, const char *attr_name, hid_t acpl_id, hid_t aapl_id, hid_t dxpl_id, void **req);
+void *H5VL__native_attr_open(void *obj, const H5VL_loc_params_t *loc_params, const char *attr_name, hid_t aapl_id, hid_t dxpl_id, void **req);
+H5_DLL herr_t H5VL__native_attr_read(void *attr, hid_t dtype_id, void *buf, hid_t dxpl_id, void **req);
+H5_DLL herr_t H5VL__native_attr_write(void *attr, hid_t dtype_id, const void *buf, hid_t dxpl_id, void **req);
+H5_DLL herr_t H5VL__native_attr_get(void *obj, H5VL_attr_get_t get_type, hid_t dxpl_id, void **req, va_list arguments);
+H5_DLL herr_t H5VL__native_attr_specific(void *obj, const H5VL_loc_params_t *loc_params, H5VL_attr_specific_t specific_type, hid_t dxpl_id, void **req, va_list arguments);
+H5_DLL herr_t H5VL__native_attr_optional(void *obj, hid_t dxpl_id, void **req, va_list arguments);
+H5_DLL herr_t H5VL__native_attr_close(void *attr, hid_t dxpl_id, void **req);
+
+/* Dataset callbacks */
+H5_DLL void *H5VL__native_dataset_create(void *obj, const H5VL_loc_params_t *loc_params, const char *name, hid_t dcpl_id, hid_t dapl_id, hid_t dxpl_id, void **req);
+H5_DLL void *H5VL__native_dataset_open(void *obj, const H5VL_loc_params_t *loc_params, const char *name, hid_t dapl_id, hid_t dxpl_id, void **req);
+H5_DLL herr_t H5VL__native_dataset_read(void *dset, hid_t mem_type_id, hid_t mem_space_id, hid_t file_space_id, hid_t plist_id, void *buf, void **req);
+H5_DLL herr_t H5VL__native_dataset_write(void *dset, hid_t mem_type_id, hid_t mem_space_id, hid_t file_space_id, hid_t plist_id, const void *buf, void **req);
+H5_DLL herr_t H5VL__native_dataset_get(void *dset, H5VL_dataset_get_t get_type, hid_t dxpl_id, void **req, va_list arguments);
+H5_DLL herr_t H5VL__native_dataset_specific(void *dset, H5VL_dataset_specific_t specific_type, hid_t dxpl_id, void **req, va_list arguments);
+H5_DLL herr_t H5VL__native_dataset_optional(void *dset, hid_t dxpl_id, void **req, va_list arguments);
+H5_DLL herr_t H5VL__native_dataset_close(void *dset, hid_t dxpl_id, void **req);
+
+/* File callbacks */
+H5_DLL void *H5VL__native_file_create(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id, hid_t dxpl_id, void **req);
+H5_DLL void *H5VL__native_file_open(const char *name, unsigned flags, hid_t fapl_id, hid_t dxpl_id, void **req);
+H5_DLL herr_t H5VL__native_file_get(void *file, H5VL_file_get_t get_type, hid_t dxpl_id, void **req, va_list arguments);
+H5_DLL herr_t H5VL__native_file_specific(void *file, H5VL_file_specific_t specific_type, hid_t dxpl_id, void **req, va_list arguments);
+H5_DLL herr_t H5VL__native_file_optional(void *file, hid_t dxpl_id, void **req, va_list arguments);
+H5_DLL herr_t H5VL__native_file_close(void *file, hid_t dxpl_id, void **req);
+
+/* Group callbacks */
+H5_DLL void *H5VL__native_group_create(void *obj, const H5VL_loc_params_t *loc_params, const char *name, hid_t gcpl_id, hid_t gapl_id, hid_t dxpl_id, void **req);
+H5_DLL void *H5VL__native_group_open(void *obj, const H5VL_loc_params_t *loc_params, const char *name, hid_t gapl_id, hid_t dxpl_id, void **req);
+H5_DLL herr_t H5VL__native_group_get(void *obj, H5VL_group_get_t get_type, hid_t dxpl_id, void **req, va_list arguments);
+H5_DLL herr_t H5VL__native_group_specific(void *obj, H5VL_group_specific_t specific_type, hid_t dxpl_id, void **req, va_list arguments);
+H5_DLL herr_t H5VL__native_group_optional(void *obj, hid_t dxpl_id, void **req, va_list arguments);
+H5_DLL herr_t H5VL__native_group_close(void *grp, hid_t dxpl_id, void **req);
+
+/* Link callbacks */
+H5_DLL herr_t H5VL__native_link_create(H5VL_link_create_type_t create_type, void *obj, const H5VL_loc_params_t *loc_params, hid_t lcpl_id, hid_t lapl_id, hid_t dxpl_id, void **req);
+H5_DLL herr_t H5VL__native_link_copy(void *src_obj, const H5VL_loc_params_t *loc_params1, void *dst_obj, const H5VL_loc_params_t *loc_params2, hid_t lcpl_id, hid_t lapl_id, hid_t dxpl_id, void **req);
+H5_DLL herr_t H5VL__native_link_move(void *src_obj, const H5VL_loc_params_t *loc_params1, void *dst_obj, const H5VL_loc_params_t *loc_params2, hid_t lcpl_id, hid_t lapl_id, hid_t dxpl_id, void **req);
+H5_DLL herr_t H5VL__native_link_get(void *obj, const H5VL_loc_params_t *loc_params, H5VL_link_get_t get_type, hid_t dxpl_id, void **req, va_list arguments);
+H5_DLL herr_t H5VL__native_link_specific(void *obj, const H5VL_loc_params_t *loc_params, H5VL_link_specific_t specific_type, hid_t dxpl_id, void **req, va_list arguments);
+
+/* Object callbacks */
+H5_DLL void *H5VL__native_object_open(void *obj, const H5VL_loc_params_t *loc_params, H5I_type_t *opened_type, hid_t dxpl_id, void **req);
+H5_DLL herr_t H5VL__native_object_copy(void *src_obj, const H5VL_loc_params_t *loc_params1, const char *src_name, void *dst_obj, const H5VL_loc_params_t *loc_params2, const char *dst_name, hid_t ocpypl_id, hid_t lcpl_id, hid_t dxpl_id, void **req);
+H5_DLL herr_t H5VL__native_object_get(void *obj, const H5VL_loc_params_t *loc_params, H5VL_object_get_t get_type, hid_t dxpl_id, void **req, va_list arguments);
+H5_DLL herr_t H5VL__native_object_specific(void *obj, const H5VL_loc_params_t *loc_params, H5VL_object_specific_t specific_type, hid_t dxpl_id, void **req, va_list arguments);
+H5_DLL herr_t H5VL__native_object_optional(void *obj, hid_t dxpl_id, void **req, va_list arguments);
+
+/* Datatype callbacks */
+H5_DLL void *H5VL__native_datatype_commit(void *obj, const H5VL_loc_params_t *loc_params, const char *name, hid_t type_id, hid_t lcpl_id, hid_t tcpl_id, hid_t tapl_id, hid_t dxpl_id, void **req);
+H5_DLL void *H5VL__native_datatype_open(void *obj, const H5VL_loc_params_t *loc_params, const char *name, hid_t tapl_id, hid_t dxpl_id, void **req);
+H5_DLL herr_t H5VL__native_datatype_get(void *dt, H5VL_datatype_get_t get_type, hid_t dxpl_id, void **req, va_list arguments);
+H5_DLL herr_t H5VL__native_datatype_specific(void *dt, H5VL_datatype_specific_t specific_type, hid_t dxpl_id, void **req, va_list arguments);
+H5_DLL herr_t H5VL__native_datatype_close(void *dt, hid_t dxpl_id, void **req);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _H5VLnative_private_H */
+
diff --git a/src/H5VLpassthru.c b/src/H5VLpassthru.c
index 49102d7..8b83e2e 100644
--- a/src/H5VLpassthru.c
+++ b/src/H5VLpassthru.c
@@ -1636,7 +1636,7 @@ H5VL_pass_through_file_specific(void *file, H5VL_file_specific_t specific_type,
         hid_t plist_id;
 
         /* Retrieve parameters for 'mount' operation, so we can unwrap the child file */
-        loc_type = va_arg(arguments, H5I_type_t);
+        loc_type = (H5I_type_t)va_arg(arguments, int); /* enum work-around */
         name = va_arg(arguments, const char *);
         child_file = (H5VL_pass_through_t *)va_arg(arguments, void *);
         plist_id = va_arg(arguments, hid_t);
@@ -1645,7 +1645,7 @@ H5VL_pass_through_file_specific(void *file, H5VL_file_specific_t specific_type,
         under_vol_id = o->under_vol_id;
 
         /* Re-issue 'file specific' call, using the unwrapped pieces */
-        ret_value = H5VL_pass_through_file_specific_reissue(o->under_object, o->under_vol_id, specific_type, dxpl_id, req, loc_type, name, child_file->under_object, plist_id);
+        ret_value = H5VL_pass_through_file_specific_reissue(o->under_object, o->under_vol_id, specific_type, dxpl_id, req, (int)loc_type, name, child_file->under_object, plist_id);
     } /* end if */
     else if(specific_type == H5VL_FILE_IS_ACCESSIBLE) {
         H5VL_pass_through_info_t *info;
diff --git a/src/H5VLpublic.h b/src/H5VLpublic.h
index 22cf12b..5de36c8 100644
--- a/src/H5VLpublic.h
+++ b/src/H5VLpublic.h
@@ -115,7 +115,7 @@ typedef enum H5VL_file_get_t {
     H5VL_FILE_GET_INTENT,	            /* file intent           		*/
     H5VL_FILE_GET_NAME,	                    /* file name             		*/
     H5VL_FILE_GET_OBJ_COUNT,	            /* object count in file	       	*/
-    H5VL_FILE_GET_OBJ_IDS 	            /* object ids in file     		*/
+    H5VL_FILE_GET_OBJ_IDS	            /* object ids in file     		*/
 } H5VL_file_get_t;
 
 /* types for file SPECIFIC callback */
diff --git a/src/H5err.txt b/src/H5err.txt
index 3965242..93a3abd 100644
--- a/src/H5err.txt
+++ b/src/H5err.txt
@@ -181,7 +181,7 @@ MINOR, CACHE, H5E_CANTRESIZE, Unable to resize a metadata cache entry
 MINOR, CACHE, H5E_CANTDEPEND, Unable to create a flush dependency
 MINOR, CACHE, H5E_CANTUNDEPEND, Unable to destroy a flush dependency
 MINOR, CACHE, H5E_CANTNOTIFY, Unable to notify object about action
-MINOR, CACHE, H5E_LOGFAIL, Failure in the cache logging framework
+MINOR, CACHE, H5E_LOGGING, Failure in the cache logging framework
 MINOR, CACHE, H5E_CANTCORK, Unable to cork an object
 MINOR, CACHE, H5E_CANTUNCORK, Unable to uncork an object
 
diff --git a/src/Makefile.am b/src/Makefile.am
index 69b51b2..5532655 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -40,12 +40,12 @@ DISTCLEANFILES=H5pubconf.h
 # library sources
 libhdf5_la_SOURCES= H5.c H5checksum.c H5dbg.c H5system.c H5timer.c H5trace.c \
         H5A.c H5Abtree2.c H5Adense.c H5Adeprec.c H5Aint.c H5Atest.c \
-        H5AC.c H5ACdbg.c H5AClog.c H5ACproxy_entry.c \
+        H5AC.c H5ACdbg.c H5ACproxy_entry.c \
         H5B.c H5Bcache.c H5Bdbg.c \
         H5B2.c H5B2cache.c H5B2dbg.c H5B2hdr.c H5B2int.c H5B2internal.c \
         H5B2leaf.c H5B2stat.c H5B2test.c \
-        H5C.c H5Cdbg.c H5Cepoch.c H5Cimage.c H5Clog.c H5Cprefetched.c \
-        H5Cquery.c H5Ctag.c H5Ctest.c \
+        H5C.c H5Cdbg.c H5Cepoch.c H5Cimage.c H5Clog.c H5Clog_json.c H5Clog_trace.c \
+        H5Cprefetched.c H5Cquery.c H5Ctag.c H5Ctest.c \
         H5CS.c \
         H5CX.c \
         H5D.c H5Dbtree.c H5Dbtree2.c H5Dchunk.c H5Dcompact.c H5Dcontig.c H5Ddbg.c \
@@ -114,7 +114,10 @@ libhdf5_la_SOURCES= H5.c H5checksum.c H5dbg.c H5system.c H5timer.c H5trace.c \
         H5Topaque.c \
         H5Torder.c \
         H5Tpad.c H5Tprecis.c H5Tstrpad.c H5Tvisit.c H5Tvlen.c H5TS.c \
-        H5VL.c H5VLcallback.c H5VLint.c H5VLnative.c H5VLpassthru.c \
+        H5VL.c H5VLcallback.c H5VLint.c H5VLnative.c \
+		H5VLnative_attr.c H5VLnative_dataset.c H5VLnative_datatype.c \
+		H5VLnative_file.c H5VLnative_group.c H5VLnative_link.c H5VLnative_object.c \
+		H5VLpassthru.c \
         H5VM.c H5WB.c H5Z.c  \
         H5Zdeflate.c H5Zfletcher32.c H5Znbit.c H5Zshuffle.c \
         H5Zscaleoffset.c H5Zszip.c H5Ztrans.c
diff --git a/src/libhdf5.settings.in b/src/libhdf5.settings.in
index 531cd00..9d0e29f 100644
--- a/src/libhdf5.settings.in
+++ b/src/libhdf5.settings.in
@@ -82,7 +82,6 @@ Parallel Filtered Dataset Writes: @PARALLEL_FILTERED_WRITES@
                      API tracing: @TRACE_API@
             Using memory checker: @USINGMEMCHECKER@
  Memory allocation sanity checks: @MEMORYALLOCSANITYCHECK@
-             Metadata trace file: @METADATATRACEFILE@
           Function stack tracing: @CODESTACK@
        Strict file format checks: @STRICT_FORMAT_CHECKS@
     Optimization instrumentation: @INSTRUMENT_LIBRARY@
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index ed6bacc..69afb85 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -133,7 +133,7 @@ if (BUILD_SHARED_LIBS)
   # Define VOL Plugin Test Sources
   #-----------------------------------------------------------------------------
   set (VOL_PLUGIN_LIBS
-      echo_vol
+      null_vol_connector
   )
 
   foreach (vol_lib ${VOL_PLUGIN_LIBS})
diff --git a/test/CMakeTests.cmake b/test/CMakeTests.cmake
index 1c26def..9816543 100644
--- a/test/CMakeTests.cmake
+++ b/test/CMakeTests.cmake
@@ -359,6 +359,9 @@ set (test_CLEANFILES
     lheap.h5
     fheap.h5
     ohdr.h5
+    ohdr_min_a.h5
+    ohdr_min_b.h5
+    min_dset_ohdr_testfile.h5
     stab.h5
     extern_*.h5
     extern_*.raw
@@ -1127,6 +1130,16 @@ endif ()
 
 ##############################################################################
 ##############################################################################
+###                         V O L   T E S T S                              ###
+##############################################################################
+##############################################################################
+
+if (HDF5_TEST_VOL)
+  include (CMakeVOLTests.cmake)
+endif ()
+
+##############################################################################
+##############################################################################
 ###           T H E   G E N E R A T O R S                                  ###
 ##############################################################################
 ##############################################################################
diff --git a/test/CMakeVOLTests.cmake b/test/CMakeVOLTests.cmake
new file mode 100644
index 0000000..39fa2a6
--- /dev/null
+++ b/test/CMakeVOLTests.cmake
@@ -0,0 +1,322 @@
+
+# Copyright by The HDF Group.
+# All rights reserved.
+#
+# This file is part of HDF5.  The full HDF5 copyright notice, including
+# terms governing use, modification, and redistribution, is contained in
+# the COPYING file, which can be found at the root of the source code
+# distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.
+# If you do not have access to either file, you may request a copy from
+# help@hdfgroup.org.
+#
+
+##############################################################################
+##############################################################################
+###           T E S T I N G                                                ###
+##############################################################################
+##############################################################################
+# included from CMakeTests.cmake
+
+set (VOL_LIST
+    vol_native
+    vol_pass_through1
+    vol_pass_through2
+)
+
+set (vol_native native)
+set (vol_pass_through1 "pass_through under_vol=0\;under_info={}")
+set (vol_pass_through2 "pass_through under_vol=505\;under_info={under_vol=0\;under_info={}}")
+
+foreach (voltest ${VOL_LIST})
+  file (MAKE_DIRECTORY "${PROJECT_BINARY_DIR}/${voltest}")
+  file (MAKE_DIRECTORY "${PROJECT_BINARY_DIR}/${voltest}/testfiles")
+  file (MAKE_DIRECTORY "${PROJECT_BINARY_DIR}/${voltest}/testfiles/plist_files")
+  if (BUILD_SHARED_LIBS)
+    file (MAKE_DIRECTORY "${PROJECT_BINARY_DIR}/${voltest}-shared")
+    file (MAKE_DIRECTORY "${PROJECT_BINARY_DIR}/${voltest}-shared/testfiles")
+    file (MAKE_DIRECTORY "${PROJECT_BINARY_DIR}/${voltest}-shared/testfiles/plist_files")
+  endif ()
+endforeach ()
+
+foreach (voltest ${VOL_LIST})
+  foreach (h5_tfile ${HDF5_TEST_FILES})
+    HDFTEST_COPY_FILE("${HDF5_TOOLS_DIR}/testfiles/${h5_tfile}" "${PROJECT_BINARY_DIR}/${voltest}/${h5_tfile}" "HDF5_VOLTEST_LIB_files")
+    if (BUILD_SHARED_LIBS)
+      HDFTEST_COPY_FILE("${HDF5_TOOLS_DIR}/testfiles/${h5_tfile}" "${PROJECT_BINARY_DIR}/${voltest}-shared/${h5_tfile}" "HDF5_VOLTEST_LIBSH_files")
+    endif ()
+  endforeach ()
+endforeach ()
+
+foreach (voltest ${VOL_LIST})
+  foreach (ref_file ${HDF5_REFERENCE_FILES})
+    HDFTEST_COPY_FILE("${HDF5_TEST_SOURCE_DIR}/testfiles/${ref_file}" "${PROJECT_BINARY_DIR}/${voltest}/${ref_file}" "HDF5_VOLTEST_LIB_files")
+    if (BUILD_SHARED_LIBS)
+      HDFTEST_COPY_FILE("${HDF5_TEST_SOURCE_DIR}/testfiles/${ref_file}" "${PROJECT_BINARY_DIR}/${voltest}-shared/${ref_file}" "HDF5_VOLTEST_LIBSH_files")
+    endif ()
+  endforeach ()
+endforeach ()
+
+foreach (voltest ${VOL_LIST})
+  foreach (h5_file ${HDF5_REFERENCE_TEST_FILES})
+    HDFTEST_COPY_FILE("${HDF5_TEST_SOURCE_DIR}/${h5_file}" "${HDF5_TEST_BINARY_DIR}/${voltest}/${h5_file}" "HDF5_VOLTEST_LIB_files")
+    if (BUILD_SHARED_LIBS)
+      HDFTEST_COPY_FILE("${HDF5_TEST_SOURCE_DIR}/${h5_file}" "${HDF5_TEST_BINARY_DIR}/${voltest}-shared/${h5_file}" "HDF5_VOLTEST_LIBSH_files")
+    endif ()
+  endforeach ()
+endforeach ()
+
+foreach (voltest ${VOL_LIST})
+  foreach (plistfile ${HDF5_REFERENCE_PLIST_FILES})
+    HDFTEST_COPY_FILE("${HDF5_TEST_SOURCE_DIR}/testfiles/plist_files/${plistfile}" "${PROJECT_BINARY_DIR}/${voltest}/testfiles/plist_files/${plistfile}" "HDF5_VOLTEST_LIB_files")
+    HDFTEST_COPY_FILE("${HDF5_TEST_SOURCE_DIR}/testfiles/plist_files/def_${plistfile}" "${PROJECT_BINARY_DIR}/${voltest}/testfiles/plist_files/def_${plistfile}" "HDF5_VOLTEST_LIB_files")
+    if (BUILD_SHARED_LIBS)
+      HDFTEST_COPY_FILE("${HDF5_TEST_SOURCE_DIR}/testfiles/plist_files/${plistfile}" "${PROJECT_BINARY_DIR}/${voltest}-shared/testfiles/plist_files/${plistfile}" "HDF5_VOLTEST_LIBSH_files")
+      HDFTEST_COPY_FILE("${HDF5_TEST_SOURCE_DIR}/testfiles/plist_files/def_${plistfile}" "${PROJECT_BINARY_DIR}/${voltest}-shared/testfiles/plist_files/def_${plistfile}" "HDF5_VOLTEST_LIBSH_files")
+    endif ()
+  endforeach ()
+endforeach ()
+
+add_custom_target(HDF5_VOLTEST_LIB_files ALL COMMENT "Copying files needed by HDF5_VOLTEST_LIB tests" DEPENDS ${HDF5_VOLTEST_LIB_files_list})
+if (BUILD_SHARED_LIBS)
+  add_custom_target(HDF5_VOLTEST_LIBSH_files ALL COMMENT "Copying files needed by HDF5_VOLTEST_LIBSH tests" DEPENDS ${HDF5_VOLTEST_LIBSH_files_list})
+endif ()
+
+##############################################################################
+##############################################################################
+###                         V O L   T E S T S                              ###
+##############################################################################
+##############################################################################
+
+  set (H5_VOL_SKIP_TESTS
+      cache
+      accum
+      fheap
+      big
+      vol
+      error_test
+      err_compat
+      tcheck_version
+      testmeta
+      links_env
+  )
+  if (NOT CYGWIN)
+    list (REMOVE_ITEM H5_VOL_SKIP_TESTS big cache)
+  endif ()
+
+  # Windows only macro
+  macro (CHECK_VOL_TEST voltest volname volinfo resultcode)
+    if ("${voltest}" STREQUAL "flush1" OR "${voltest}" STREQUAL "flush2")
+      if ("${volname}" STREQUAL "multi" OR "${volname}" STREQUAL "split")
+        if (NOT BUILD_SHARED_LIBS AND NOT ${HDF_CFG_NAME} MATCHES "Debug")
+          add_test (NAME VOL-${volname}-${voltest}
+              COMMAND "${CMAKE_COMMAND}"
+                  -D "TEST_PROGRAM=$<TARGET_FILE:${voltest}>"
+                  -D "TEST_ARGS:STRING="
+                  -D "TEST_VOL:STRING=${volinfo}"
+                  -D "TEST_EXPECT=${resultcode}"
+                  -D "TEST_OUTPUT=${volname}-${voltest}"
+                  -D "TEST_FOLDER=${PROJECT_BINARY_DIR}/${volname}"
+                  -P "${HDF_RESOURCES_DIR}/volTest.cmake"
+          )
+          set_tests_properties (VOL-${volname}-${voltest} PROPERTIES
+              ENVIRONMENT "srcdir=${HDF5_TEST_BINARY_DIR}/${volname}"
+              WORKING_DIRECTORY ${HDF5_TEST_BINARY_DIR}/${volname}
+          )
+          if (BUILD_SHARED_LIBS)
+            add_test (NAME VOL-${volname}-${test}-shared
+                COMMAND "${CMAKE_COMMAND}"
+                    -D "TEST_PROGRAM=$<TARGET_FILE:${voltest}-shared>"
+                    -D "TEST_ARGS:STRING="
+                    -D "TEST_VOL:STRING=${volinfo}"
+                    -D "TEST_EXPECT=${resultcode}"
+                    -D "TEST_OUTPUT=${volname}-${voltest}-shared"
+                    -D "TEST_FOLDER=${PROJECT_BINARY_DIR}/${volname}-shared"
+                    -P "${HDF_RESOURCES_DIR}/volTest.cmake"
+            )
+            set_tests_properties (VOL-${volname}-${voltest}-shared PROPERTIES
+                ENVIRONMENT "srcdir=${HDF5_TEST_BINARY_DIR}/${volname}-shared"
+                WORKING_DIRECTORY ${HDF5_TEST_BINARY_DIR}/${volname}-shared
+            )
+          endif ()
+        else ()
+          add_test (NAME VOL-${volname}-${voltest}
+              COMMAND ${CMAKE_COMMAND} -E echo "SKIP VOL-${volname}-${voltest}"
+          )
+          if (BUILD_SHARED_LIBS)
+            add_test (NAME VOL-${volname}-${test}-shared
+                COMMAND ${CMAKE_COMMAND} -E echo "SKIP VOL-${volname}-${voltest}-shared"
+            )
+          endif ()
+        endif ()
+      else ()
+        add_test (NAME VOL-${volname}-${voltest}
+            COMMAND "${CMAKE_COMMAND}"
+                -D "TEST_PROGRAM=$<TARGET_FILE:${voltest}>"
+                -D "TEST_ARGS:STRING="
+                -D "TEST_VOL:STRING=${volinfo}"
+                -D "TEST_EXPECT=${resultcode}"
+                -D "TEST_OUTPUT=${volname}-${voltest}"
+                -D "TEST_FOLDER=${PROJECT_BINARY_DIR}/${volname}"
+                -P "${HDF_RESOURCES_DIR}/volTest.cmake"
+        )
+        set_tests_properties (VOL-${volname}-${voltest} PROPERTIES
+            ENVIRONMENT "srcdir=${HDF5_TEST_BINARY_DIR}/${volname}"
+            WORKING_DIRECTORY ${HDF5_TEST_BINARY_DIR}/${volname}
+        )
+        if (BUILD_SHARED_LIBS)
+          add_test (NAME VOL-${volname}-${test}-shared
+              COMMAND "${CMAKE_COMMAND}"
+                -D "TEST_PROGRAM=$<TARGET_FILE:${voltest}-shared>"
+                -D "TEST_ARGS:STRING="
+                -D "TEST_VOL:STRING=${volinfo}"
+                -D "TEST_EXPECT=${resultcode}"
+                -D "TEST_OUTPUT=${volname}-${voltest}-shared"
+                -D "TEST_FOLDER=${PROJECT_BINARY_DIR}/${volname}-shared"
+                -P "${HDF_RESOURCES_DIR}/volTest.cmake"
+          )
+          set_tests_properties (VOL-${volname}-${voltest}-shared PROPERTIES
+              ENVIRONMENT "srcdir=${HDF5_TEST_BINARY_DIR}/${volname}-shared"
+              WORKING_DIRECTORY ${HDF5_TEST_BINARY_DIR}/${volname}-shared
+          )
+        endif ()
+      endif ()
+    else ()
+      add_test (NAME VOL-${volname}-${voltest}
+          COMMAND "${CMAKE_COMMAND}"
+              -D "TEST_PROGRAM=$<TARGET_FILE:${voltest}>"
+              -D "TEST_ARGS:STRING="
+              -D "TEST_VOL:STRING=${volinfo}"
+              -D "TEST_EXPECT=${resultcode}"
+              -D "TEST_OUTPUT=${volname}-${voltest}"
+              -D "TEST_FOLDER=${PROJECT_BINARY_DIR}/${volname}"
+              -P "${HDF_RESOURCES_DIR}/volTest.cmake"
+      )
+      set_tests_properties (VOL-${volname}-${voltest} PROPERTIES
+          ENVIRONMENT "srcdir=${HDF5_TEST_BINARY_DIR}/${volname};HDF5TestExpress=${HDF_TEST_EXPRESS}"
+          WORKING_DIRECTORY ${HDF5_TEST_BINARY_DIR}/${volname}
+      )
+      if (BUILD_SHARED_LIBS AND NOT "${voltest}" STREQUAL "cache")
+        add_test (NAME VOL-${volname}-${voltest}-shared
+            COMMAND "${CMAKE_COMMAND}"
+                -D "TEST_PROGRAM=$<TARGET_FILE:${voltest}-shared>"
+                -D "TEST_ARGS:STRING="
+                -D "TEST_VOL:STRING=${volinfo}"
+                -D "TEST_EXPECT=${resultcode}"
+                -D "TEST_OUTPUT=${volname}-${voltest}-shared"
+                -D "TEST_FOLDER=${PROJECT_BINARY_DIR}/${volname}-shared"
+                -P "${HDF_RESOURCES_DIR}/volTest.cmake"
+        )
+        set_tests_properties (VOL-${volname}-${voltest}-shared PROPERTIES
+            ENVIRONMENT "srcdir=${HDF5_TEST_BINARY_DIR}/${volname}-shared;HDF5TestExpress=${HDF_TEST_EXPRESS}"
+            WORKING_DIRECTORY ${HDF5_TEST_BINARY_DIR}/${volname}-shared
+        )
+        endif ()
+    endif ()
+  endmacro ()
+
+  macro (DO_VOL_TEST voltest volname volinfo resultcode)
+      #message(STATUS "${voltest}-${volname} with ${volinfo}")
+      add_test (NAME VOL-${volname}-${voltest}
+          COMMAND "${CMAKE_COMMAND}"
+              -D "TEST_PROGRAM=$<TARGET_FILE:${voltest}>"
+              -D "TEST_ARGS:STRING="
+              -D "TEST_VOL:STRING=${volinfo}"
+              -D "TEST_EXPECT=${resultcode}"
+              -D "TEST_OUTPUT=${volname}-${voltest}"
+              -D "TEST_FOLDER=${PROJECT_BINARY_DIR}/${volname}"
+              -P "${HDF_RESOURCES_DIR}/volTest.cmake"
+      )
+      set_tests_properties (VOL-${volname}-${voltest} PROPERTIES
+          ENVIRONMENT "srcdir=${HDF5_TEST_BINARY_DIR}/${volname}"
+          WORKING_DIRECTORY ${HDF5_TEST_BINARY_DIR}/${volname}
+      )
+      if (BUILD_SHARED_LIBS)
+        add_test (NAME VOL-${volname}-${voltest}-shared
+            COMMAND "${CMAKE_COMMAND}"
+                -D "TEST_PROGRAM=$<TARGET_FILE:${voltest}-shared>"
+                -D "TEST_ARGS:STRING="
+                -D "TEST_VOL:STRING=${volinfo}"
+                -D "TEST_EXPECT=${resultcode}"
+                -D "TEST_OUTPUT=${volname}-${voltest}-shared"
+                -D "TEST_FOLDER=${PROJECT_BINARY_DIR}/${volname}-shared"
+                -P "${HDF_RESOURCES_DIR}/volTest.cmake"
+        )
+        set_tests_properties (VOL-${volname}-${voltest}-shared PROPERTIES
+            ENVIRONMENT "srcdir=${HDF5_TEST_BINARY_DIR}/${volname}-shared"
+            WORKING_DIRECTORY ${HDF5_TEST_BINARY_DIR}/${volname}-shared
+        )
+      endif ()
+  endmacro ()
+
+  macro (ADD_VOL_TEST volname volinfo resultcode)
+    #message(STATUS "volname=${volname} volinfo=${volinfo}")
+    foreach (test ${H5_TESTS})
+      if (NOT ${test} IN_LIST H5_VOL_SKIP_TESTS)
+        if (WIN32)
+          CHECK_VOL_TEST (${test} ${volname} "${volinfo}" ${resultcode})
+        else ()
+          DO_VOL_TEST (${test} ${volname} "${volinfo}" ${resultcode})
+        endif ()
+      endif ()
+    endforeach ()
+    set_tests_properties (VOL-${volname}-flush2 PROPERTIES DEPENDS VOL-${volname}-flush1)
+    set_tests_properties (VOL-${volname}-flush1 PROPERTIES TIMEOUT 10)
+    set_tests_properties (VOL-${volname}-flush2 PROPERTIES TIMEOUT 10)
+    set_tests_properties (VOL-${volname}-istore PROPERTIES TIMEOUT 1800)
+    if (NOT CYGWIN)
+      set_tests_properties (VOL-${volname}-cache PROPERTIES TIMEOUT 1800)
+    endif ()
+    if (BUILD_SHARED_LIBS)
+      set_tests_properties (VOL-${volname}-flush2-shared PROPERTIES DEPENDS VOL-${volname}-flush1-shared)
+      set_tests_properties (VOL-${volname}-flush1-shared PROPERTIES TIMEOUT 10)
+      set_tests_properties (VOL-${volname}-flush2-shared PROPERTIES TIMEOUT 10)
+      set_tests_properties (VOL-${volname}-istore-shared PROPERTIES TIMEOUT 1800)
+      if (NOT CYGWIN AND NOT WIN32)
+        set_tests_properties (VOL-${volname}-cache-shared PROPERTIES TIMEOUT 1800)
+      endif ()
+    endif ()
+    if (HDF5_TEST_FHEAP_VOL)
+      add_test (NAME VOL-${volname}-fheap
+          COMMAND "${CMAKE_COMMAND}"
+              -D "TEST_PROGRAM=$<TARGET_FILE:fheap>"
+              -D "TEST_ARGS:STRING="
+              -D "TEST_VOL:STRING=${volinfo}"
+              -D "TEST_EXPECT=${resultcode}"
+              -D "TEST_OUTPUT=${volname}-fheap"
+              -D "TEST_FOLDER=${PROJECT_BINARY_DIR}/${volname}"
+              -P "${HDF_RESOURCES_DIR}/volTest.cmake"
+      )
+      set_tests_properties (VOL-${volname}-fheap PROPERTIES
+          TIMEOUT 1800
+          ENVIRONMENT "srcdir=${HDF5_TEST_BINARY_DIR}/${volname};HDF5TestExpress=${HDF_TEST_EXPRESS}"
+          WORKING_DIRECTORY ${HDF5_TEST_BINARY_DIR}/${volname}
+      )
+      if (BUILD_SHARED_LIBS)
+        add_test (NAME VOL-${volname}-fheap-shared
+            COMMAND "${CMAKE_COMMAND}"
+                -D "TEST_PROGRAM=$<TARGET_FILE:fheap-shared>"
+                -D "TEST_ARGS:STRING="
+                -D "TEST_VOL:STRING=${volinfo}"
+                -D "TEST_EXPECT=${resultcode}"
+                -D "TEST_OUTPUT=${volname}-fheap-shared"
+                -D "TEST_FOLDER=${PROJECT_BINARY_DIR}/${volname}-shared"
+                -P "${HDF_RESOURCES_DIR}/volTest.cmake"
+        )
+        set_tests_properties (VOL-${volname}-fheap-shared PROPERTIES
+            TIMEOUT 1800
+            ENVIRONMENT "srcdir=${HDF5_TEST_BINARY_DIR}/${volname}-shared;HDF5TestExpress=${HDF_TEST_EXPRESS}"
+            WORKING_DIRECTORY ${HDF5_TEST_BINARY_DIR}/${volname}-shared
+        )
+      endif ()
+    endif ()
+  endmacro ()
+
+  # Run test with different Virtual File Driver
+  foreach (volname ${VOL_LIST})
+    #message(STATUS "volname=${volname}")
+    foreach (volinfo IN LISTS ${volname})
+      #message(STATUS "${volname} volinfo=${volinfo}")
+      ADD_VOL_TEST (${volname} "${volinfo}" 0)
+    endforeach ()
+  endforeach ()
+
diff --git a/test/Makefile.am b/test/Makefile.am
index 1526eca..1a232ab 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -41,8 +41,8 @@ SCRIPT_DEPEND = error_test$(EXEEXT) err_compat$(EXEEXT) links_env$(EXEEXT) filen
     swmr_sparse_reader$(EXEEXT) swmr_sparse_writer$(EXEEXT) swmr_start_write$(EXEEXT) \
     vds_swmr_gen$(EXEEXT) vds_swmr_reader$(EXEEXT) vds_swmr_writer$(EXEEXT)
 if HAVE_SHARED_CONDITIONAL
-  TEST_SCRIPT += test_filter_plugin.sh
-  SCRIPT_DEPEND += filter_plugin$(EXEEXT)
+  TEST_SCRIPT += test_filter_plugin.sh test_vol_plugin.sh
+  SCRIPT_DEPEND += filter_plugin$(EXEEXT) vol_plugin$(EXEEXT)
 endif
 
 check_SCRIPTS = $(TEST_SCRIPT)
@@ -52,8 +52,8 @@ check_SCRIPTS = $(TEST_SCRIPT)
 # As an exception, long-running tests should occur earlier in the list.
 # This gives them more time to run when tests are executing in parallel.
 TEST_PROG= testhdf5 \
-           cache cache_api cache_image cache_tagging lheap ohdr stab gheap \
-           evict_on_close farray earray btree2 fheap \
+           cache cache_api cache_image cache_tagging lheap ohdr \
+           stab gheap evict_on_close farray earray btree2 fheap \
            pool accum hyperslab istore bittests dt_arith page_buffer \
            dtypes dsets cmpd_dset filter_fail extend direct_chunk external efc \
            objcopy links unlink twriteorder big mtime fillval mount \
@@ -83,7 +83,7 @@ check_PROGRAMS=$(TEST_PROG) error_test err_compat tcheck_version \
     swmr_remove_writer swmr_addrem_writer swmr_sparse_reader swmr_sparse_writer \
     swmr_check_compat_vfd vds_swmr_gen vds_swmr_reader vds_swmr_writer
 if HAVE_SHARED_CONDITIONAL
-  check_PROGRAMS+= filter_plugin
+  check_PROGRAMS+= filter_plugin vol_plugin
 endif
 
 # These programs generate test files for the tests.  They don't need to be
@@ -106,9 +106,7 @@ if HAVE_SHARED_CONDITIONAL
   # The libh5test library provides common support code for the tests.
   # The filter_plugin* libraries are for use in filter_plugin.c.
   # Build them as shared libraries if that option was enabled in configure.
-  #
-  # echo_vol is used for testing VOL plugin functionality.
-  noinst_LTLIBRARIES=libh5test.la libfilter_plugin1_dsets.la libfilter_plugin2_dsets.la libfilter_plugin3_dsets.la libfilter_plugin4_groups.la echo_vol.la
+  noinst_LTLIBRARIES=libh5test.la libfilter_plugin1_dsets.la libfilter_plugin2_dsets.la libfilter_plugin3_dsets.la libfilter_plugin4_groups.la libnull_vol_connector.la
   libfilter_plugin1_dsets_la_SOURCES=filter_plugin1_dsets.c
   libfilter_plugin2_dsets_la_SOURCES=filter_plugin2_dsets.c
   libfilter_plugin3_dsets_la_SOURCES=filter_plugin3_dsets.c
@@ -121,8 +119,10 @@ if HAVE_SHARED_CONDITIONAL
   libfilter_plugin4_groups_la_LIBADD=$(LIBHDF5)
 
   # VOL plugin test libraries
-  echo_vol_la_SOURCES=echo_vol.c
-  echo_vol_la_LDFLAGS=$(AM_LDFLAGS) -avoid-version -module -shared -export-dynamic -rpath /nowhere
+  #
+  # null_vol_connector is used for testing basic VOL plugin functionality.
+  libnull_vol_connector_la_SOURCES=null_vol_connector.c
+  libnull_vol_connector_la_LDFLAGS=$(AM_LDFLAGS) -avoid-version -module -shared -export-dynamic -rpath /nowhere
 
 else
   # The libh5test library provides common support code for the tests.
@@ -177,6 +177,7 @@ CHECK_CLEANFILES+=accum.h5 cmpd_dset.h5 compact_dataset.h5 dataset.h5 dset_offse
     extend.h5 istore.h5 extlinks*.h5 frspace.h5 links*.h5 \
     sys_file1 tfile[1-7].h5 th5s[1-4].h5 lheap.h5 fheap.h5 ohdr.h5 \
     stab.h5 extern_[1-5].h5 extern_[1-4][rw].raw gheap[0-4].h5 \
+    ohdr_min_a.h5 ohdr_min_b.h5 min_dset_ohdr_testfile.h5\
     dt_arith[1-2] links.h5 links[0-6]*.h5 extlinks[0-15].h5 tmp \
     big.data big[0-9][0-9][0-9][0-9][0-9].h5  \
     stdio.h5 sec2.h5 dtypes[0-9].h5 dtypes1[0].h5 dt_arith[1-2].h5 tattr.h5 \
@@ -220,6 +221,7 @@ use_disable_mdc_flushes_SOURCES=use_disable_mdc_flushes.c
 
 # Temporary files.
 DISTCLEANFILES=testerror.sh testlibinfo.sh testcheck_version.sh testlinks_env.sh test_filter_plugin.sh \
-    testswmr.sh testvdsswmr.sh test_usecases.sh testflushrefresh.sh test_filenotclosed.sh
+    testswmr.sh testvdsswmr.sh test_usecases.sh testflushrefresh.sh test_filenotclosed.sh \
+	test_vol_plugin.sh
 
 include $(top_srcdir)/config/conclude.am
diff --git a/test/dsets.c b/test/dsets.c
index 5cd376a..e63878c 100644
--- a/test/dsets.c
+++ b/test/dsets.c
@@ -86,6 +86,9 @@ const char *FILENAME[] = {
     NULL
 };
 
+#define OHMIN_FILENAME_A "ohdr_min_a"
+
+
 #define FILENAME_BUF_SIZE       1024
 #define KB                      1024
 
@@ -338,7 +341,7 @@ filter_count(unsigned int flags, size_t H5_ATTR_UNUSED cd_nelmts,
         count_nbytes_written += nbytes;
 
     return nbytes;
-}
+} /* end filter_count() */
 
 
 /*-------------------------------------------------------------------------
@@ -481,11 +484,11 @@ test_create(hid_t file)
     if(H5Dclose(dataset) < 0) goto error;
 
     PASSED();
-    return 0;
+    return SUCCEED;
 
  error:
-    return -1;
-}
+    return FAIL;
+} /* end test_create() */
 
 
 /*-------------------------------------------------------------------------
@@ -605,7 +608,7 @@ test_simple_io(const char *env_h5_drvr, hid_t fapl)
         puts("    Current VFD doesn't support continuous address space");
     } /* end else */
 
-    return 0;
+    return SUCCEED;
 
 error:
     if(space > 0)
@@ -620,8 +623,8 @@ error:
         HDclose(f);
     if(tconv_buf)
         HDfree(tconv_buf);
-    return -1;
-}
+    return FAIL;
+} /* end test_simple_io() */
 
 
 /*-------------------------------------------------------------------------
@@ -713,7 +716,7 @@ test_userblock_offset(const char *env_h5_drvr, hid_t fapl, hbool_t new_format)
         puts("    Current VFD doesn't support continuous address space");
     } /* end else */
 
-    return 0;
+    return SUCCEED;
 
 error:
     if(space > 0)
@@ -726,8 +729,8 @@ error:
         if(H5Fclose(file) < 0) TEST_ERROR
     if(f > 0)
         HDclose(f);
-    return -1;
-}
+    return FAIL;
+} /* end test_userblock_offset() */
 
 
 /*-------------------------------------------------------------------------
@@ -826,7 +829,7 @@ test_compact_io(hid_t fapl)
      **************************************/
 
     /* Create a copy of file access property list */
-    if((new_fapl = new_fapl = h5_fileaccess()) < 0) TEST_ERROR
+    if((new_fapl = h5_fileaccess()) < 0) TEST_ERROR
 
     /* Loop through all the combinations of low/high library format bounds,
        skipping invalid combinations.
@@ -907,7 +910,7 @@ test_compact_io(hid_t fapl)
     if(H5Pclose(plist) < 0) TEST_ERROR
 
     PASSED();
-    return 0;
+    return SUCCEED;
 
  error:
     H5E_BEGIN_TRY {
@@ -919,8 +922,8 @@ test_compact_io(hid_t fapl)
         H5Fclose(verfile);
     } H5E_END_TRY;
 
-    return -1;
-}
+    return FAIL;
+} /* end test_compact_io() */
 
 
 /*-------------------------------------------------------------------------
@@ -1056,7 +1059,7 @@ test_max_compact(hid_t fapl)
          FAIL_STACK_ERROR
 
      PASSED();
-     return 0;
+     return SUCCEED;
 
 error:
     if(wbuf)
@@ -1072,7 +1075,7 @@ error:
         H5Fclose(file);
     } H5E_END_TRY;
 
-     return -1;
+     return FAIL;
 } /* end test_max_compact() */
 
 
@@ -1181,7 +1184,7 @@ test_layout_extend(hid_t fapl)
     if(H5Fclose(fid) < 0) FAIL_STACK_ERROR
 
     PASSED();
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -1195,7 +1198,7 @@ error:
         H5Fclose(fid);
     } H5E_END_TRY;
 
-     return -1;
+     return FAIL;
 } /* end test_layout_extend() */
 
 
@@ -1331,7 +1334,7 @@ test_conv_buffer(hid_t fid)
   HDfree(cf);
   HDfree(cfrR);
   puts(" PASSED");
-  return 0;
+  return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -1347,8 +1350,8 @@ error:
         H5Dclose(dataset);
     } H5E_END_TRY;
 
-  return -1;
-}
+  return FAIL;
+} /* end test_conv_buffer() */
 
 
 /*-------------------------------------------------------------------------
@@ -1418,7 +1421,7 @@ test_tconv(hid_t file)
     HDfree(in);
 
     puts(" PASSED");
-    return 0;
+    return SUCCEED;
 
 error:
     if(out)
@@ -1431,8 +1434,8 @@ error:
         H5Sclose(space);
     } H5E_END_TRY;
 
-    return -1;
-}
+    return FAIL;
+} /* end test_tconv() */
 
 /* This message derives from H5Z */
 const H5Z_class2_t H5Z_BOGUS[1] = {{
@@ -1465,7 +1468,7 @@ can_apply_bogus(hid_t H5_ATTR_UNUSED dcpl_id, hid_t type_id, hid_t H5_ATTR_UNUSE
         return 1;
     else
         return -1;
-}
+} /* end can_apply_bogus() */
 
 
 /*-------------------------------------------------------------------------
@@ -1483,7 +1486,7 @@ filter_bogus(unsigned int H5_ATTR_UNUSED flags, size_t H5_ATTR_UNUSED cd_nelmts,
       size_t H5_ATTR_UNUSED *buf_size, void H5_ATTR_UNUSED **buf)
 {
     return nbytes;
-}
+} /* end filter_bogus() */
 
 
 /*-------------------------------------------------------------------------
@@ -1583,7 +1586,7 @@ filter_bogus2(unsigned int flags, size_t cd_nelmts,
     /* Filter is "no op" */
     else
         return(nbytes);
-}
+} /* end filter_bogus2() */
 
 
 /*-------------------------------------------------------------------------
@@ -1601,7 +1604,7 @@ filter_bogus3(unsigned int H5_ATTR_UNUSED flags, size_t H5_ATTR_UNUSED cd_nelmts
       size_t H5_ATTR_UNUSED *buf_size, void H5_ATTR_UNUSED **buf)
 {
     return 0;
-}
+} /* end filter_bogus3() */
 
 /* This message derives from H5Z */
 const H5Z_class2_t H5Z_CORRUPT[1] = {{
@@ -1690,7 +1693,7 @@ filter_cb_cont(H5Z_filter_t filter, void H5_ATTR_UNUSED *buf, size_t H5_ATTR_UNU
        return H5Z_CB_CONT;
     else
         return H5Z_CB_FAIL;
-}
+} /* end filter_cb_cont() */
 
 
 /*-------------------------------------------------------------------------
@@ -1709,7 +1712,7 @@ filter_cb_fail(H5Z_filter_t filter, void H5_ATTR_UNUSED *buf, size_t H5_ATTR_UNU
        return H5Z_CB_FAIL;
     else
        return H5Z_CB_CONT;
-}
+} /* end filter_cb_fail() */
 
 
 /*-------------------------------------------------------------------------
@@ -2052,13 +2055,13 @@ test_filter_internal(hid_t fid, const char *name, hid_t dcpl, int if_fletcher32,
     if(H5Pclose (write_dxpl) < 0) goto error;
     HDfree (tconv_buf);
 
-    return(0);
+    return SUCCEED;
 
 error:
     if(tconv_buf)
         HDfree (tconv_buf);
-    return -1;
-}
+    return FAIL;
+} /* end test_filter_internal() */
 
 /*-------------------------------------------------------------------------
  * Function:  test_filter_noencoder
@@ -2160,7 +2163,7 @@ test_filter_noencoder(const char *dset_name)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
     H5_FAILED();
@@ -2175,8 +2178,8 @@ error:
     if(file_id != -1)
         H5Fclose(file_id);
 
-    return -1;
-}
+    return FAIL;
+} /* end test_filter_noencoder() */
 #endif /* H5_HAVE_FILTER_SZIP */
 
 /*-------------------------------------------------------------------------
@@ -2242,11 +2245,11 @@ test_get_filter_info(void)
   if(err >= 0) TEST_ERROR
 
   PASSED();
-  return 0;
+  return SUCCEED;
 
 error:
-  return -1;
-}
+  return FAIL;
+} /* end test_get_filter_info() */
 
 /*-------------------------------------------------------------------------
  * Function:  test_filters
@@ -2517,11 +2520,11 @@ H5_ATTR_UNUSED
     SKIPPED();
     puts("    szip filter not enabled");
 #endif /* H5_HAVE_FILTER_SZIP */
-    return 0;
+    return SUCCEED;
 
 error:
-    return -1;
-}
+    return FAIL;
+} /* end test_filters() */
 
 
 /*-------------------------------------------------------------------------
@@ -2856,11 +2859,11 @@ test_onebyte_shuffle(hid_t file)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
-    return -1;
-}
+    return FAIL;
+} /* end test_onebyte_shuffle() */
 
 
 /*-------------------------------------------------------------------------
@@ -2974,11 +2977,11 @@ test_nbit_int(hid_t file)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
-    return -1;
-}
+    return FAIL;
+} /* end test_nbit_int() */
 
 
 /*-------------------------------------------------------------------------
@@ -3092,11 +3095,11 @@ test_nbit_float(hid_t file)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
-    return -1;
-}
+    return FAIL;
+} /* end test_nbit_float() */
 
 
 /*-------------------------------------------------------------------------
@@ -3224,11 +3227,11 @@ test_nbit_double(hid_t file)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
-    return -1;
-}
+    return FAIL;
+} /* end test_nbit_double() */
 
 
 /*-------------------------------------------------------------------------
@@ -3351,11 +3354,11 @@ test_nbit_array(hid_t file)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
-    return -1;
-}
+    return FAIL;
+} /* end test_nbit_array() */
 
 
 /*-------------------------------------------------------------------------
@@ -3568,11 +3571,11 @@ test_nbit_compound(hid_t file)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
-    return -1;
-}
+    return FAIL;
+} /* end test_nbit_compound() */
 
 
 /*-------------------------------------------------------------------------
@@ -3913,11 +3916,11 @@ out:
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
-    return -1;
-}
+    return FAIL;
+} /* end test_nbit_compound_2() */
 
 
 /*-------------------------------------------------------------------------
@@ -4093,11 +4096,11 @@ test_nbit_compound_3(hid_t file)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
-    return -1;
-}
+    return FAIL;
+} /* end test_nbit_compound_3() */
 
 
 /*-------------------------------------------------------------------------
@@ -4261,10 +4264,10 @@ test_nbit_int_size(hid_t file)
 
     PASSED();
 
-   return 0;
+   return SUCCEED;
 error:
-    return -1;
-}
+    return FAIL;
+} /* end test_nbit_int_size() */
 
 
 /*-------------------------------------------------------------------------
@@ -4458,10 +4461,10 @@ test_nbit_flt_size(hid_t file)
 
     PASSED();
 
-   return 0;
+   return SUCCEED;
 error:
-    return -1;
-}
+    return FAIL;
+} /* end test_nbit_flt_size() */
 
 /*-------------------------------------------------------------------------
  * Function:    test_scaleoffset_int
@@ -4569,10 +4572,10 @@ test_scaleoffset_int(hid_t file)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 error:
-    return -1;
-}
+    return FAIL;
+} /* end test_scaleoffset_int() */
 
 
 /*-------------------------------------------------------------------------
@@ -4697,10 +4700,10 @@ test_scaleoffset_int_2(hid_t file)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 error:
-    return -1;
-}
+    return FAIL;
+} /* end test_scaleoffset_int_2() */
 
 
 /*-------------------------------------------------------------------------
@@ -4810,10 +4813,10 @@ test_scaleoffset_float(hid_t file)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 error:
-    return -1;
-}
+    return FAIL;
+} /* end test_scaleoffset_float() */
 
 
 /*-------------------------------------------------------------------------
@@ -4939,10 +4942,10 @@ test_scaleoffset_float_2(hid_t file)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 error:
-    return -1;
-}
+    return FAIL;
+} /* end test_scaleoffset_float_2() */
 
 
 /*-------------------------------------------------------------------------
@@ -5052,10 +5055,10 @@ test_scaleoffset_double(hid_t file)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 error:
-    return -1;
-}
+    return FAIL;
+} /* end test_scaleoffset_double() */
 
 
 /*-------------------------------------------------------------------------
@@ -5182,10 +5185,10 @@ test_scaleoffset_double_2(hid_t file)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 error:
-    return -1;
-}
+    return FAIL;
+} /* end test_scaleoffset_double_2() */
 
 
 /*-------------------------------------------------------------------------
@@ -5242,17 +5245,17 @@ test_multiopen (hid_t file)
     if(H5Pclose(dcpl) < 0) goto error;
 
     PASSED();
-    return 0;
+    return SUCCEED;
 
  error:
     H5E_BEGIN_TRY {
-    H5Dclose(dset1);
-    H5Dclose(dset2);
-    H5Sclose(space);
-    H5Pclose(dcpl);
+        H5Dclose(dset1);
+        H5Dclose(dset2);
+        H5Sclose(space);
+        H5Pclose(dcpl);
     } H5E_END_TRY;
-    return -1;
-}
+    return FAIL;
+} /* end test_multiopen() */
 
 
 /*-------------------------------------------------------------------------
@@ -5338,7 +5341,7 @@ test_types(hid_t file)
     /* Cleanup */
     if(H5Gclose(grp) < 0) goto error;
     PASSED();
-    return 0;
+    return SUCCEED;
 
  error:
     H5E_BEGIN_TRY {
@@ -5347,8 +5350,8 @@ test_types(hid_t file)
     H5Sclose(space);
     H5Dclose(dset);
     } H5E_END_TRY;
-    return -1;
-}
+    return FAIL;
+} /* end test_types() */
 
 /* This message derives from H5Z */
 const H5Z_class2_t H5Z_CAN_APPLY_TEST[1] = {{
@@ -5525,10 +5528,10 @@ test_can_apply(hid_t file)
 
 
     PASSED();
-    return 0;
+    return SUCCEED;
 
 error:
-    return -1;
+    return FAIL;
 } /* end test_can_apply() */
 
 /* This message derives from H5Z */
@@ -5684,10 +5687,10 @@ test_can_apply2(hid_t file)
 
 
     PASSED();
-    return 0;
+    return SUCCEED;
 
 error:
-    return -1;
+    return FAIL;
 } /* end test_can_apply2() */
 
 
@@ -5876,11 +5879,11 @@ file)
     SKIPPED();
     puts("    Szip filter is not enabled.");
 #endif /* H5_HAVE_FILTER_SZIP */
-    return 0;
+    return SUCCEED;
 
 #ifdef H5_HAVE_FILTER_SZIP
 error:
-    return -1;
+    return FAIL;
 #endif /* H5_HAVE_FILTER_SZIP */
 } /* end test_can_apply_szip() */
 
@@ -6155,10 +6158,10 @@ test_set_local(hid_t fapl)
 
 
     PASSED();
-    return 0;
+    return SUCCEED;
 
 error:
-    return -1;
+    return FAIL;
 } /* end test_set_local() */
 
 
@@ -6233,7 +6236,7 @@ test_compare_dcpl(hid_t file)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -6243,7 +6246,7 @@ error:
         H5Pclose(dcpl1);
         H5Pclose(dcpl2);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* end test_compare_dcpl() */
 
 
@@ -6360,7 +6363,7 @@ test_copy_dcpl(hid_t file, hid_t fapl)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -6375,7 +6378,7 @@ error:
         H5Pclose(dcpl1_copy);
         H5Pclose(dcpl2_copy);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* end test_copy_dcpl() */
 
 
@@ -6492,7 +6495,7 @@ test_filter_delete(hid_t file)
 #else
     SKIPPED();
 #endif
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -6501,7 +6504,7 @@ error:
         H5Dclose(dsid);
         H5Sclose(sid);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* end test_filter_delete() */
 
 
@@ -6574,7 +6577,7 @@ auxread_fdata(hid_t fid, const char *name)
     if(buf)
         HDfree(buf);
 
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -6586,8 +6589,8 @@ error:
         if(buf)
             HDfree(buf);
     } H5E_END_TRY;
-    return -1;
-}
+    return FAIL;
+} /* end auxread_fdata() */
 
 
 /*-------------------------------------------------------------------------
@@ -6647,7 +6650,7 @@ test_filters_endianess(void)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -6656,7 +6659,7 @@ error:
         H5Sclose(sid);
         H5Fclose(fid);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* end test_filters_endianess() */
 
 
@@ -6806,7 +6809,7 @@ test_zero_dims(hid_t file)
     if(H5Sclose(s2) < 0) FAIL_STACK_ERROR
 
     PASSED();
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -6820,7 +6823,7 @@ error:
         H5Dclose(d2);
         H5Sclose(s2);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* end test_zero_dims() */
 
 
@@ -6999,7 +7002,7 @@ test_missing_chunk(hid_t file)
     if(H5Dclose(did2) < 0) TEST_ERROR;
 
     PASSED();
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -7012,7 +7015,7 @@ error:
         H5Sclose(s);
         H5Sclose(sid2);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* end test_missing_chunk() */
 
 
@@ -7370,7 +7373,7 @@ test_random_chunks_real(const char *testname, hbool_t early_alloc, hid_t fapl)
     if(H5Fclose(file) < 0) TEST_ERROR;
 
     PASSED();
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -7380,7 +7383,7 @@ error:
         H5Dclose(d);
         H5Fclose(file);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* end test_random_chunks_real() */
 
 
@@ -7627,10 +7630,10 @@ test_deprec(hid_t file)
 
     if(H5Pclose(dcpl) < 0) goto error;
 
-    return 0;
+    return SUCCEED;
 
  error:
-    return -1;
+    return FAIL;
 } /* end test_deprec() */
 #endif /* H5_NO_DEPRECATED_SYMBOLS */
 
@@ -7734,7 +7737,7 @@ test_huge_chunks(hid_t fapl)
     if(H5Fclose(fid) < 0) FAIL_STACK_ERROR
 
     PASSED();
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -7743,7 +7746,7 @@ error:
         H5Sclose(sid);
         H5Fclose(fid);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* end test_huge_chunks() */
 
 
@@ -7938,7 +7941,7 @@ test_chunk_cache(hid_t fapl)
     if (H5Fclose(fid) < 0) FAIL_STACK_ERROR
 
     PASSED();
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -7951,7 +7954,7 @@ error:
         H5Sclose(sid);
         H5Fclose(fid);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* end test_chunk_cache() */
 
 
@@ -8225,7 +8228,7 @@ test_big_chunks_bypass_cache(hid_t fapl)
     HDfree(rdata2);
 
     PASSED();
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -8244,7 +8247,7 @@ error:
         HDfree(rdata1);
     if(rdata2)
         HDfree(rdata2);
-    return -1;
+    return FAIL;
 } /* end test_big_chunks_bypass_cache() */
 
 
@@ -8580,7 +8583,7 @@ test_chunk_fast(const char *env_h5_driver, hid_t fapl)
     if(H5Pclose(my_fapl) < 0) FAIL_STACK_ERROR
 
     PASSED();
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -8591,7 +8594,7 @@ error:
         H5Fclose(fid);
         H5Pclose(my_fapl);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* end test_chunk_fast() */
 
 
@@ -8704,7 +8707,7 @@ test_reopen_chunk_fast(hid_t fapl)
     } /* end for */
 
     PASSED();
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -8714,7 +8717,7 @@ error:
         H5Sclose(scalar_sid);
         H5Fclose(fid);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* end test_reopen_chunk_fast() */
 
 
@@ -8813,7 +8816,7 @@ test_chunk_fast_bug1(hid_t fapl)
     if(H5Sclose(sid) < 0) FAIL_STACK_ERROR
 
     PASSED();
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -8822,7 +8825,7 @@ error:
         H5Sclose(sid);
         H5Fclose(fid);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* end test_chunk_fast_bug1() */
 
 /* This message derives from H5Z */
@@ -9268,7 +9271,7 @@ test_chunk_expand(hid_t fapl)
         PASSED();
     } /* end else */
 
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -9281,7 +9284,7 @@ error:
         H5Sclose(scalar_sid);
         H5Fclose(fid);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* end test_chunk_expand() */
 
 
@@ -9686,7 +9689,7 @@ test_fixed_array(hid_t fapl)
     HDfree(rbuf_big);
 
     PASSED();
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -9700,7 +9703,7 @@ error:
         HDfree(wbuf_big);
     if(rbuf_big)
         HDfree(rbuf_big);
-    return -1;
+    return FAIL;
 } /* end test_fixed_array() */
 
 
@@ -9944,7 +9947,7 @@ test_single_chunk(hid_t fapl)
     HDfree(t_rbuf);
 
     PASSED();
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -9964,7 +9967,7 @@ error:
         HDfree(t_wbuf);
     if(t_rbuf)
         HDfree(t_rbuf);
-    return -1;
+    return FAIL;
 } /* end test_single_chunk() */
 
 
@@ -10030,15 +10033,15 @@ test_idx_compatible(void)
     }
 
     PASSED();
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
         H5Dclose(did);
     H5Fclose(fid);
     } H5E_END_TRY;
-    return -1;
-} /* test_idx_compatible */
+    return FAIL;
+} /* end test_idx_compatible() */
 
 /*-------------------------------------------------------------------------
  *
@@ -10168,7 +10171,7 @@ test_unfiltered_edge_chunks(hid_t fapl)
         TEST_ERROR
 
     PASSED();
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -10177,8 +10180,8 @@ error:
         H5Sclose(sid);
         H5Fclose(fid);
     } H5E_END_TRY;
-    return -1;
-} /* test_unfiltered_edge_chunks */
+    return FAIL;
+} /* end test_unfiltered_edge_chunks() */
 
 
 /*-------------------------------------------------------------------------
@@ -10282,7 +10285,7 @@ test_large_chunk_shrink(hid_t fapl)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -10292,7 +10295,7 @@ error:
         H5Sclose(scalar_sid);
         H5Fclose(fid);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* end test_large_chunk_shrink() */
 
 
@@ -10376,7 +10379,7 @@ test_zero_dim_dset(hid_t fapl)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -10385,7 +10388,7 @@ error:
         H5Sclose(sid);
         H5Fclose(fid);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* end test_zero_dim_dset() */
 
 
@@ -10426,7 +10429,7 @@ test_swmr_non_latest(const char *env_h5_driver, hid_t fapl)
     if(!H5FD__supports_swmr_test(env_h5_driver)) {
         SKIPPED();
         HDputs("    Test skipped due to VFD not supporting SWMR I/O.");
-        return 0;
+        return SUCCEED;
     }
 
     /* Check if we are using the latest version of the format */
@@ -10625,7 +10628,7 @@ test_swmr_non_latest(const char *env_h5_driver, hid_t fapl)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -10635,7 +10638,7 @@ error:
         H5Gclose(gid);
         H5Fclose(fid);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* test_swmr_non_latest() */
 
 
@@ -10676,7 +10679,7 @@ test_earray_hdr_fd(const char *env_h5_driver, hid_t fapl)
     if(!H5FD__supports_swmr_test(env_h5_driver)) {
         SKIPPED();
         HDputs("    Test skipped due to VFD not supporting SWMR I/O.");
-        return 0;
+        return SUCCEED;
     }
 
     if((fapl = H5Pcreate(H5P_FILE_ACCESS)) < 0)
@@ -10743,7 +10746,7 @@ test_earray_hdr_fd(const char *env_h5_driver, hid_t fapl)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -10755,7 +10758,7 @@ error:
         H5Sclose(sid);
         H5Sclose(msid);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* test_earray_hdr_fd() */
 
 
@@ -10796,7 +10799,7 @@ test_farray_hdr_fd(const char *env_h5_driver, hid_t fapl)
     if(!H5FD__supports_swmr_test(env_h5_driver)) {
         SKIPPED();
         HDputs("    Test skipped due to VFD not supporting SWMR I/O.");
-        return 0;
+        return SUCCEED;
     }
 
     if((fapl = H5Pcreate(H5P_FILE_ACCESS)) < 0)
@@ -10863,7 +10866,7 @@ test_farray_hdr_fd(const char *env_h5_driver, hid_t fapl)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -10875,8 +10878,8 @@ error:
         H5Sclose(sid);
         H5Sclose(msid);
     } H5E_END_TRY;
-    return -1;
-} /* test_farray_hdr_fd() */
+    return FAIL;
+} /* end test_farray_hdr_fd() */
 
 
 /*-------------------------------------------------------------------------
@@ -10916,7 +10919,7 @@ test_bt2_hdr_fd(const char *env_h5_driver, hid_t fapl)
     if(!H5FD__supports_swmr_test(env_h5_driver)) {
         SKIPPED();
         HDputs("    Test skipped due to VFD not supporting SWMR I/O.");
-        return 0;
+        return SUCCEED;
     }
 
     if((fapl = H5Pcreate(H5P_FILE_ACCESS)) < 0)
@@ -10983,7 +10986,7 @@ test_bt2_hdr_fd(const char *env_h5_driver, hid_t fapl)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -10995,8 +10998,8 @@ error:
         H5Sclose(sid);
         H5Sclose(msid);
     } H5E_END_TRY;
-    return -1;
-} /* test_bt2_hdr_fd() */
+    return FAIL;
+} /* end test_bt2_hdr_fd() */
 
 
 /*-------------------------------------------------------------------------
@@ -11379,7 +11382,7 @@ test_storage_size(hid_t fapl)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -11389,7 +11392,7 @@ error:
         H5Sclose(sid);
         H5Fclose(fid);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* end test_storage_size() */
 
 
@@ -11470,7 +11473,7 @@ test_power2up(hid_t fapl)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -11480,7 +11483,7 @@ error:
         H5Pclose(dcpl);
         H5Fclose(fid);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* end test_power2up() */
 
 
@@ -11792,13 +11795,13 @@ test_scatter(void)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
         H5Sclose(sid);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* end test_scatter() */
 
 
@@ -11860,7 +11863,7 @@ gather_cb(const void *dst_buf, size_t dst_buf_bytes_used,
 
 error:
     return FAIL;
-}
+} /* end gather_cb() */
 
 static herr_t
 test_gather(void)
@@ -12154,13 +12157,13 @@ test_gather(void)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
         H5Sclose(sid);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* end test_gather() */
 
 
@@ -12194,7 +12197,7 @@ scatter_error_cb_fail(void **src_buf/*out*/, size_t *src_buf_bytes_used/*out*/,
     *src_buf_bytes_used = nelmts * sizeof(scatter_info->src_buf[0]);
 
     return FAIL;
-}
+} /* end scatter_error_cb_fail() */
 
 static herr_t
 scatter_error_cb_null(void **src_buf/*out*/, size_t *src_buf_bytes_used/*out*/,
@@ -12212,7 +12215,7 @@ scatter_error_cb_null(void **src_buf/*out*/, size_t *src_buf_bytes_used/*out*/,
     *src_buf_bytes_used = nelmts * sizeof(scatter_info->src_buf[0]);
 
     return SUCCEED;
-}
+} /* end scatter_error_cb_null() */
 
 static herr_t
 scatter_error_cb_unalign(void **src_buf/*out*/, size_t *src_buf_bytes_used/*out*/,
@@ -12223,7 +12226,7 @@ scatter_error_cb_unalign(void **src_buf/*out*/, size_t *src_buf_bytes_used/*out*
     *src_buf_bytes_used = *(size_t *)_src_buf_bytes_used;
 
     return SUCCEED;
-}
+} /* endscatter_error_cb_unalign() */
 
 static herr_t
 test_scatter_error(void)
@@ -12357,13 +12360,13 @@ test_scatter_error(void)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
         H5Sclose(sid);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* end test_scatter_error() */
 
 
@@ -12386,7 +12389,7 @@ gather_error_cb_fail(const void H5_ATTR_UNUSED *dst_buf,
     size_t H5_ATTR_UNUSED dst_buf_bytes_used, void H5_ATTR_UNUSED *op_data)
 {
     return FAIL;
-}
+} /* end gather_error_cb_fail() */
 
 static herr_t
 test_gather_error(void)
@@ -12496,13 +12499,13 @@ test_gather_error(void)
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
         H5Sclose(sid);
     } H5E_END_TRY;
-    return -1;
+    return FAIL;
 } /* end test_gather_error() */
 
 /*-------------------------------------------------------------------------
@@ -12599,8 +12602,8 @@ static herr_t dls_01_read_stuff( hid_t fid );
 static herr_t dls_01_main( void );
 
 static herr_t
-dls_01_setup_file( hid_t fid ) {
-
+dls_01_setup_file( hid_t fid )
+{
     int status = 0;
     hid_t sid = 0, did = 0, tid = 0, dcpl = 0;
     int ndims = 1;
@@ -12638,17 +12641,15 @@ dls_01_setup_file( hid_t fid ) {
     status = H5Sclose( sid );
     if ( status != 0 ) TEST_ERROR
 
-    return 0;
+    return SUCCEED;
 
 error:
-
-    return -1;
-
-} /* dls_01_setup_file */
+    return FAIL;
+} /* end dls_01_setup_file() */
 
 static herr_t
-dls_01_write_data( hid_t fid, char* buffer ) {
-
+dls_01_write_data( hid_t fid, char* buffer )
+{
     int status = 0;
     hid_t did = 0, tid = 0;
     hsize_t extent[1] = {4};
@@ -12674,17 +12675,15 @@ dls_01_write_data( hid_t fid, char* buffer ) {
     status = H5Dclose( did );
     if ( status != 0 ) TEST_ERROR
 
-    return 0;
+    return SUCCEED;
 
 error:
-
-    return -1;
-
-} /* dls_01_write_data */
+    return FAIL;
+} /* end dls_01_write_data() */
 
 static herr_t
-dls_01_read_stuff( hid_t fid ) {
-
+dls_01_read_stuff( hid_t fid )
+{
     int status = 0;
     hid_t did = 0;
     H5O_info_t info;
@@ -12698,17 +12697,15 @@ dls_01_read_stuff( hid_t fid ) {
     status = H5Dclose( did );
     if ( status != 0 ) TEST_ERROR
 
-    return 0;
+    return SUCCEED;
 
 error:
-
-    return -1;
-
-} /* dls_01_read_stuff() */
+    return FAIL;
+} /* end dls_01_read_stuff() */
 
 static herr_t
-dls_01_main( void ) {
-
+dls_01_main( void )
+{
     char filename[512];
     int status = 0;
     hid_t fapl = 0, fid = 0;
@@ -12765,15 +12762,12 @@ dls_01_main( void ) {
 
     PASSED();
 
-    return 0;
+    return SUCCEED;
 
 error:
-
     if ( buffer ) HDfree(buffer);
-
-    return -1;
-
-} /* dls_01_main() */
+    return FAIL;
+} /* end dls_01_main() */
 
 /*-------------------------------------------------------------------------
  * Function:    test_compact_open_close_dirty
@@ -12881,7 +12875,7 @@ test_compact_open_close_dirty(hid_t fapl)
         TEST_ERROR
 
      PASSED();
-     return 0;
+     return SUCCEED;
 
 error:
     H5E_BEGIN_TRY {
@@ -12890,8 +12884,8 @@ error:
         H5Dclose(did);
         H5Fclose(fid);
     } H5E_END_TRY;
-    return -1;
-} /* test_compact_open_close_dirty() */
+    return FAIL;
+} /* end test_compact_open_close_dirty() */
 
 
 /*-------------------------------------------------------------------------
@@ -13030,7 +13024,7 @@ test_versionbounds(void)
         TEST_ERROR
     dcpl = -1;
     PASSED();
-    return 0;
+    return SUCCEED;
 
  error:
     H5E_BEGIN_TRY {
@@ -13043,8 +13037,126 @@ test_versionbounds(void)
         H5Fclose(srcfile);
         H5Fclose(vfile);
     } H5E_END_TRY;
-    return -1;
-} /* test_versionbounds() */
+    return FAIL;
+} /* end test_versionbounds() */
+
+
+/*-----------------------------------------------------------------------------
+ * Function:   test_object_header_minimization_dcpl
+ *
+ * Purpose:    Test the "datset object header minimization" property as part of
+ *             the DCPL.
+ *
+ * Return:     Success/pass:   0
+ *             Failure/error: -1
+ *
+ * Programmer: Jacob Smith
+ *             2018 August 15
+ *
+ * Changes:    None.
+ *-----------------------------------------------------------------------------
+ */
+static herr_t
+test_object_header_minimization_dcpl(void)
+{
+    hid_t    dcpl_id  = -1;
+    hid_t    file_id  = -1;
+    char     filename[FILENAME_BUF_SIZE] = "";
+    hbool_t  minimize = FALSE;
+    herr_t   ret;
+
+    TESTING("dcpl flags to minimize dataset object header");
+
+    /*********/
+    /* SETUP */
+    /*********/
+
+    if(NULL == h5_fixname(OHMIN_FILENAME_A, H5P_DEFAULT, filename, sizeof(filename)))
+        FAIL_PUTS_ERROR("unable to prepare filename")
+
+    file_id = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
+    if (0 > file_id)
+        FAIL_PUTS_ERROR("unable to create test file\n");
+
+    dcpl_id = H5Pcreate(H5P_DATASET_CREATE);
+    if (0 > dcpl_id)
+        FAIL_PUTS_ERROR("unable to create DCPL\n");
+
+    /*********/
+    /* TESTS */
+    /*********/
+
+    /* default value (not set explicitly)
+     */
+    if (H5Pget_dset_no_attrs_hint(dcpl_id, &minimize) == FAIL)
+        FAIL_PUTS_ERROR("unable to get minimize value\n");
+    if (FALSE != minimize)
+        FAIL_PUTS_ERROR("Expected FALSE default but was not!\n");
+
+    /* FALSE-set value
+     */
+    if (H5Pset_dset_no_attrs_hint(dcpl_id, FALSE) == FAIL)
+        FAIL_PUTS_ERROR("unable to set minimize value to FALSE\n");
+    if (H5Pget_dset_no_attrs_hint(dcpl_id, &minimize) == FAIL)
+        FAIL_PUTS_ERROR("unable to get minimize value\n");
+    if (FALSE != minimize)
+        FAIL_PUTS_ERROR("Expected FALSE default but was not!\n");
+
+    /* TRUE-set value
+     */
+    if (H5Pset_dset_no_attrs_hint(dcpl_id, TRUE) == FAIL)
+        FAIL_PUTS_ERROR("unable to set minimize value to TRUE\n");
+    if (H5Pget_dset_no_attrs_hint(dcpl_id, &minimize) == FAIL)
+        FAIL_PUTS_ERROR("unable to get minimize value\n");
+    if (TRUE != minimize)
+        FAIL_PUTS_ERROR("Expected TRUE default but was not!\n");
+
+    /* error cases
+     */
+    H5E_BEGIN_TRY {
+        ret = H5Pget_dset_no_attrs_hint(-1, &minimize);
+    } H5E_END_TRY;
+    if (ret == SUCCEED)
+        FAIL_PUTS_ERROR("Invalid DCPL ID should fail\n");
+
+    H5E_BEGIN_TRY {
+        ret = H5Pset_dset_no_attrs_hint(-1, FALSE);
+    } H5E_END_TRY;
+    if (ret == SUCCEED)
+        FAIL_PUTS_ERROR("Invalid DCPL ID should fail\n");
+
+    H5E_BEGIN_TRY {
+        ret = H5Pset_dset_no_attrs_hint(-1, TRUE);
+    } H5E_END_TRY;
+    if (ret == SUCCEED)
+        FAIL_PUTS_ERROR("Invalid DCPL ID should fail\n");
+
+    H5E_BEGIN_TRY {
+        ret = H5Pget_dset_no_attrs_hint(dcpl_id, NULL);
+    } H5E_END_TRY;
+    if (ret == SUCCEED)
+        FAIL_PUTS_ERROR("NULL out pointer should fail\n");
+
+    /************/
+    /* TEARDOWN */
+    /************/
+
+    if (H5Fclose(file_id) == FAIL)
+        FAIL_PUTS_ERROR("can't close FILE");
+
+    if (H5Pclose(dcpl_id) == FAIL)
+        FAIL_PUTS_ERROR("unable to close DCPL\n");
+
+    PASSED();
+    return SUCCEED;
+
+error:
+    H5E_BEGIN_TRY {
+        H5Pclose(dcpl_id);
+        H5Fclose(file_id);
+    } H5E_END_TRY;
+    return FAIL;
+} /* end test_object_header_minimization_dcpl() */
 
 
 /*-------------------------------------------------------------------------
@@ -13068,6 +13180,7 @@ main(void)
     hid_t    fcpl = -1, fcpl2 = -1;
     unsigned new_format;
     unsigned paged;
+    unsigned minimized_ohdr;
     int      mdc_nelmts;
     size_t   rdcc_nelmts;
     size_t   rdcc_nbytes;
@@ -13118,10 +13231,12 @@ main(void)
     /* Test with paged aggregation enabled or not */
     for(paged = FALSE; paged <= TRUE; paged++) {
 
-        /* Temporary: skip testing for multi/split drivers:
-             fail file create when persisting free-space or using paged aggregation strategy */
-        if(!contig_addr_vfd && paged)
-            continue;
+      /* Temporary: skip testing for multi/split drivers:
+           fail file create when persisting free-space or using paged aggregation strategy */
+      if(!contig_addr_vfd && paged)
+          continue;
+
+      for (minimized_ohdr = FALSE; minimized_ohdr <= TRUE; minimized_ohdr++) {
 
         /* Test with old & new format groups */
         for(new_format = FALSE; new_format <= TRUE; new_format++) {
@@ -13153,6 +13268,12 @@ main(void)
             if((file = H5Fcreate(filename, H5F_ACC_TRUNC, my_fcpl, my_fapl)) < 0)
                 goto error;
 
+            if (TRUE == minimized_ohdr) {
+                if (0 > H5Fset_dset_no_attrs_hint(file, TRUE))
+                    goto error;
+                puts("(minimized dataset object headers with file setting)");
+            }
+
             /* Cause the library to emit initial messages */
             if((grp = H5Gcreate2(file, "emit diagnostics", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
                 goto error;
@@ -13230,6 +13351,7 @@ main(void)
             if(H5Fclose(file) < 0)
                 goto error;
         } /* end for new_format */
+      } /* for minimized dset object headers */
     } /* end for paged */
 
     /* Close property lists */
@@ -13246,6 +13368,8 @@ main(void)
     /* Tests version bounds using its own file */
     nerrors += (test_versionbounds() < 0             ? 1 : 0);
 
+    nerrors += (test_object_header_minimization_dcpl() < 0 ? 1 : 0);
+
     /* Run misc tests */
     nerrors += dls_01_main();
 
@@ -13261,12 +13385,12 @@ main(void)
 #endif /* H5_HAVE_FILTER_SZIP */
     h5_cleanup(FILENAME, fapl);
 
-    return 0;
+    return EXIT_SUCCESS;
 
 error:
     nerrors = MAX(1, nerrors);
     printf("***** %d DATASET TEST%s FAILED! *****\n",
             nerrors, 1 == nerrors ? "" : "S");
-    return 1;
-}
+    return EXIT_FAILURE;
+} /* end main() */
 
diff --git a/test/enc_dec_plist.c b/test/enc_dec_plist.c
index 36db2d0..33d23dc 100644
--- a/test/enc_dec_plist.c
+++ b/test/enc_dec_plist.c
@@ -146,6 +146,9 @@ main(void)
     if((H5Pset_fill_value(dcpl, H5T_NATIVE_DOUBLE, &fill)) < 0)
         FAIL_STACK_ERROR
 
+    if((H5Pset_dset_no_attrs_hint(dcpl, FALSE)) < 0)
+        FAIL_STACK_ERROR
+
     max_size[0] = 100;
     if((H5Pset_external(dcpl, "ext1.data", (off_t)0, 
                          (hsize_t)(max_size[0] * sizeof(int)/4))) < 0)
@@ -460,8 +463,6 @@ main(void)
         FAIL_STACK_ERROR
     if((H5Pset_mdc_image_config(fapl, &my_cache_image_config)) < 0)
         FAIL_STACK_ERROR
-    if((H5Pset_core_write_tracking(fapl, TRUE, 1024 * 1024)) < 0)
-        FAIL_STACK_ERROR
 
     /* Test encoding & decoding property list */
     if(test_encode_decode(fapl) < 0)
diff --git a/test/gen_plist.c b/test/gen_plist.c
index 62693bd..68da6cc 100644
--- a/test/gen_plist.c
+++ b/test/gen_plist.c
@@ -125,6 +125,9 @@ main(void)
     if((ret = H5Pset_fill_value(dcpl1, H5T_STD_I32BE, &fill)) < 0)
         assert(ret > 0);
 
+    if((ret = H5Pset_dset_no_attrs_hint(dcpl1, FALSE)) < 0)
+        assert(ret > 0);
+
     max_size[0] = 100;
     if((ret = H5Pset_external(dcpl1, "ext1.data", (off_t)0, 
                          (hsize_t)(max_size[0] * sizeof(int)/4))) < 0)
@@ -363,9 +366,6 @@ main(void)
     if((ret = H5Pset_mdc_image_config(fapl1, &my_cache_image_config)) < 0)
         assert(ret > 0);
 
-    if((ret = H5Pset_core_write_tracking(fapl1, TRUE, (size_t)(1024 * 1024))) < 0)
-        assert(ret > 0);
-
     if((ret = encode_plist(fapl1, little_endian, word_length, "testfiles/plist_files/fapl_")) < 0)
         assert(ret > 0);
 
@@ -476,7 +476,7 @@ encode_plist(hid_t plist_id, int little_endian, int word_length, const char *fil
         HDassert(ret > 0);
 
     fd = HDopen(filename, O_RDWR | O_CREAT | O_TRUNC, H5_POSIX_CREATE_MODE_RW);
-    HDassert(fd > 0);
+    HDassert(fd >= 0);
 
     write_size = HDwrite(fd, temp_buf, temp_size);
     HDassert(write_size == (ssize_t)temp_size);
diff --git a/test/h5test.c b/test/h5test.c
index 6aad76a..32638e6 100644
--- a/test/h5test.c
+++ b/test/h5test.c
@@ -158,47 +158,8 @@ h5_clean_files(const char *base_name[], hid_t fapl)
     int i;
 
     for(i = 0; base_name[i]; i++) {
-        char filename[1024];
-        char temp[2048];
-        hid_t driver;
-
-        if(NULL == h5_fixname(base_name[i], fapl, filename, sizeof(filename)))
-            continue;
-
-        driver = H5Pget_driver(fapl);
-
-        if(driver == H5FD_FAMILY) {
-            int j;
-
-            for(j = 0; /*void*/; j++) {
-                HDsnprintf(temp, sizeof temp, filename, j);
-
-                if(HDaccess(temp, F_OK) < 0)
-                    break;
-
-                HDremove(temp);
-            } /* end for */
-        } else if(driver == H5FD_CORE) {
-            hbool_t backing;        /* Whether the core file has backing store */
-
-            H5Pget_fapl_core(fapl, NULL, &backing);
-
-            /* If the file was stored to disk with bacing store, remove it */
-            if(backing)
-                HDremove(filename);
-        } else if (driver == H5FD_MULTI) {
-            H5FD_mem_t mt;
-
-            HDassert(HDstrlen(multi_letters)==H5FD_MEM_NTYPES);
-
-            for(mt = H5FD_MEM_DEFAULT; mt < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t,mt)) {
-                HDsnprintf(temp, sizeof temp, "%s-%c.h5", filename, multi_letters[mt]);
-                HDremove(temp); /*don't care if it fails*/
-            } /* end for */
-        } else {
-            HDremove(filename);
-        }
-    } /* end for */
+        h5_delete_test_file(base_name[i], fapl);
+    }
 
     /* Close the FAPL used to access the file */
     H5Pclose(fapl);
@@ -266,10 +227,10 @@ h5_delete_test_file(const char *base_name, hid_t fapl)
         for(mt = H5FD_MEM_DEFAULT; mt < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t,mt)) {
             HDsnprintf(sub_filename, sizeof(sub_filename), "%s-%c.h5", filename, multi_letters[mt]);
             HDremove(sub_filename);
-        } /* end for */
+        }
     } else {
         HDremove(filename);
-    } /* end if */
+    } /* end driver selection tree */
 
     return;
 } /* end h5_delete_test_file() */
@@ -652,7 +613,7 @@ h5_fixname_real(const char *base_name, hid_t fapl, const char *_suffix,
                 printf("*** Hint ***\n"
                        "You can use environment variable HDF5_PARAPREFIX to "
                        "run parallel test files in a\n"
-                       "different directory or to add file type prefix. E.g.,\n"
+                       "different directory or to add file type prefix. e.g.,\n"
                        "   HDF5_PARAPREFIX=pfs:/PFS/user/me\n"
                        "   export HDF5_PARAPREFIX\n"
                        "*** End of Hint ***\n");
@@ -802,10 +763,10 @@ h5_rmprefix(const char *filename)
  *
  * Purpose:     Returns a file access template which is the default template
  *              but with a file driver, VOL connector, or libver bound set
- *		according to a constant or environment variable
+ *              according to a constant or environment variable
  *
- * Return:      Success:  A file access property list
- *              Failure:  -1
+ * Return:      Success:    A file access property list
+ *              Failure:    H5I_INVALID_HID
  *
  * Programmer:  Robb Matzke
  *              Thursday, November 19, 1998
@@ -815,24 +776,29 @@ h5_rmprefix(const char *filename)
 hid_t
 h5_fileaccess(void)
 {
-    hid_t       fapl = -1;
+    hid_t       fapl_id = H5I_INVALID_HID;
 
-    if((fapl = H5Pcreate(H5P_FILE_ACCESS)) < 0)
-        return -1;
+    if((fapl_id = H5Pcreate(H5P_FILE_ACCESS)) < 0)
+        goto error;
 
     /* Attempt to set up a file driver first */
-    if(h5_get_vfd_fapl(fapl) < 0)
-         return -1;
+    if(h5_get_vfd_fapl(fapl_id) < 0)
+        goto error;
 
     /* Next, try to set up a VOL connector */
-    if(h5_get_vol_fapl(fapl) < 0)
-        return -1;
+    if(h5_get_vol_fapl(fapl_id) < 0)
+        goto error;
  
     /* Finally, check for libver bounds */
-    if(h5_get_libver_fapl(fapl) < 0)
-        return -1;
+    if(h5_get_libver_fapl(fapl_id) < 0)
+        goto error;
  
-    return(fapl);
+    return fapl_id;
+
+error:
+    if(fapl_id != H5I_INVALID_HID)
+        H5Pclose(fapl_id);
+    return H5I_INVALID_HID;
 } /* end h5_fileaccess() */
 
 
@@ -891,11 +857,11 @@ h5_get_vfd_fapl(hid_t fapl)
             goto error;
     } else if(!HDstrcmp(tok, "core")) {
         /* In-memory driver settings (backing store on, 1 MB increment) */
-        if(H5Pset_fapl_core(fapl, (size_t)1, TRUE) < 0)
+        if(H5Pset_fapl_core(fapl, (size_t)H5_MB, TRUE) < 0)
             goto error;
     } else if(!HDstrcmp(tok, "core_paged")) {
         /* In-memory driver with write tracking and paging on */
-        if(H5Pset_fapl_core(fapl, (size_t)1, TRUE) < 0)
+        if(H5Pset_fapl_core(fapl, (size_t)H5_MB, TRUE) < 0)
             goto error;
         if(H5Pset_core_write_tracking(fapl, TRUE, (size_t)4096) < 0)
             goto error;
@@ -1042,7 +1008,7 @@ error:
  *              fapl but with a VOL connector set according to the constant
  *              or environment variable HDF5_VOL_CONNECTOR.
  *
- * Return:      Success:    A file access property list ID
+ * Return:      Success:    0
  *              Failure:    -1
  *
  * Programmer:  Jordan Henderson
diff --git a/test/links.c b/test/links.c
index b10d0ad..b09ddb1 100644
--- a/test/links.c
+++ b/test/links.c
@@ -315,6 +315,8 @@ typedef struct {
     const obj_visit_t *info;    /* Pointer to the object visit structure to use */
 } ovisit_ud_t;
 
+static hid_t dcpl_g; /* for [un]minimized dataset object headers */
+
 
 
 /*-------------------------------------------------------------------------
@@ -377,7 +379,7 @@ mklinks(hid_t fapl, hbool_t new_format)
     if(H5Gclose(grp) < 0) TEST_ERROR
 
     /* Create a dataset */
-    if((d1 = H5Dcreate2(file, "d1", H5T_NATIVE_INT, scalar, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if((d1 = H5Dcreate2(file, "d1", H5T_NATIVE_INT, scalar, H5P_DEFAULT, dcpl_g, H5P_DEFAULT)) < 0) TEST_ERROR
     if(H5Dclose(d1) < 0) TEST_ERROR
 
     /* Create a hard link */
@@ -451,8 +453,8 @@ new_links(hid_t fapl, hbool_t new_format)
     if((grp2_b = H5Gcreate2(file_b, "grp2", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
 
     /* Create datasets */
-    if((dset1 = H5Dcreate2(file_a, "dataset1", H5T_NATIVE_INT, scalar, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
-    if((dset2 = H5Dcreate2(grp1_a, "dataset2", H5T_NATIVE_INT, scalar, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if((dset1 = H5Dcreate2(file_a, "dataset1", H5T_NATIVE_INT, scalar, H5P_DEFAULT, dcpl_g, H5P_DEFAULT)) < 0) TEST_ERROR
+    if((dset2 = H5Dcreate2(grp1_a, "dataset2", H5T_NATIVE_INT, scalar, H5P_DEFAULT, dcpl_g, H5P_DEFAULT)) < 0) TEST_ERROR
 
     /* Create links within a file.  Both of source and destination use
      * H5L_SAME_LOC.  Both hard and soft links should fail. */
@@ -545,7 +547,7 @@ cklinks(hid_t fapl, hbool_t new_format)
     if(H5Oget_info_by_name2(file, "grp1/hard", &oinfo2, H5O_INFO_BASIC, H5P_DEFAULT) < 0) FAIL_STACK_ERROR
     if(H5O_TYPE_DATASET != oinfo2.type) {
 	H5_FAILED();
-	printf("    %d: Unexpected object type should have been a dataset\n", __LINE__);
+	HDprintf("    %d: Unexpected object type should have been a dataset\n", __LINE__);
 	TEST_ERROR
     } /* end if */
     if(H5F_addr_ne(oinfo1.addr, oinfo2.addr)) {
@@ -580,7 +582,7 @@ cklinks(hid_t fapl, hbool_t new_format)
     if(H5Oget_info_by_name2(file, "grp1/soft", &oinfo2, H5O_INFO_BASIC, H5P_DEFAULT) < 0) FAIL_STACK_ERROR
     if(H5O_TYPE_DATASET != oinfo2.type) {
 	H5_FAILED();
-	printf("    %d: Unexpected object type should have been a dataset\n", __LINE__);
+	HDprintf("    %d: Unexpected object type should have been a dataset\n", __LINE__);
 	TEST_ERROR
     } /* end if */
     if(H5F_addr_ne(oinfo1.addr, oinfo2.addr)) {
@@ -609,12 +611,12 @@ cklinks(hid_t fapl, hbool_t new_format)
     if(H5Lget_info(file, "grp1/dangle", &linfo2, H5P_DEFAULT) < 0) FAIL_STACK_ERROR
     if(H5L_TYPE_SOFT != linfo2.type) {
 	H5_FAILED();
-	printf("    %d: Unexpected object type should have been a symbolic link\n", __LINE__);
+	HDprintf("    %d: Unexpected object type should have been a symbolic link\n", __LINE__);
 	TEST_ERROR
     } /* end if */
     if(H5Lget_val(file, "grp1/dangle", linkval, sizeof linkval, H5P_DEFAULT) < 0) {
 	H5_FAILED();
-	printf("    %d: Can't retrieve link value\n", __LINE__);
+	HDprintf("    %d: Can't retrieve link value\n", __LINE__);
 	TEST_ERROR
     } /* end if */
     if(HDstrcmp(linkval, "foobar")) {
@@ -636,12 +638,12 @@ cklinks(hid_t fapl, hbool_t new_format)
     if(H5Lget_info(file, "grp1/recursive", &linfo2, H5P_DEFAULT) < 0) FAIL_STACK_ERROR
     if(H5L_TYPE_SOFT != linfo2.type) {
 	H5_FAILED();
-	printf("    %d: Unexpected object type should have been a symbolic link\n", __LINE__);
+	HDprintf("    %d: Unexpected object type should have been a symbolic link\n", __LINE__);
 	TEST_ERROR
     } /* end if */
     if(H5Lget_val(file, "grp1/recursive", linkval, sizeof linkval, H5P_DEFAULT) < 0) {
 	H5_FAILED();
-	printf("    %d: Can't retrieve link value\n", __LINE__);
+	HDprintf("    %d: Can't retrieve link value\n", __LINE__);
 	TEST_ERROR
     } /* end if */
     if(HDstrcmp(linkval, "/grp1/recursive")) {
@@ -706,7 +708,7 @@ ck_new_links(hid_t fapl, hbool_t new_format)
     /* Check hard links */
     if(H5O_TYPE_DATASET != oi_hard1.type || H5O_TYPE_DATASET != oi_hard2.type) {
 	H5_FAILED();
-	printf("    %d: Unexpected object type should have been a dataset\n", __LINE__);
+	HDprintf("    %d: Unexpected object type should have been a dataset\n", __LINE__);
 	TEST_ERROR
     }
     if(H5F_addr_ne(oi_dset.addr, oi_hard1.addr) || H5F_addr_ne(oi_dset.addr, oi_hard2.addr)) {
@@ -1014,7 +1016,7 @@ test_lcpl(hid_t fapl, hbool_t new_format)
     if((space_id=H5Screate_simple(2 ,dims, NULL)) < 0) TEST_ERROR
 
     /* Create a dataset using the default LCPL */
-    if((dset_id = H5Dcreate2(file_id, "/dataset", H5T_NATIVE_INT, space_id, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if((dset_id = H5Dcreate2(file_id, "/dataset", H5T_NATIVE_INT, space_id, H5P_DEFAULT, dcpl_g, H5P_DEFAULT)) < 0) TEST_ERROR
     if(H5Dclose(dset_id) < 0) TEST_ERROR
 
     /* Check that its character encoding is the default */
@@ -1043,7 +1045,7 @@ test_lcpl(hid_t fapl, hbool_t new_format)
     if(linfo.cset != H5T_CSET_UTF8) TEST_ERROR
 
     /* Create a dataset using the new LCPL */
-    if((dset_id = H5Dcreate2(file_id, "/dataset2", H5T_NATIVE_INT, space_id, lcpl_id, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if((dset_id = H5Dcreate2(file_id, "/dataset2", H5T_NATIVE_INT, space_id, lcpl_id, dcpl_g, H5P_DEFAULT)) < 0) TEST_ERROR
     if(H5Dclose(dset_id) < 0) TEST_ERROR
 
     /* Check that its character encoding is UTF-8 */
@@ -2602,7 +2604,7 @@ external_link_toomany(hid_t fapl, hbool_t new_format)
     } H5E_END_TRY;
     if (gid >= 0) {
 	H5_FAILED();
-	printf("%d:    Should have failed for sequence of too many nested links.", __LINE__);
+	HDprintf("%d:    Should have failed for sequence of too many nested links.", __LINE__);
 	goto error;
     }
 
@@ -3758,7 +3760,11 @@ external_set_elink_fapl2(hid_t fapl, hbool_t new_format)
     if((space = H5Screate_simple(2, dims, NULL)) < 0) TEST_ERROR
 
     /* Create dataset creation property list */
-    if((dcpl = H5Pcreate(H5P_DATASET_CREATE)) < 0) TEST_ERROR;
+    if (dcpl_g == H5P_DEFAULT)
+        dcpl = H5Pcreate(H5P_DATASET_CREATE);
+    else
+        dcpl = H5Pcopy(dcpl_g);
+    if (0 > dcpl) TEST_ERROR;
     if(H5Pset_alloc_time(dcpl, H5D_ALLOC_TIME_LATE) < 0) TEST_ERROR;
 
     /* create "Dataset" in group "A" of target file */
@@ -6100,7 +6106,7 @@ external_link_closing(hid_t fapl, hbool_t new_format)
     /* Test creating each kind of object */
     if((gid = H5Gcreate2(fid1, "elink/elink/elink/group1", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
     if(H5Tcommit2(fid1, "elink/elink/elink/type1", tid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
-    if((did = H5Dcreate2(fid1, "elink/elink/elink/dataset1", tid2, sid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if((did = H5Dcreate2(fid1, "elink/elink/elink/dataset1", tid2, sid, H5P_DEFAULT, dcpl_g, H5P_DEFAULT)) < 0) TEST_ERROR
 
     /* Close objects */
     if(H5Gclose(gid) < 0) TEST_ERROR
@@ -7298,7 +7304,7 @@ external_open_twice(hid_t fapl, hbool_t new_format)
     if((space = H5Screate(H5S_SCALAR)) < 0)
         TEST_ERROR
     if((oid1 = H5Dcreate2(fid2, "dset", H5T_NATIVE_INT, space, H5P_DEFAULT,
-            H5P_DEFAULT, H5P_DEFAULT)) < 0)
+            dcpl_g, H5P_DEFAULT)) < 0)
         TEST_ERROR
     if(H5Dclose(oid1) < 0)
         TEST_ERROR
@@ -7514,8 +7520,11 @@ external_link_with_committed_datatype(hid_t fapl, hbool_t new_format)
     if((sid2 = H5Screate_simple(2, dims, NULL)) < 0)
         FAIL_STACK_ERROR
 
-    if((dcpl = H5Pcreate(H5P_DATASET_CREATE)) < 0)
-        FAIL_STACK_ERROR
+    if (dcpl_g == H5P_DEFAULT)
+        dcpl = H5Pcreate(H5P_DATASET_CREATE);
+    else
+        dcpl = H5Pcopy(dcpl_g);
+    if (0 > dcpl) FAIL_STACK_ERROR
     if(H5Pset_chunk(dcpl, 2, chunks) < 0)
         FAIL_STACK_ERROR
 
@@ -9058,7 +9067,7 @@ lapl_nlinks(hid_t fapl, hbool_t new_format)
     dims[0] = 2;
     dims[1] = 2;
     if((sid = H5Screate_simple(2, dims, NULL)) < 0) TEST_ERROR
-    if((did = H5Dcreate2(gid, "dataset", H5T_NATIVE_INT, sid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if((did = H5Dcreate2(gid, "dataset", H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl_g, H5P_DEFAULT)) < 0) TEST_ERROR
     if(H5Dclose(did) < 0) TEST_ERROR
 
     /* Close group */
@@ -9170,7 +9179,7 @@ linkinfo(hid_t fapl, hbool_t new_format)
     if(H5Lcreate_soft("group", fid, "softlink", H5P_DEFAULT, H5P_DEFAULT) < 0) FAIL_STACK_ERROR
 
     if((sid = H5Screate(H5S_SCALAR)) < 0) TEST_ERROR
-    if((did = H5Dcreate2(fid, "dataset", H5T_NATIVE_INT, sid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if((did = H5Dcreate2(fid, "dataset", H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl_g, H5P_DEFAULT)) < 0) TEST_ERROR
 
     if(H5Lcreate_ud(fid, "ud_link", (H5L_type_t)UD_PLIST_TYPE, NULL, (size_t)0, H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
     if(H5Lcreate_external("file_name", "obj_path", fid, "ext_link", H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
@@ -9335,13 +9344,13 @@ build_visit_file(hid_t fapl)
     /* Create dataset in each group */
     if((sid = H5Screate(H5S_SCALAR)) < 0) TEST_ERROR
 
-    if((did = H5Dcreate2(fid, "/Dataset_zero", H5T_NATIVE_INT, sid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if((did = H5Dcreate2(fid, "/Dataset_zero", H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl_g, H5P_DEFAULT)) < 0) TEST_ERROR
     if(H5Dclose(did) < 0) TEST_ERROR
 
-    if((did = H5Dcreate2(fid, "/Group1/Dataset_one", H5T_NATIVE_INT, sid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if((did = H5Dcreate2(fid, "/Group1/Dataset_one", H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl_g, H5P_DEFAULT)) < 0) TEST_ERROR
     if(H5Dclose(did) < 0) TEST_ERROR
 
-    if((did = H5Dcreate2(fid, "/Group1/Group2/Dataset_two", H5T_NATIVE_INT, sid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if((did = H5Dcreate2(fid, "/Group1/Group2/Dataset_two", H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl_g, H5P_DEFAULT)) < 0) TEST_ERROR
     if(H5Dclose(did) < 0) TEST_ERROR
 
     if(H5Sclose(sid) < 0) TEST_ERROR
@@ -14890,6 +14899,7 @@ main(void)
     hid_t	fapl, fapl2;    /* File access property lists */
     int	nerrors = 0;
     unsigned new_format;    /* Whether to use the new format or not */
+    unsigned minimize_dset_oh;
     unsigned efc;           /* Whether to use the external file cache */
     const char  *env_h5_drvr;      /* File Driver value from environment */
 
@@ -14900,165 +14910,187 @@ main(void)
     h5_reset();
     fapl = h5_fileaccess();
 
-    /* Copy the file access property list */
+    /* fapl2 uses "latest version bounds" */
     if((fapl2 = H5Pcopy(fapl)) < 0) TEST_ERROR
-
-    /* Set the "use the latest version of the format" bounds for creating objects in the file */
     if(H5Pset_libver_bounds(fapl2, H5F_LIBVER_LATEST, H5F_LIBVER_LATEST) < 0) TEST_ERROR
 
-    /* Loop over using new group format */
-    for(new_format = FALSE; new_format <= TRUE; new_format++) {
-        hid_t my_fapl;
+    for (minimize_dset_oh = 0; minimize_dset_oh <= 1; minimize_dset_oh++) {
+        if (minimize_dset_oh) {
+            HDprintf("\n-Testing with minimzed dataset object headers-\n");
+            dcpl_g = H5Pcreate(H5P_DATASET_CREATE);
+            if (0 > dcpl_g) TEST_ERROR
+        } else {
+            HDprintf("\n-Testing with unminimzed dataset object headers-\n");
+            dcpl_g = H5P_DEFAULT;
+        }
 
-        /* Check for FAPL to use */
-        if(new_format)
-            my_fapl = fapl2;
-        else
-            my_fapl = fapl;
-
-        /* General tests... (on both old & new format groups */
-        nerrors += mklinks(my_fapl, new_format) < 0 ? 1 : 0;
-        nerrors += cklinks(my_fapl, new_format) < 0 ? 1 : 0;
-        nerrors += new_links(my_fapl, new_format) < 0 ? 1 : 0;
-        nerrors += ck_new_links(my_fapl, new_format) < 0 ? 1 : 0;
-        nerrors += long_links(my_fapl, new_format) < 0 ? 1 : 0;
-        nerrors += toomany(my_fapl, new_format) < 0 ? 1 : 0;
-
-        /* Test new H5L link creation routine */
-        nerrors += test_lcpl(my_fapl, new_format);
-        nerrors += test_move(my_fapl, new_format);
-        nerrors += test_copy(my_fapl, new_format);
-        nerrors += test_move_preserves(my_fapl, new_format);
+        for(new_format = FALSE; new_format <= TRUE; new_format++) {
+            hid_t my_fapl;
+
+            /* Check for FAPL to use */
+            if(new_format) {
+                my_fapl = fapl2;
+                HDprintf("\n--Testing with 'new format'--\n");
+            } else {
+                my_fapl = fapl;
+                HDprintf("\n--Testing with 'old format'--\n");
+            }
+
+            /* always enter tests without external cache */
+            if(H5Pset_elink_file_cache_size(my_fapl, 0) < 0)
+                TEST_ERROR
+
+            /* General tests... (on both old & new format groups */
+            nerrors += mklinks(my_fapl, new_format) < 0 ? 1 : 0;
+            nerrors += cklinks(my_fapl, new_format) < 0 ? 1 : 0;
+            nerrors += new_links(my_fapl, new_format) < 0 ? 1 : 0;
+            nerrors += ck_new_links(my_fapl, new_format) < 0 ? 1 : 0;
+            nerrors += long_links(my_fapl, new_format) < 0 ? 1 : 0;
+            nerrors += toomany(my_fapl, new_format) < 0 ? 1 : 0;
+
+            /* Test new H5L link creation routine */
+            nerrors += test_lcpl(my_fapl, new_format);
+            nerrors += test_move(my_fapl, new_format);
+            nerrors += test_copy(my_fapl, new_format);
+            nerrors += test_move_preserves(my_fapl, new_format);
 #ifndef H5_NO_DEPRECATED_SYMBOLS
-        nerrors += test_deprec(my_fapl, new_format);
+            nerrors += test_deprec(my_fapl, new_format);
 #endif /* H5_NO_DEPRECATED_SYMBOLS */
 
-        /* tests for external link */
-        /* Test external file cache first, so it sees the default efc setting on
-         * the fapl */
-        nerrors += external_file_cache(my_fapl, new_format) < 0 ? 1 : 0;
-
-        /* This test cannot run with the EFC because it assumes that an
-         * intermediate file is not held open */
-        nerrors += external_link_mult(my_fapl, new_format) < 0 ? 1 : 0;
-
-        /* This test cannot run with the EFC because the EFC cannot currently
-         * reopen a cached file with a different intent */
-        nerrors += external_set_elink_acc_flags(env_h5_drvr, my_fapl, new_format) < 0 ? 1 : 0;
-
-        /* Try external link tests both with and without the external file cache
-         */
-        for(efc = FALSE; efc <= TRUE; efc++) {
-            if(efc) {
-                if(H5Pset_elink_file_cache_size(my_fapl, 8) < 0)
-                    TEST_ERROR
-                printf("\n---Testing with external file cache---\n");
-            } /* end if */
-            else {
-                if(H5Pset_elink_file_cache_size(my_fapl, 0) < 0)
-                    TEST_ERROR
-                printf("\n---Testing without external file cache---\n");
-            } /* end else */
+            /* tests for external link */
+            /* Test external file cache first, so it sees the default efc setting on
+             * the fapl */
+            nerrors += external_file_cache(my_fapl, new_format) < 0 ? 1 : 0;
+
+            /* This test cannot run with the EFC because it assumes that an
+             * intermediate file is not held open */
+            nerrors += external_link_mult(my_fapl, new_format) < 0 ? 1 : 0;
+
+            /* This test cannot run with the EFC because the EFC cannot currently
+             * reopen a cached file with a different intent */
+            nerrors += external_set_elink_acc_flags(env_h5_drvr, my_fapl, new_format) < 0 ? 1 : 0;
+
+            /* Try external link tests both with and without the external file cache
+             */
+            for(efc = FALSE; efc <= TRUE; efc++) {
+                if(efc) {
+                    if(H5Pset_elink_file_cache_size(my_fapl, 8) < 0)
+                        TEST_ERROR
+                    HDprintf("\n---Testing with external file cache---\n");
+                } /* end if */
+                else {
+                    if(H5Pset_elink_file_cache_size(my_fapl, 0) < 0)
+                        TEST_ERROR
+                    HDprintf("\n---Testing without external file cache---\n");
+                } /* end else */
 
-            nerrors += external_link_root(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_path(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_self(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_pingpong(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_toomany(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_dangling(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_recursive(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_query(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_unlink_compact(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_unlink_dense(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_move(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_ride(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_closing(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_endian(new_format) < 0 ? 1 : 0;
-            nerrors += external_link_strong(my_fapl, new_format) < 0 ? 1 : 0;
-
-            nerrors += external_link_prefix(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_abs_mainpath(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_rel_mainpath(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_cwd(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_abstar(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_abstar_cur(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_reltar(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_chdir(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_set_elink_fapl1(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_set_elink_fapl2(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_set_elink_fapl3(new_format) < 0 ? 1 : 0;
-            nerrors += external_set_elink_cb(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_root(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_path(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_self(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_pingpong(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_toomany(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_dangling(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_recursive(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_query(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_unlink_compact(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_unlink_dense(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_move(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_ride(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_closing(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_endian(new_format) < 0 ? 1 : 0;
+                nerrors += external_link_strong(my_fapl, new_format) < 0 ? 1 : 0;
+
+                nerrors += external_link_prefix(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_abs_mainpath(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_rel_mainpath(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_cwd(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_abstar(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_abstar_cur(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_reltar(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_chdir(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_set_elink_fapl1(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_set_elink_fapl2(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_set_elink_fapl3(new_format) < 0 ? 1 : 0;
+                nerrors += external_set_elink_cb(my_fapl, new_format) < 0 ? 1 : 0;
 #ifdef H5_HAVE_WINDOW_PATH
-            nerrors += external_link_win1(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_win2(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_win3(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_win4(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_win5(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_win6(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_win7(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_win8(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_win9(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_win1(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_win2(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_win3(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_win4(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_win5(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_win6(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_win7(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_win8(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_link_win9(my_fapl, new_format) < 0 ? 1 : 0;
 #endif
-            nerrors += external_symlink(env_h5_drvr, my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_copy_invalid_object(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_dont_fail_to_source(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_open_twice(my_fapl, new_format) < 0 ? 1 : 0;
-            nerrors += external_link_with_committed_datatype(my_fapl, new_format) < 0 ? 1 : 0;
-        } /* end for */
-
-        /* These tests assume that external links are a form of UD links,
-         * so assume that everything that passed for external links
-         * above has already been tested for UD links.
-         */
-        if(new_format == TRUE) {
-            nerrors += ud_hard_links(fapl2) < 0 ? 1 : 0;     /* requires new format groups */
-            nerrors += ud_link_reregister(fapl2) < 0 ? 1 : 0;        /* requires new format groups */
-        } /* end if */
-        nerrors += ud_callbacks(my_fapl, new_format) < 0 ? 1 : 0;
-        nerrors += ud_link_errors(my_fapl, new_format) < 0 ? 1 : 0;
-        nerrors += lapl_udata(my_fapl, new_format) < 0 ? 1 : 0;
-        nerrors += lapl_nlinks(my_fapl, new_format) < 0 ? 1 : 0;
-        nerrors += linkinfo(my_fapl, new_format) < 0 ? 1 : 0;
-
-        /* Misc. extra tests, useful for both new & old format files */
-        nerrors += link_visit(my_fapl, new_format) < 0 ? 1 : 0;
-        nerrors += link_visit_by_name(my_fapl, new_format) < 0 ? 1 : 0;
-        nerrors += obj_visit(my_fapl, new_format) < 0 ? 1 : 0;
-        nerrors += obj_visit_by_name(my_fapl, new_format) < 0 ? 1 : 0;
-        nerrors += obj_visit_stop(my_fapl, new_format) < 0 ? 1 : 0;
-        nerrors += link_filters(my_fapl, new_format) < 0 ? 1 : 0;
-        nerrors += obj_exists(my_fapl, new_format) < 0 ? 1 : 0;
-
-        /* Keep this test last, it's testing files that are used above */
-        /* do not do this for files used by external link tests */
-        nerrors += check_all_closed(my_fapl, new_format, EXTSTOP) < 0 ? 1 : 0;
-    } /* end for */
+                nerrors += external_symlink(env_h5_drvr, my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_copy_invalid_object(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_dont_fail_to_source(my_fapl, new_format) < 0 ? 1 : 0;
+                nerrors += external_open_twice(my_fapl, new_format) < 0 ? 1 : 0;
+	        nerrors += external_link_with_committed_datatype(my_fapl, new_format) < 0 ? 1 : 0;
+            } /* with/without external file cache */
+
+            /* These tests assume that external links are a form of UD links,
+             * so assume that everything that passed for external links
+             * above has already been tested for UD links.
+             */
+            if(new_format == TRUE) {
+                nerrors += ud_hard_links(fapl2) < 0 ? 1 : 0;     /* requires new format groups */
+                nerrors += ud_link_reregister(fapl2) < 0 ? 1 : 0;        /* requires new format groups */
+            } /* end if */
+            nerrors += ud_callbacks(my_fapl, new_format) < 0 ? 1 : 0;
+            nerrors += ud_link_errors(my_fapl, new_format) < 0 ? 1 : 0;
+            nerrors += lapl_udata(my_fapl, new_format) < 0 ? 1 : 0;
+            nerrors += lapl_nlinks(my_fapl, new_format) < 0 ? 1 : 0;
+            nerrors += linkinfo(my_fapl, new_format) < 0 ? 1 : 0;
+
+            /* Misc. extra tests, useful for both new & old format files */
+            nerrors += link_visit(my_fapl, new_format) < 0 ? 1 : 0;
+            nerrors += link_visit_by_name(my_fapl, new_format) < 0 ? 1 : 0;
+            nerrors += obj_visit(my_fapl, new_format) < 0 ? 1 : 0;
+            nerrors += obj_visit_by_name(my_fapl, new_format) < 0 ? 1 : 0;
+            nerrors += obj_visit_stop(my_fapl, new_format) < 0 ? 1 : 0;
+            nerrors += link_filters(my_fapl, new_format) < 0 ? 1 : 0;
+            nerrors += obj_exists(my_fapl, new_format) < 0 ? 1 : 0;
+
+            /* Keep this test last, it's testing files that are used above */
+            /* do not do this for files used by external link tests */
+            nerrors += check_all_closed(my_fapl, new_format, EXTSTOP) < 0 ? 1 : 0;
+        } /* new/old format */
+
+        /* New group revision feature tests */
+        nerrors += corder_create_empty(fapl2) < 0 ? 1 : 0;
 
-    /* New group revision feature tests */
-    nerrors += corder_create_empty(fapl2) < 0 ? 1 : 0;
 /* XXX: when creation order indexing is fully working, go back and add checks
 *      to these tests to make certain that the creation order values are
 *      correct.
 */
-    nerrors += corder_create_compact(fapl2) < 0 ? 1 : 0;
-    nerrors += corder_create_dense(fapl2) < 0 ? 1 : 0;
-    nerrors += corder_transition(fapl2) < 0 ? 1 : 0;
-    nerrors += corder_delete(fapl2) < 0 ? 1 : 0;
-    nerrors += link_info_by_idx(fapl2) < 0 ? 1 : 0;
-    nerrors += delete_by_idx(fapl2) < 0 ? 1 : 0;
-    nerrors += link_iterate(fapl2) < 0 ? 1 : 0;
-    nerrors += open_by_idx(fapl2) < 0 ? 1 : 0;
-    nerrors += object_info(fapl2) < 0 ? 1 : 0;
-    nerrors += group_info(fapl2) < 0 ? 1 : 0;
-    nerrors += timestamps(fapl2) < 0 ? 1 : 0;
-
-    /* Test new API calls on old-style groups */
-    nerrors += link_info_by_idx_old(fapl) < 0 ? 1 : 0;
-    nerrors += delete_by_idx_old(fapl) < 0 ? 1 : 0;
-    nerrors += link_iterate_old(fapl) < 0 ? 1 : 0;
-    nerrors += open_by_idx_old(fapl) < 0 ? 1 : 0;
-    nerrors += object_info_old(fapl) < 0 ? 1 : 0;
-    nerrors += group_info_old(fapl) < 0 ? 1 : 0;
+        nerrors += corder_create_compact(fapl2) < 0 ? 1 : 0;
+        nerrors += corder_create_dense(fapl2) < 0 ? 1 : 0;
+        nerrors += corder_transition(fapl2) < 0 ? 1 : 0;
+        nerrors += corder_delete(fapl2) < 0 ? 1 : 0;
+        nerrors += link_info_by_idx(fapl2) < 0 ? 1 : 0;
+        nerrors += delete_by_idx(fapl2) < 0 ? 1 : 0;
+        nerrors += link_iterate(fapl2) < 0 ? 1 : 0;
+        nerrors += open_by_idx(fapl2) < 0 ? 1 : 0;
+        nerrors += object_info(fapl2) < 0 ? 1 : 0;
+        nerrors += group_info(fapl2) < 0 ? 1 : 0;
+        nerrors += timestamps(fapl2) < 0 ? 1 : 0;
+
+        /* Test new API calls on old-style groups */
+        nerrors += link_info_by_idx_old(fapl) < 0 ? 1 : 0;
+        nerrors += delete_by_idx_old(fapl) < 0 ? 1 : 0;
+        nerrors += link_iterate_old(fapl) < 0 ? 1 : 0;
+        nerrors += open_by_idx_old(fapl) < 0 ? 1 : 0;
+        nerrors += object_info_old(fapl) < 0 ? 1 : 0;
+        nerrors += group_info_old(fapl) < 0 ? 1 : 0;
+
+        if (minimize_dset_oh) {
+            if (H5Pclose(dcpl_g) < 0)
+                TEST_ERROR;
+            dcpl_g = -1;
+        }
+    } /* [un]minimized dataset object headers */
 
     /* Close 2nd FAPL */
     H5Pclose(fapl2);
@@ -15075,11 +15107,11 @@ main(void)
 
     /* Results */
     if(nerrors) {
-        printf("***** %d LINK TEST%s FAILED! *****\n",
+        HDprintf("***** %d LINK TEST%s FAILED! *****\n",
                 nerrors, 1 == nerrors ? "" : "S");
         HDexit(EXIT_FAILURE);
     }
-    printf("All link tests passed.\n");
+    HDprintf("All link tests passed.\n");
 
     /* clean up symlink created by external link tests */
     HDremove(SYMLINK1);
diff --git a/test/echo_vol.c b/test/null_vol_connector.c
index 7f59832..b62b370 100644
--- a/test/echo_vol.c
+++ b/test/null_vol_connector.c
@@ -10,19 +10,20 @@
  * help@hdfgroup.org.                                                        *
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-/*
- * Purpose:     A simple virtual object layer (VOL) plugin that just echoes
- *              the name of the API call.
+/* Purpose:     A simple virtual object layer (VOL) connector with almost no
+ *              functionality that is used for testing basic plugin handling
+ *              (registration, etc.).
  */
 
 #include "H5PLextern.h"
 
-/* The VOL class struct.
- */
-static const H5VL_class_t echo_vol_g = {
+#include "null_vol_connector.h"
+
+/* The VOL class struct */
+static const H5VL_class_t null_vol_g = {
     0,                                              /* version      */
-    (H5VL_class_value_t)501,                        /* value        */
-    "echo",                                         /* name         */
+    NULL_VOL_CONNECTOR_VALUE,                       /* value        */
+    NULL_VOL_CONNECTOR_NAME,                        /* name         */
     0,                                              /* capability flags */
     NULL,                                           /* initialize   */
     NULL,                                           /* terminate    */
@@ -106,22 +107,10 @@ static const H5VL_class_t echo_vol_g = {
     NULL                                            /* optional     */
 };
 
-
-
 /* These two functions are necessary to load this plugin using
  * the HDF5 library.
  */
 
-H5PL_type_t
-H5PLget_plugin_type(void)
-{
-    return H5PL_TYPE_VOL;
-}
-
-
-const void*
-H5PLget_plugin_info(void)
-{
-    return &echo_vol_g;
-}
+H5PL_type_t H5PLget_plugin_type(void) {return H5PL_TYPE_VOL;}
+const void *H5PLget_plugin_info(void) {return &null_vol_g;}
 
diff --git a/test/null_vol_connector.h b/test/null_vol_connector.h
new file mode 100644
index 0000000..11c8826
--- /dev/null
+++ b/test/null_vol_connector.h
@@ -0,0 +1,25 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/* Purpose:     A simple virtual object layer (VOL) connector with almost no
+ *              functionality that is used for testing basic plugin handling
+ *              (registration, etc.).
+ */
+
+#ifndef _null_vol_connector_H
+#define _null_vol_connector_H
+
+#define NULL_VOL_CONNECTOR_VALUE    ((H5VL_class_value_t)160)
+#define NULL_VOL_CONNECTOR_NAME     "null_vol_connector"
+
+#endif /* _null_vol_connector_H */
+
diff --git a/test/ohdr.c b/test/ohdr.c
index cca7e7e..042a81b 100644
--- a/test/ohdr.c
+++ b/test/ohdr.c
@@ -36,9 +36,16 @@
 
 const char *FILENAME[] = {
     "ohdr",
+    "ohdr_min_a",
+    "ohdr_min_b",
     NULL
 };
 
+/* used for object header size comparison */
+#define EQ 1
+#define LT 2
+#define GT 3
+
 /* The tbogus.h5 is generated from gen_bogus.c in HDF5 'test' directory.
  * To get this data file, define H5O_ENABLE_BOGUS in src/H5Oprivate, rebuild
  * the library and simply compile gen_bogus.c with that HDF5 library and run it.
@@ -733,6 +740,885 @@ error:
     return FAIL;
 } /* test_unknown() */
 
+/*
+ * Set an attribute with the given information.
+ * If the out parameter `attr_id` is negative, a new attribute will be
+ * created with the given information. Else, it will attempt to update the
+ * attribute with the new value.
+ *
+ * `dataspace_id` ignored if `attribute_id` >= 0
+ */
+static herr_t
+put_attribute(hid_t loc_id, const char *attrname, const void *attrvalue, hid_t datatype_id, hid_t dataspace_id, hid_t *attribute_id)
+{   
+    if((*attribute_id) < 0) {
+        hid_t id = -1;
+        id = H5Acreate(loc_id, attrname, datatype_id, dataspace_id, H5P_DEFAULT, H5P_DEFAULT);
+        if(id < 0) 
+            return FAIL;
+        *attribute_id = id;
+    }
+    return H5Awrite(*attribute_id, datatype_id, attrvalue);
+} /* put_attribute */
+
+/*
+ * Count the number of attributes attached to an object.
+ * Returns negative in event of error.
+ */
+static int
+count_attributes(hid_t dset_id)
+{   
+    H5O_info_t info;
+    
+    if(H5Oget_info(dset_id, &info, H5O_INFO_ALL) < 0)
+        return -1;
+    else
+        return (int)info.num_attrs; /* should never exceed int bounds */
+} /* count_attributes */
+
+/*
+ * Get the total space used by the object header.
+ * Used by oh_compare()
+ * On success, stores size in `size_out` pointer.
+ */
+static herr_t
+_oh_getsize(hid_t did, hsize_t *size_out)
+{
+    H5O_info_t info;
+    if(FAIL == H5Oget_info2(did, &info, H5O_INFO_HDR))
+        return FAIL;
+    *size_out = info.hdr.space.total;
+    return SUCCEED;
+} /* _oh_getsize */
+
+/*
+ * Compare the TOTAL space used by datasets' object headers.
+ * Returns negative value if an error occurred,
+ * else positive #defined indicator value EQ, LT, GT.
+ */
+static int
+oh_compare(hid_t did1, hid_t did2)
+{
+    hsize_t space1 = 0;
+    hsize_t space2 = 0;
+
+    if(FAIL == _oh_getsize(did1, &space1))
+        return -1;
+    if(FAIL == _oh_getsize(did2, &space2))
+        return -2;
+
+    if(space1 < space2)
+        return LT;
+    else if(space1 > space2)
+        return GT;
+    else
+        return EQ;
+} /* oh_compare() */
+
+/*
+ * Demonstrate attribute addition to datasets.
+ * Conduct additions side-by-side with a standard datataset and one with
+ * minimized dataset object headers.
+ */
+static herr_t
+test_minimized_dset_ohdr_attribute_addition(hid_t fapl_id)
+{
+    hsize_t array_10[1]      = {10}; /* dataspace extent */
+    char    buffer[10]       = "";   /* to inspect string attribute */
+    int     a_out            = 0;
+    char    filename[512]    = "";
+    hid_t   int_type_id      = -1;
+    hid_t   char_type_id     = -1;
+    hid_t   dcpl_id          = -1;
+    hid_t   dspace_id        = -1;
+    hid_t   dspace_scalar_id = -1;
+    hid_t   dset_id          = -1;
+    hid_t   mindset_id       = -1;
+    hid_t   attr_1_id        = -1;
+    hid_t   attr_1a_id       = -1;
+    hid_t   attr_2_id        = -1;
+    hid_t   attr_2a_id       = -1;
+    hid_t   attr_3_id        = -1;
+    hid_t   attr_3a_id       = -1;
+    hid_t   file_id          = -1;
+    herr_t  ret;
+    int     count = 0;
+
+    TESTING("minimized dset object headers attribute additions")
+
+    /*********
+     * SETUP *
+     *********/
+
+    if(h5_fixname(FILENAME[1], H5P_DEFAULT, filename, sizeof(filename)) == NULL)
+        TEST_ERROR
+
+    dspace_id = H5Screate_simple(1, array_10, NULL);
+    if(dspace_id < 0) TEST_ERROR
+
+    dspace_scalar_id = H5Screate(H5S_SCALAR);
+    if(dspace_scalar_id < 0) TEST_ERROR
+
+    char_type_id = H5Tcopy(H5T_NATIVE_CHAR);
+    if(char_type_id < 0) TEST_ERROR
+
+    int_type_id = H5Tcopy(H5T_NATIVE_INT);
+    if(int_type_id < 0) TEST_ERROR
+
+    dcpl_id = H5Pcreate(H5P_DATASET_CREATE);
+    if(dcpl_id < 0) TEST_ERROR
+
+    ret = H5Pset_dset_no_attrs_hint(dcpl_id, TRUE);
+    if(ret < 0) TEST_ERROR
+
+    file_id = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl_id);
+    if(file_id < 0) TEST_ERROR
+
+    H5E_BEGIN_TRY {
+        count = count_attributes(dset_id);
+    } H5E_END_TRY;
+    if(count != -1) TEST_ERROR
+
+    dset_id = H5Dcreate(file_id, "dataset", int_type_id, dspace_id, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    if(dset_id < 0) TEST_ERROR
+
+    mindset_id  = H5Dcreate(file_id, "mindataset", int_type_id, dspace_id, H5P_DEFAULT, dcpl_id, H5P_DEFAULT);
+    if(mindset_id < 0) TEST_ERROR
+
+    /********************
+     * TEST/DEMONSTRATE *
+     ********************/
+
+    /* -------------------
+     * no attributes added
+     */
+
+    count = count_attributes(dset_id);
+    if(count != 0) TEST_ERROR
+    count = count_attributes(mindset_id);
+    if(count != 0) TEST_ERROR
+
+    /* -----------------
+     * add one attribute
+     */
+    ret = put_attribute(dset_id, "PURPOSE", "DEMO", char_type_id, dspace_id, &attr_1_id);
+    if(ret < 0) TEST_ERROR
+
+    ret = put_attribute(mindset_id, "PURPOSE", "DEMO", char_type_id, dspace_id, &attr_1a_id);
+    if(ret < 0) TEST_ERROR
+
+    count = count_attributes(dset_id);
+    if(count != 1) TEST_ERROR
+    count = count_attributes(mindset_id);
+    if(count != 1) TEST_ERROR
+
+    ret = H5Aread(attr_1_id, char_type_id, buffer);
+    if(ret < 0) TEST_ERROR
+    if(HDstrcmp("DEMO", buffer)) TEST_ERROR
+
+    ret = H5Aread(attr_1a_id, char_type_id, buffer);
+    if(ret < 0) TEST_ERROR
+    if(HDstrcmp("DEMO", buffer)) TEST_ERROR
+
+    /* -----------------
+     * modify one attribute
+     */
+
+    ret = put_attribute(dset_id, "PURPOSE", "REWRITE", char_type_id, -1, &attr_1_id);
+    if(ret < 0) TEST_ERROR
+
+    ret = put_attribute(mindset_id, "PURPOSE", "REWRITE", char_type_id, -1, &attr_1a_id);
+    if(ret < 0) TEST_ERROR
+
+    count = count_attributes(dset_id);
+    if(count != 1) TEST_ERROR
+    count = count_attributes(mindset_id);
+    if(count != 1) TEST_ERROR
+
+    ret = H5Aread(attr_1_id, char_type_id, buffer);
+    if(ret < 0) TEST_ERROR
+    if(HDstrcmp("REWRITE", buffer)) TEST_ERROR
+
+    ret = H5Aread(attr_1a_id, char_type_id, buffer);
+    if(ret < 0) TEST_ERROR
+    if(HDstrcmp("REWRITE", buffer)) TEST_ERROR
+
+    /* -----------------
+     * add second attribute
+     */
+
+    a_out = 5;
+    ret = put_attribute(dset_id, "RANK", &a_out, int_type_id, dspace_scalar_id, &attr_2_id);
+    if(ret < 0) TEST_ERROR
+
+    a_out = 3;
+    ret = put_attribute(mindset_id, "RANK", &a_out, int_type_id, dspace_scalar_id, &attr_2a_id);
+    if(ret < 0) TEST_ERROR
+
+    count = count_attributes(dset_id);
+    if(count != 2) TEST_ERROR
+    count = count_attributes(mindset_id);
+    if(count != 2) TEST_ERROR
+
+    ret = H5Aread(attr_2_id, int_type_id, &a_out);
+    if(ret < 0) TEST_ERROR
+    if(a_out != 5) TEST_ERROR
+
+    ret = H5Aread(attr_2a_id, int_type_id, &a_out);
+    if(ret < 0) TEST_ERROR
+    if(a_out != 3) TEST_ERROR
+
+    /* -----------------
+     * add third attribute
+     */
+
+    a_out = -86;
+    ret = put_attribute(dset_id, "FLAVOR", &a_out, int_type_id, dspace_scalar_id, &attr_3_id);
+    if(ret < 0) TEST_ERROR
+
+    a_out = 2185;
+    ret = put_attribute(mindset_id, "FLAVOR", &a_out, int_type_id, dspace_scalar_id, &attr_3a_id);
+    if(ret < 0) TEST_ERROR
+
+    count = count_attributes(dset_id);
+    if(count != 3) TEST_ERROR
+    count = count_attributes(mindset_id);
+    if(count != 3) TEST_ERROR
+
+    ret = H5Aread(attr_3_id, int_type_id, &a_out);
+    if(ret < 0) TEST_ERROR
+    if(a_out != -86) TEST_ERROR
+
+    ret = H5Aread(attr_3a_id, int_type_id, &a_out);
+    if(ret < 0) TEST_ERROR
+    if(a_out != 2185) TEST_ERROR
+
+    /************
+     * TEARDOWN *
+     ************/
+
+    if(H5Tclose(int_type_id) < 0) TEST_ERROR
+    if(H5Tclose(char_type_id) < 0) TEST_ERROR
+    if(H5Pclose(dcpl_id) < 0) TEST_ERROR
+    if(H5Sclose(dspace_id) < 0) TEST_ERROR
+    if(H5Dclose(dset_id) < 0) TEST_ERROR
+    if(H5Dclose(mindset_id) < 0) TEST_ERROR
+    if(H5Aclose(attr_1_id) < 0) TEST_ERROR
+    if(H5Aclose(attr_1a_id) < 0) TEST_ERROR
+    if(H5Aclose(attr_2_id) < 0) TEST_ERROR
+    if(H5Aclose(attr_2a_id) < 0) TEST_ERROR
+    if(H5Aclose(attr_3_id) < 0) TEST_ERROR
+    if(H5Aclose(attr_3a_id) < 0) TEST_ERROR
+    if(H5Fclose(file_id) < 0) TEST_ERROR
+
+    PASSED()
+    return SUCCEED;
+
+error :
+    H5E_BEGIN_TRY {
+        (void)H5Tclose(int_type_id);
+        (void)H5Tclose(char_type_id);
+        (void)H5Pclose(dcpl_id);
+        (void)H5Sclose(dspace_id);
+        (void)H5Dclose(dset_id);
+        (void)H5Dclose(mindset_id);
+        (void)H5Aclose(attr_1_id);
+        (void)H5Aclose(attr_1a_id);
+        (void)H5Aclose(attr_2_id);
+        (void)H5Aclose(attr_2a_id);
+        (void)H5Aclose(attr_3_id);
+        (void)H5Aclose(attr_3a_id);
+        (void)H5Fclose(file_id);
+    } H5E_END_TRY;
+    return FAIL;
+} /* test_minimized_dset_ohdr_attribute_addition */
+
+/*
+ * Compare header sizes against when headers have been minimized.
+ * Repeats tests with headers "compact" and normal.
+ */
+static herr_t
+test_minimized_dset_ohdr_size_comparisons(hid_t fapl_id)
+{
+    hsize_t  array_10[1] = {10}; /* dataspace extents */
+    unsigned compact     = 0;
+
+    /* IDs that are file-agnostic */
+    hid_t dspace_id     = -1;
+    hid_t int_type_id   = -1;
+    hid_t dcpl_minimize = -1;
+    hid_t dcpl_dontmin  = -1;
+    hid_t dcpl_default  = -1;
+
+    /* IDs for non-minimized file open */
+    hid_t file_f_id   = -1; /* lower 'f' for standard file setting */
+    hid_t dset_f_x_id = -1; /* 'x' for default */
+    hid_t dset_f_N_id = -1; /* 'N' for explcit non-minimized dset */
+    hid_t dset_f_Y_id = -1; /* 'Y' for minimized dset */
+
+    /* IDs for minimized file open */
+    hid_t file_F_id   = -1; /* upper 'F' for minimized file setting */
+    hid_t dset_F_x_id = -1; /* 'x' for default */
+    hid_t dset_F_N_id = -1; /* 'N' for explcit non-minimized dset */
+    hid_t dset_F_Y_id = -1; /* 'Y' for minimized dset */
+
+    char filename_a[512] = "";
+    char filename_b[512] = "";
+
+    herr_t ret;
+
+    /* dataset suffixes:
+     *                | default | minimize | don't minimize (dcpl-set)
+     * ---------------+---------+----------+---------------
+     * file-default   |   f_x   |   f_Y    |   f_N
+     * ---------------+---------+----------+---------------
+     * file-minimized |   F_x   |   F_Y    |   F_N
+     */
+
+    TESTING("minimized dset object headers size comparisons");
+
+    /*********
+     * SETUP *
+     *********/
+
+    if(h5_fixname(FILENAME[1], H5P_DEFAULT, filename_a, sizeof(filename_a)) == NULL)
+        TEST_ERROR
+
+    if(h5_fixname(FILENAME[2], H5P_DEFAULT, filename_b, sizeof(filename_b)) == NULL)
+        TEST_ERROR
+
+    for (compact = 0; compact < 2; compact++) { /* 0 or 1 */
+        dcpl_default = H5Pcreate(H5P_DATASET_CREATE);
+        if(dcpl_default < 0) TEST_ERROR
+ 
+        dcpl_minimize = H5Pcreate(H5P_DATASET_CREATE);
+        if(dcpl_minimize < 0) TEST_ERROR
+        ret = H5Pset_dset_no_attrs_hint(dcpl_minimize, TRUE);
+        if(ret < 0) TEST_ERROR
+
+        dcpl_dontmin = H5Pcreate(H5P_DATASET_CREATE);
+        if(dcpl_dontmin < 0) TEST_ERROR
+        ret = H5Pset_dset_no_attrs_hint(dcpl_dontmin, FALSE);
+        if(ret < 0) TEST_ERROR
+
+        if(compact) {
+            HDprintf("...compact ");
+            ret = H5Pset_layout(dcpl_default, H5D_COMPACT);
+            if(ret < 0) TEST_ERROR
+            ret = H5Pset_layout(dcpl_minimize, H5D_COMPACT);
+            if(ret < 0) TEST_ERROR
+            ret = H5Pset_layout(dcpl_dontmin, H5D_COMPACT);
+            if(ret < 0) TEST_ERROR
+        } else 
+            HDprintf("...not compact ");
+
+        dspace_id = H5Screate_simple(1, array_10, NULL);
+        if(dspace_id < 0) TEST_ERROR
+
+        int_type_id = H5Tcopy(H5T_NATIVE_INT);
+        if(int_type_id < 0) TEST_ERROR
+
+        file_f_id = H5Fcreate(filename_a, H5F_ACC_TRUNC, H5P_DEFAULT, fapl_id);
+        if(file_f_id < 0) TEST_ERROR
+
+        dset_f_x_id = H5Dcreate(file_f_id, "default", int_type_id, dspace_id, H5P_DEFAULT, dcpl_default, H5P_DEFAULT);
+        if(dset_f_x_id < 0) TEST_ERROR
+
+        dset_f_N_id = H5Dcreate(file_f_id, "dsetNOT", int_type_id, dspace_id, H5P_DEFAULT, dcpl_dontmin, H5P_DEFAULT);
+        if(dset_f_N_id < 0) TEST_ERROR
+
+        dset_f_Y_id = H5Dcreate(file_f_id, "dsetMIN", int_type_id, dspace_id, H5P_DEFAULT, dcpl_minimize, H5P_DEFAULT);
+        if(dset_f_x_id < 0) TEST_ERROR
+
+        file_F_id = H5Fcreate(filename_b, H5F_ACC_TRUNC, H5P_DEFAULT, fapl_id);
+        if(file_F_id < 0) TEST_ERROR
+        ret = H5Fset_dset_no_attrs_hint(file_F_id, TRUE);
+        if(ret < 0) TEST_ERROR
+
+        dset_F_x_id = H5Dcreate(file_F_id, "default", int_type_id, dspace_id, H5P_DEFAULT, dcpl_default, H5P_DEFAULT);
+        if(dset_F_x_id < 0) TEST_ERROR
+
+        dset_F_N_id = H5Dcreate(file_F_id, "dsetNOT", int_type_id, dspace_id, H5P_DEFAULT, dcpl_dontmin, H5P_DEFAULT);
+        if(dset_F_N_id < 0) TEST_ERROR
+
+        dset_F_Y_id = H5Dcreate(file_F_id, "dsetMIN", int_type_id, dspace_id, H5P_DEFAULT, dcpl_minimize, H5P_DEFAULT);
+        if(dset_F_Y_id < 0) TEST_ERROR
+
+        /*********
+         * TESTS *
+         *********/
+
+        if(oh_compare(dset_f_x_id, dset_f_x_id) != EQ) TEST_ERROR /* identity */
+
+        if(oh_compare(dset_f_x_id, dset_f_N_id) != EQ) TEST_ERROR
+        if(oh_compare(dset_f_x_id, dset_f_Y_id) != GT) TEST_ERROR
+        if(oh_compare(dset_f_N_id, dset_f_Y_id) != GT) TEST_ERROR
+
+        if(oh_compare(dset_F_x_id, dset_F_N_id) != EQ) TEST_ERROR
+        if(oh_compare(dset_F_x_id, dset_F_Y_id) != EQ) TEST_ERROR
+        if(oh_compare(dset_F_N_id, dset_F_Y_id) != EQ) TEST_ERROR
+
+        if(oh_compare(dset_F_x_id, dset_f_Y_id) != EQ) TEST_ERROR
+        if(oh_compare(dset_F_x_id, dset_f_x_id) != LT) TEST_ERROR
+
+        /************
+         * TEARDOWN *
+         ************/
+
+        if(H5Sclose(dspace_id) < 0) TEST_ERROR
+        if(H5Tclose(int_type_id) < 0) TEST_ERROR
+        if(H5Pclose(dcpl_default) < 0) TEST_ERROR
+        if(H5Pclose(dcpl_minimize) < 0) TEST_ERROR
+        if(H5Pclose(dcpl_dontmin) < 0) TEST_ERROR
+
+        if(H5Fclose(file_f_id) < 0) TEST_ERROR
+        if(H5Dclose(dset_f_x_id) < 0) TEST_ERROR
+        if(H5Dclose(dset_f_N_id) < 0) TEST_ERROR
+        if(H5Dclose(dset_f_Y_id) < 0) TEST_ERROR
+
+        if(H5Fclose(file_F_id) < 0) TEST_ERROR
+        if(H5Dclose(dset_F_x_id) < 0) TEST_ERROR
+        if(H5Dclose(dset_F_N_id) < 0) TEST_ERROR
+        if(H5Dclose(dset_F_Y_id) < 0) TEST_ERROR
+
+    } /* compact and non-compact */
+
+    PASSED()
+    return SUCCEED;
+
+error :
+    H5E_BEGIN_TRY {
+        (void)H5Pclose(dcpl_default);
+        (void)H5Pclose(dcpl_minimize);
+        (void)H5Pclose(dcpl_dontmin);
+        (void)H5Sclose(dspace_id);
+        (void)H5Tclose(int_type_id);
+
+        (void)H5Fclose(file_f_id);
+        (void)H5Dclose(dset_f_x_id);
+        (void)H5Dclose(dset_f_N_id);
+        (void)H5Dclose(dset_f_Y_id);
+
+        (void)H5Fclose(file_F_id);
+        (void)H5Dclose(dset_F_x_id);
+        (void)H5Dclose(dset_F_N_id);
+        (void)H5Dclose(dset_F_Y_id);
+    } H5E_END_TRY;
+    return FAIL;
+} /* test_minimized_dset_ohdr_size_comparisons */
+
+/*
+ * Test minimized dataset object header with filter/pipeline message
+ */
+static herr_t
+test_minimized_dset_ohdr_with_filter(hid_t fapl_id)
+{
+    char           filename[512]   = "";
+    const hsize_t  extents[1]      = {1024}; /* extents of dataspace */
+    const unsigned filter_values[] = {0};  /* TBD */
+    const hsize_t  chunk_dim[]     = {32};  /* needed for filter */
+    const int      ndims           = 1;
+    hid_t          dspace_id       = -1;
+    hid_t          dtype_id        = -1;
+    hid_t          dcpl_xZ_id      = -1;
+    hid_t          dcpl_mx_id      = -1;
+    hid_t          dcpl_mZ_id      = -1;
+    hid_t          dset_xx_id      = -1;
+    hid_t          dset_xZ_id      = -1;
+    hid_t          dset_mx_id      = -1;
+    hid_t          dset_mZ_id      = -1;
+    hid_t          file_id         = -1;
+    herr_t         ret;
+
+    /* dcpl suffixes:
+     *           | default | minimize
+     * ----------+---------+---------
+     * no filter |    xx   |   mx
+     * ----------+---------+---------
+     * filter    |    xZ   |   mZ
+     */
+
+    TESTING("minimized dset object headers with filter message");
+
+    /*********
+     * SETUP *
+     *********/
+
+    if(h5_fixname(FILENAME[1], H5P_DEFAULT, filename, sizeof(filename)) == NULL)
+        TEST_ERROR
+
+    dcpl_mx_id = H5Pcreate(H5P_DATASET_CREATE);
+    if(dcpl_mx_id < 0) TEST_ERROR
+    ret = H5Pset_dset_no_attrs_hint(dcpl_mx_id, TRUE);
+    if(ret < 0) TEST_ERROR
+
+    dcpl_xZ_id = H5Pcreate(H5P_DATASET_CREATE);
+    if(dcpl_xZ_id < 0) TEST_ERROR
+    ret = H5Pset_chunk(dcpl_xZ_id, ndims, chunk_dim);
+    if(ret < 0) TEST_ERROR
+    ret = H5Pset_filter(dcpl_xZ_id, H5Z_FILTER_DEFLATE, H5Z_FLAG_OPTIONAL, 0, filter_values);
+    if(ret < 0) TEST_ERROR
+    dcpl_mZ_id = H5Pcreate(H5P_DATASET_CREATE);
+    if(dcpl_mZ_id < 0) TEST_ERROR
+    ret = H5Pset_dset_no_attrs_hint(dcpl_mZ_id, TRUE);
+    if(ret < 0) TEST_ERROR
+    ret = H5Pset_chunk(dcpl_mZ_id, ndims, chunk_dim);
+    if(ret < 0) TEST_ERROR
+    ret = H5Pset_filter( dcpl_mZ_id, H5Z_FILTER_DEFLATE, H5Z_FLAG_OPTIONAL, 0, filter_values);
+    if(ret < 0) TEST_ERROR
+
+    dspace_id = H5Screate_simple(1, extents, extents);
+    if(dspace_id < 0) TEST_ERROR
+
+    dtype_id = H5Tcopy(H5T_NATIVE_INT);
+    if(dtype_id < 0) TEST_ERROR
+
+    file_id = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl_id);
+    if(file_id < 0) TEST_ERROR
+
+    dset_xx_id = H5Dcreate(file_id, "xx", dtype_id, dspace_id, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    if(dset_xx_id < 0) TEST_ERROR
+
+    dset_mx_id = H5Dcreate(file_id, "Mx", dtype_id, dspace_id, H5P_DEFAULT, dcpl_mx_id, H5P_DEFAULT);
+    if(dset_mx_id < 0) TEST_ERROR
+
+    dset_xZ_id = H5Dcreate(file_id, "xZ", dtype_id, dspace_id, H5P_DEFAULT, dcpl_xZ_id, H5P_DEFAULT);
+    if(dset_xZ_id < 0) TEST_ERROR
+
+    dset_mZ_id = H5Dcreate(file_id, "MZ", dtype_id, dspace_id, H5P_DEFAULT, dcpl_mZ_id, H5P_DEFAULT);
+    if(dset_mZ_id < 0) TEST_ERROR
+
+    /*********
+     * TESTS *
+     *********/
+
+    if(oh_compare(dset_mx_id, dset_xx_id) != LT) TEST_ERROR
+    if(oh_compare(dset_mx_id, dset_xZ_id) != LT) TEST_ERROR
+    if(oh_compare(dset_mZ_id, dset_mx_id) != GT) TEST_ERROR
+    if(oh_compare(dset_mZ_id, dset_xZ_id) != LT) TEST_ERROR
+
+    /************
+     * TEARDOWN *
+     ************/
+
+    if(H5Sclose(dspace_id) < 0) TEST_ERROR
+    if(H5Tclose(dtype_id) < 0) TEST_ERROR
+    if(H5Pclose(dcpl_xZ_id) < 0) TEST_ERROR
+    if(H5Pclose(dcpl_mx_id) < 0) TEST_ERROR
+    if(H5Pclose(dcpl_mZ_id) < 0) TEST_ERROR
+    if(H5Dclose(dset_xx_id) < 0) TEST_ERROR
+    if(H5Dclose(dset_xZ_id) < 0) TEST_ERROR
+    if(H5Dclose(dset_mx_id) < 0) TEST_ERROR
+    if(H5Dclose(dset_mZ_id) < 0) TEST_ERROR
+    if(H5Fclose(file_id) < 0) TEST_ERROR
+
+    PASSED()
+    return SUCCEED;
+
+error:
+    H5E_BEGIN_TRY {
+        (void)H5Sclose(dspace_id);
+        (void)H5Tclose(dtype_id);
+        (void)H5Pclose(dcpl_xZ_id);
+        (void)H5Pclose(dcpl_mx_id);
+        (void)H5Pclose(dcpl_mZ_id);
+        (void)H5Dclose(dset_xx_id);
+        (void)H5Dclose(dset_xZ_id);
+        (void)H5Dclose(dset_mx_id);
+        (void)H5Dclose(dset_mZ_id);
+        (void)H5Fclose(file_id);
+    } H5E_END_TRY;
+    return FAIL;
+} /* test_minimized_dset_ohdr_with_filter */
+
+/*
+ * Test minimized dataset object header and recording modification times.
+ */
+static herr_t
+test_minimized_dset_ohdr_modification_times(hid_t _fapl_id)
+{
+    /* test-local structure for parameterized testing
+     */
+    struct testcase {
+        unsigned oh_version;
+    };
+
+    char          filename[512] = "";
+    const hsize_t extents[1]    = {128}; /* extents of dataspace */
+    hid_t         dspace_id     = -1;
+    hid_t         dtype_id      = -1;
+    hid_t         dcpl_xT_id    = -1; /* Track modtime */
+    hid_t         dcpl_mx_id    = -1; /* minimized */
+    hid_t         dcpl_mT_id    = -1; /* minimized, Track */
+    hid_t         dcpl_mN_id    = -1; /* minimized, do Not track */
+    hid_t         dset_xx_id    = -1;
+    hid_t         dset_xT_id    = -1;
+    hid_t         dset_mx_id    = -1;
+    hid_t         dset_mT_id    = -1;
+    hid_t         dset_mN_id    = -1;
+    hid_t         file_id       = -1;
+    hid_t         fapl_id       = -1;
+    herr_t        ret;
+
+    unsigned i       = 0; /* for testcase loop */
+    unsigned n_cases = 2; /* must match `cases` array size below */
+    struct testcase cases[2] = {
+        { 1, }, /* version 1 object header */
+        { 2, }, /* version 2 object header */
+    };
+
+    /* dcpl suffixes:
+     *             | default | minimize
+     * ------------+---------+---------
+     * default     |    xx   |   mx
+     * ------------+---------+---------
+     * don't track |    xN   |   mN
+     * ------------+---------+---------
+     * track       |    xT   |   mT
+     */
+
+    TESTING("minimized dset object headers with modification times");
+
+    /*********
+     * SETUP *
+     *********/
+
+    if(h5_fixname(FILENAME[1], H5P_DEFAULT, filename, sizeof(filename)) == NULL)
+        TEST_ERROR
+
+    dcpl_mx_id = H5Pcreate(H5P_DATASET_CREATE);
+    if(dcpl_mx_id < 0) TEST_ERROR
+    ret = H5Pset_dset_no_attrs_hint(dcpl_mx_id, TRUE);
+    if(ret < 0) TEST_ERROR
+
+    dcpl_xT_id = H5Pcreate(H5P_DATASET_CREATE);
+    if(dcpl_xT_id < 0) TEST_ERROR
+    ret = H5Pset_obj_track_times(dcpl_xT_id, TRUE);
+    if(ret < 0) TEST_ERROR
+
+    dcpl_mT_id = H5Pcreate(H5P_DATASET_CREATE);
+    if(dcpl_mT_id < 0) TEST_ERROR
+    ret = H5Pset_dset_no_attrs_hint(dcpl_mT_id, TRUE);
+    if(ret < 0) TEST_ERROR
+    ret = H5Pset_obj_track_times(dcpl_mT_id, TRUE);
+    if(ret < 0) TEST_ERROR
+
+    dcpl_mN_id = H5Pcreate(H5P_DATASET_CREATE);
+    if(dcpl_mN_id < 0) TEST_ERROR
+    ret = H5Pset_dset_no_attrs_hint(dcpl_mN_id, TRUE);
+    if(ret < 0) TEST_ERROR
+    ret = H5Pset_obj_track_times(dcpl_mN_id, FALSE);
+    if(ret < 0) TEST_ERROR
+
+    dspace_id = H5Screate_simple(1, extents, extents);
+    if(dspace_id < 0) TEST_ERROR
+
+    dtype_id = H5Tcopy(H5T_NATIVE_INT);
+    if(dtype_id < 0) TEST_ERROR
+
+    for (i = 0; i < n_cases; i++) {
+
+        /* -------------- *
+         * per-case setup *
+         * -------------- */
+
+        fapl_id = H5Pcopy(_fapl_id);
+        if(fapl_id < 0) TEST_ERROR
+
+        if(cases[i].oh_version > 1) {
+            fapl_id = H5Pcreate(H5P_FILE_ACCESS);
+            if(fapl_id < 0) TEST_ERROR
+            ret = H5Pset_libver_bounds(fapl_id, H5F_LIBVER_V18, H5F_LIBVER_V110);
+            if(ret < 0) TEST_ERROR
+        }
+
+        file_id = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl_id);
+        if(file_id < 0) TEST_ERROR
+
+        dset_xx_id = H5Dcreate( file_id, "xx", dtype_id, dspace_id, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+        if(dset_xx_id < 0) TEST_ERROR
+
+        dset_mx_id = H5Dcreate(file_id, "mx", dtype_id, dspace_id, H5P_DEFAULT, dcpl_mx_id, H5P_DEFAULT);
+        if(dset_mx_id < 0) TEST_ERROR
+
+        dset_xT_id = H5Dcreate(file_id, "xT", dtype_id, dspace_id, H5P_DEFAULT, dcpl_xT_id, H5P_DEFAULT);
+        if(dset_xT_id < 0) TEST_ERROR
+        dset_mT_id = H5Dcreate(file_id, "mT", dtype_id, dspace_id, H5P_DEFAULT, dcpl_mT_id, H5P_DEFAULT);
+        if(dset_mT_id < 0) TEST_ERROR
+
+        dset_mN_id = H5Dcreate(file_id, "mN", dtype_id, dspace_id, H5P_DEFAULT, dcpl_mN_id, H5P_DEFAULT);
+        if(dset_mN_id < 0) TEST_ERROR
+
+        /* ----- *
+         * TESTS *
+         * ----- */
+
+        /* sanity check */
+        if(oh_compare(dset_mx_id, dset_xx_id) != LT) TEST_ERROR
+        if(oh_compare(dset_mx_id, dset_xT_id) != LT) TEST_ERROR
+
+        if(oh_compare(dset_xx_id, dset_xT_id) != EQ) TEST_ERROR
+        if(oh_compare(dset_mx_id, dset_mT_id) != EQ) TEST_ERROR
+        if(oh_compare(dset_mN_id, dset_mT_id) != LT) TEST_ERROR
+
+        if(oh_compare(dset_mT_id, dset_xT_id) != LT) TEST_ERROR
+
+        /* ----------------- *
+         * per-case teardown *
+         * ----------------- */
+
+        if(H5Dclose(dset_xx_id) < 0) TEST_ERROR
+        if(H5Dclose(dset_xT_id) < 0) TEST_ERROR
+        if(H5Dclose(dset_mx_id) < 0) TEST_ERROR
+        if(H5Dclose(dset_mT_id) < 0) TEST_ERROR
+        if(H5Dclose(dset_mN_id) < 0) TEST_ERROR
+        if(H5Fclose(file_id) < 0) TEST_ERROR
+        if(H5Pclose(fapl_id) < 0) TEST_ERROR
+
+    } /* for each version tested */
+
+    /************
+     * TEARDOWN *
+     ************/
+
+    if(H5Sclose(dspace_id) < 0) TEST_ERROR
+    if(H5Tclose(dtype_id) < 0) TEST_ERROR
+    if(H5Pclose(dcpl_xT_id) < 0) TEST_ERROR
+    if(H5Pclose(dcpl_mx_id) < 0) TEST_ERROR
+    if(H5Pclose(dcpl_mT_id) < 0) TEST_ERROR
+    if(H5Pclose(dcpl_mN_id) < 0) TEST_ERROR
+
+    PASSED()
+    return SUCCEED;
+
+error:
+    H5E_BEGIN_TRY {
+        (void)H5Sclose(dspace_id);
+        (void)H5Tclose(dtype_id);
+        (void)H5Pclose(dcpl_xT_id);
+        (void)H5Pclose(dcpl_mx_id);
+        (void)H5Pclose(dcpl_mT_id);
+        (void)H5Pclose(dcpl_mN_id);
+        (void)H5Dclose(dset_xx_id);
+        (void)H5Dclose(dset_xT_id);
+        (void)H5Dclose(dset_mx_id);
+        (void)H5Dclose(dset_mT_id);
+        (void)H5Dclose(dset_mN_id);
+        (void)H5Fclose(file_id);
+        (void)H5Pclose(fapl_id);
+    } H5E_END_TRY;
+    return FAIL;
+} /* test_minimized_dset_ohdr_modification_times */
+
+/*
+ * Test minimized dataset object header with a fill value set.
+ */
+static herr_t
+test_minimized_dset_ohdr_fillvalue_backwards_compatability(hid_t _fapl_id)
+{
+    char          filename[512] = "";
+    const hsize_t extents[1]    = {64}; /* extents of dataspace */
+    const int     fill[1]       = {343}; /* fill value of dataset */
+    hid_t         file_id       = -1;
+    hid_t         dtype_id      = -1;
+    hid_t         dspace_id     = -1;
+    hid_t         dcpl_id       = -1;
+    hid_t         fapl_id       = -1;
+    hid_t         dset_0_id     = -1;
+    hid_t         dset_1_id     = -1;
+    herr_t        ret;
+
+    /*********
+     * SETUP *
+     *********/
+
+    TESTING("minimized dset object headers with fill values and different libver support");
+
+    if(h5_fixname(FILENAME[1], H5P_DEFAULT, filename, sizeof(filename)) == NULL)
+        TEST_ERROR
+
+    dspace_id = H5Screate_simple(1, extents, extents);
+    if(dspace_id < 0) TEST_ERROR
+
+    dtype_id = H5Tcopy(H5T_NATIVE_INT);
+    if(dtype_id < 0) TEST_ERROR
+
+    dcpl_id = H5Pcreate(H5P_DATASET_CREATE);
+    if(dcpl_id < 0) TEST_ERROR
+
+    ret = H5Pset_dset_no_attrs_hint(dcpl_id, TRUE);
+    if(ret == FAIL) TEST_ERROR;
+
+    ret = H5Pset_fill_value(dcpl_id, dtype_id, fill);
+    if(ret == FAIL) TEST_ERROR;
+
+    fapl_id = H5Pcopy(_fapl_id);
+    if(fapl_id < 0) TEST_ERROR
+
+    ret = H5Pset_libver_bounds(fapl_id, H5F_LIBVER_EARLIEST, H5F_LIBVER_LATEST);
+    if(ret == FAIL) TEST_ERROR;
+
+    file_id = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl_id);
+    if(file_id < 0) TEST_ERROR
+
+    dset_0_id = H5Dcreate(file_id, "fullrange", dtype_id, dspace_id, H5P_DEFAULT, dcpl_id, H5P_DEFAULT);
+    if(dset_0_id < 0) TEST_ERROR
+
+    /* Close file and re-open with different libver bounds.
+     * Dataset "fullrange" must also be closed for expected reopen behavior.
+     */
+    if(H5Fclose(file_id) < 0) TEST_ERROR;
+    if(H5Dclose(dset_0_id) < 0) TEST_ERROR
+
+    ret = H5Pset_libver_bounds(fapl_id, H5F_LIBVER_V18, H5F_LIBVER_LATEST);
+    if(ret == FAIL) TEST_ERROR;
+
+    file_id = H5Fopen(filename, H5F_ACC_RDWR, fapl_id);
+    if(file_id < 0) TEST_ERROR
+
+    dset_1_id = H5Dcreate(file_id, "upperrange", dtype_id, dspace_id, H5P_DEFAULT, dcpl_id, H5P_DEFAULT);
+    if(dset_1_id < 0) TEST_ERROR
+
+    /* re-open "fullrange" dataset
+     */
+     dset_0_id = H5Dopen2(file_id, "fullrange", H5P_DEFAULT);
+     if(dset_0_id < 0) TEST_ERROR
+
+    /*********
+     * TESTS *
+     *********/
+
+    /* dset not supporting pre-1.08 should be smaller? */
+    if(oh_compare(dset_1_id, dset_0_id) != LT) TEST_ERROR
+
+    /************
+     * TEARDOWN *
+     ************/
+
+    if(H5Sclose(dspace_id) < 0) TEST_ERROR
+    if(H5Tclose(dtype_id) < 0) TEST_ERROR
+    if(H5Pclose(dcpl_id) < 0) TEST_ERROR
+    if(H5Pclose(fapl_id) < 0) TEST_ERROR
+    if(H5Dclose(dset_0_id) < 0) TEST_ERROR
+    if(H5Dclose(dset_1_id) < 0) TEST_ERROR
+    if(H5Fclose(file_id) < 0) TEST_ERROR;
+
+    PASSED()
+    return SUCCEED;
+
+error:
+    H5E_BEGIN_TRY {
+        (void)H5Sclose(dspace_id);
+        (void)H5Tclose(dtype_id);
+        (void)H5Pclose(dcpl_id);
+        (void)H5Pclose(fapl_id);
+        (void)H5Dclose(dset_0_id);
+        (void)H5Dclose(dset_1_id);
+        (void)H5Fclose(file_id);
+    } H5E_END_TRY;
+    return FAIL;
+} /* test_minimized_dset_ohdr_fillvalue_backwards_compatability */
+
 #define STR_EARLIEST "earliest"
 #define STR_V18 "v18"
 #define STR_LATEST "latest"
@@ -1030,6 +1916,21 @@ main(void)
         if(test_ohdr_cache(filename, fapl) < 0)
             TEST_ERROR
 
+        if(test_minimized_dset_ohdr_attribute_addition(fapl) < 0)
+            TEST_ERROR
+
+        if(test_minimized_dset_ohdr_size_comparisons(fapl) < 0)
+            TEST_ERROR
+
+        if(test_minimized_dset_ohdr_with_filter(fapl) < 0)
+            TEST_ERROR
+
+        if(test_minimized_dset_ohdr_modification_times(fapl) < 0)
+            TEST_ERROR
+
+        if(test_minimized_dset_ohdr_fillvalue_backwards_compatability(fapl) < 0)
+            TEST_ERROR
+
       } /* high */
     } /* low */
 
diff --git a/test/tattr.c b/test/tattr.c
index 63a0580..c1167c6 100644
--- a/test/tattr.c
+++ b/test/tattr.c
@@ -146,6 +146,10 @@ float attr_data5=-5.123F;        /* Test data for 5th attribute */
 /* Used by test_attr_info_null_info_pointer() */
 #define GET_INFO_NULL_POINTER_ATTR_NAME "NullInfoPointerAttr"
 
+/* Used by test_attr_rename_invalid_name() */
+#define INVALID_RENAME_TEST_ATTR_NAME "InvalidRenameTestAttr"
+#define INVALID_RENAME_TEST_NEW_ATTR_NAME "InvalidRenameTestNewAttr"
+
 
 /* Attribute iteration struct */
 typedef struct {
@@ -161,6 +165,12 @@ typedef struct {
 static herr_t attr_op1(hid_t loc_id, const char *name, const H5A_info_t *ainfo,
     void *op_data);
 
+/* Global dcpl ID, can be re-set as a generated dcpl for various operations
+ * across multiple tests.
+ * e.g., minimized dataset object headers
+ */
+static hid_t dcpl_g = H5P_DEFAULT;
+
 
 
 /****************************************************************
@@ -200,7 +210,7 @@ test_attr_basic_write(hid_t fapl)
     CHECK(sid1, FAIL, "H5Screate_simple");
 
     /* Create a dataset */
-    dataset = H5Dcreate2(fid1, DSET1_NAME, H5T_NATIVE_UCHAR, sid1, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    dataset = H5Dcreate2(fid1, DSET1_NAME, H5T_NATIVE_UCHAR, sid1, H5P_DEFAULT, dcpl_g, H5P_DEFAULT);
     CHECK(dataset, FAIL, "H5Dcreate2");
 
     /* Create dataspace for attribute */
@@ -520,7 +530,7 @@ test_attr_flush(hid_t fapl)
     spc = H5Screate(H5S_SCALAR);
     CHECK(spc, FAIL, "H5Screate");
 
-    set = H5Dcreate2(fil, DSET1_NAME, H5T_NATIVE_DOUBLE, spc, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    set = H5Dcreate2(fil, DSET1_NAME, H5T_NATIVE_DOUBLE, spc, H5P_DEFAULT, dcpl_g, H5P_DEFAULT);
     CHECK(set, FAIL, "H5Dcreate2");
 
     att = H5Acreate2(set, ATTR1_NAME, H5T_NATIVE_DOUBLE, spc, H5P_DEFAULT, H5P_DEFAULT);
@@ -591,7 +601,7 @@ test_attr_plist(hid_t fapl)
     CHECK(sid1, FAIL, "H5Screate_simple");
 
     /* Create a dataset */
-    dataset = H5Dcreate2(fid1, DSET1_NAME, H5T_NATIVE_UCHAR, sid1, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    dataset = H5Dcreate2(fid1, DSET1_NAME, H5T_NATIVE_UCHAR, sid1, H5P_DEFAULT, dcpl_g, H5P_DEFAULT);
     CHECK(dataset, FAIL, "H5Dcreate2");
 
     /* Create dataspace for attribute */
@@ -705,7 +715,7 @@ test_attr_compound_write(hid_t fapl)
     CHECK(sid1, FAIL, "H5Screate_simple");
 
     /* Create a dataset */
-    dataset = H5Dcreate2(fid1, DSET1_NAME, H5T_NATIVE_UCHAR, sid1, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    dataset = H5Dcreate2(fid1, DSET1_NAME, H5T_NATIVE_UCHAR, sid1, H5P_DEFAULT, dcpl_g, H5P_DEFAULT);
     CHECK(dataset, FAIL, "H5Dcreate2");
 
     /* Close dataset's dataspace */
@@ -941,7 +951,7 @@ test_attr_scalar_write(hid_t fapl)
     CHECK(sid1, FAIL, "H5Screate_simple");
 
     /* Create a dataset */
-    dataset = H5Dcreate2(fid1, DSET1_NAME, H5T_NATIVE_UCHAR, sid1, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    dataset = H5Dcreate2(fid1, DSET1_NAME, H5T_NATIVE_UCHAR, sid1, H5P_DEFAULT, dcpl_g, H5P_DEFAULT);
     CHECK(dataset, FAIL, "H5Dcreate2");
 
     /* Create dataspace for attribute */
@@ -1082,7 +1092,7 @@ test_attr_mult_write(hid_t fapl)
     CHECK(sid1, FAIL, "H5Screate_simple");
 
     /* Create a dataset */
-    dataset = H5Dcreate2(fid1, DSET1_NAME, H5T_NATIVE_UCHAR, sid1, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    dataset = H5Dcreate2(fid1, DSET1_NAME, H5T_NATIVE_UCHAR, sid1, H5P_DEFAULT, dcpl_g, H5P_DEFAULT);
     CHECK(dataset, FAIL, "H5Dcreate2");
 
     /* Close dataset's dataspace */
@@ -1460,7 +1470,7 @@ test_attr_iterate(hid_t fapl)
     CHECK(sid, FAIL, "H5Screate");
 
     /* Create a new dataset */
-    dataset = H5Dcreate2(file, DSET2_NAME, H5T_NATIVE_INT, sid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    dataset = H5Dcreate2(file, DSET2_NAME, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl_g, H5P_DEFAULT);
     CHECK(dataset, FAIL, "H5Dcreate2");
 
     /* Close dataspace */
@@ -1684,7 +1694,7 @@ test_attr_dtype_shared(hid_t fapl)
     CHECK(space_id, FAIL, "H5Screate");
 
     /* Create dataset */
-    dset_id = H5Dcreate2(file_id, DSET1_NAME, type_id, space_id, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    dset_id = H5Dcreate2(file_id, DSET1_NAME, type_id, space_id, H5P_DEFAULT, dcpl_g, H5P_DEFAULT);
     CHECK(dset_id, FAIL, "H5Dcreate2");
 
     /* Check reference count on named datatype */
@@ -1838,7 +1848,7 @@ test_attr_duplicate_ids(hid_t fapl)
 
     /* Create a dataset */
     dataset = H5Dcreate2(fid1, DSET1_NAME, H5T_NATIVE_UCHAR, sid1, H5P_DEFAULT,
-            H5P_DEFAULT, H5P_DEFAULT);
+            dcpl_g, H5P_DEFAULT);
     CHECK(dataset, FAIL, "H5Dcreate2");
 
     /* Create dataspace for attribute */
@@ -2163,9 +2173,14 @@ test_attr_dense_create(hid_t fcpl, hid_t fapl)
     sid = H5Screate(H5S_SCALAR);
     CHECK(sid, FAIL, "H5Screate");
 
-    /* Query the group creation properties */
-    dcpl = H5Pcreate(H5P_DATASET_CREATE);
-    CHECK(dcpl, FAIL, "H5Pcreate");
+    /* need DCPL to query the group creation properties */
+    if (dcpl_g == H5P_DEFAULT) {
+        dcpl = H5Pcreate(H5P_DATASET_CREATE);
+        CHECK(dcpl, FAIL, "H5Pcreate");
+    } else {
+        dcpl = H5Pcopy(dcpl_g);
+        CHECK(dcpl, FAIL, "H5Pcopy");
+    }
 
     /* Create a dataset */
     dataset = H5Dcreate2(fid, DSET1_NAME, H5T_NATIVE_UCHAR, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT);
@@ -2294,9 +2309,14 @@ test_attr_dense_open(hid_t fcpl, hid_t fapl)
     sid = H5Screate(H5S_SCALAR);
     CHECK(sid, FAIL, "H5Screate");
 
-    /* Query the group creation properties */
-    dcpl = H5Pcreate(H5P_DATASET_CREATE);
-    CHECK(dcpl, FAIL, "H5Pcreate");
+    /* need DCPL to query the group creation properties */
+    if (dcpl_g == H5P_DEFAULT) {
+        dcpl = H5Pcreate(H5P_DATASET_CREATE);
+        CHECK(dcpl, FAIL, "H5Pcreate");
+    } else {
+        dcpl = H5Pcopy(dcpl_g);
+        CHECK(dcpl, FAIL, "H5Pcopy");
+    }
 
     /* Enable creation order tracking on attributes, so creation order tests work */
     ret = H5Pset_attr_creation_order(dcpl, H5P_CRT_ORDER_TRACKED);
@@ -2408,14 +2428,25 @@ test_attr_dense_delete(hid_t fcpl, hid_t fapl)
     h5_stat_size_t empty_filesize;       /* Size of empty file */
     h5_stat_size_t filesize;             /* Size of file after modifications */
     H5O_info_t  oinfo;          /* Object info                  */
+    int         use_min_dset_oh = (dcpl_g != H5P_DEFAULT);
     herr_t      ret;            /* Generic return value        */
 
     /* Output message about test being performed */
     MESSAGE(5, ("Testing Deleting Attributes in Dense Storage\n"));
 
-    /* Create file */
+    if (use_min_dset_oh) { /* using minimized dataset headers */
+        /* modify fcpl...
+         * sidestep "bug" where file space is lost with minimized dset ohdrs
+         */
+        fcpl = H5Pcopy(fcpl);
+        CHECK(fcpl, FAIL, "H5Pcopy");
+        ret = H5Pset_file_space_strategy(fcpl, H5F_FSPACE_STRATEGY_FSM_AGGR, TRUE, 1);
+        CHECK(ret, FAIL, "H5Pset_file_space_strategy");
+    }
     fid = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl, fapl);
     CHECK(fid, FAIL, "H5Fcreate");
+    if (use_min_dset_oh)
+        CHECK(H5Pclose(fcpl), FAIL, "H5Pclose");
 
     /* Close file */
     ret = H5Fclose(fid);
@@ -2434,9 +2465,14 @@ test_attr_dense_delete(hid_t fcpl, hid_t fapl)
     sid = H5Screate(H5S_SCALAR);
     CHECK(sid, FAIL, "H5Screate");
 
-    /* Query the group creation properties */
-    dcpl = H5Pcreate(H5P_DATASET_CREATE);
-    CHECK(dcpl, FAIL, "H5Pcreate");
+    /* need DCPL to query the group creation properties */
+    if (use_min_dset_oh) {
+        dcpl = H5Pcopy(dcpl_g);
+        CHECK(dcpl, FAIL, "H5Pcopy");
+    } else {
+        dcpl = H5Pcreate(H5P_DATASET_CREATE);
+        CHECK(dcpl, FAIL, "H5Pcreate");
+    }
 
     /* Enable creation order tracking on attributes, so creation order tests work */
     ret = H5Pset_attr_creation_order(dcpl, H5P_CRT_ORDER_TRACKED);
@@ -2587,14 +2623,25 @@ test_attr_dense_rename(hid_t fcpl, hid_t fapl)
     h5_stat_size_t filesize;             /* Size of file after modifications */
     H5O_info_t  oinfo;          /* Object info */
     unsigned    u;              /* Local index variable */
+    int         use_min_dset_oh = (dcpl_g != H5P_DEFAULT);
     herr_t      ret;            /* Generic return value        */
 
     /* Output message about test being performed */
     MESSAGE(5, ("Testing Renaming Attributes in Dense Storage\n"));
 
-    /* Create file */
+    if (use_min_dset_oh) { /* using minimized dataset headers */
+        /* modify fcpl...
+         * sidestep "bug" where file space is lost with minimized dset ohdrs
+         */
+        fcpl = H5Pcopy(fcpl);
+        CHECK(fcpl, FAIL, "H5Pcopy");
+        ret = H5Pset_file_space_strategy(fcpl, H5F_FSPACE_STRATEGY_FSM_AGGR, TRUE, 1);
+        CHECK(ret, FAIL, "H5Pset_file_space_strategy");
+    }
     fid = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl, fapl);
     CHECK(fid, FAIL, "H5Fcreate");
+    if (use_min_dset_oh)
+        CHECK(H5Pclose(fcpl), FAIL, "H5Pclose");
 
     /* Close file */
     ret = H5Fclose(fid);
@@ -2613,9 +2660,14 @@ test_attr_dense_rename(hid_t fcpl, hid_t fapl)
     sid = H5Screate(H5S_SCALAR);
     CHECK(sid, FAIL, "H5Screate");
 
-    /* Query the group creation properties */
-    dcpl = H5Pcreate(H5P_DATASET_CREATE);
-    CHECK(dcpl, FAIL, "H5Pcreate");
+    /* need DCPL to query the group creation properties */
+    if (use_min_dset_oh) {
+        dcpl = H5Pcopy(dcpl_g);
+        CHECK(dcpl, FAIL, "H5Pcopy");
+    } else {
+        dcpl = H5Pcreate(H5P_DATASET_CREATE);
+        CHECK(dcpl, FAIL, "H5Pcreate");
+    }
 
     /* Create a dataset */
     dataset = H5Dcreate2(fid, DSET1_NAME, H5T_NATIVE_UCHAR, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT);
@@ -2746,20 +2798,29 @@ test_attr_dense_unlink(hid_t fcpl, hid_t fapl)
     h5_stat_size_t filesize;             /* Size of file after modifications */
     H5O_info_t  oinfo;          /* Object info */
     unsigned    u;              /* Local index variable */
+    int         use_min_dset_oh = (dcpl_g != H5P_DEFAULT);
     herr_t      ret;            /* Generic return value        */
 
     /* Output message about test being performed */
     MESSAGE(5, ("Testing Unlinking Object with Attributes in Dense Storage\n"));
 
-    /* Create file */
+    if (use_min_dset_oh) { /* using minimized dataset headers */
+        /* modify fcpl...
+         * sidestep "bug" where file space is lost with minimized dset ohdrs
+         */
+        fcpl = H5Pcopy(fcpl);
+        CHECK(fcpl, FAIL, "H5Pcopy");
+        ret = H5Pset_file_space_strategy(fcpl, H5F_FSPACE_STRATEGY_FSM_AGGR, TRUE, 1);
+        CHECK(ret, FAIL, "H5Pset_file_space_strategy");
+    }
     fid = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl, fapl);
     CHECK(fid, FAIL, "H5Fcreate");
+    if (use_min_dset_oh)
+        CHECK(H5Pclose(fcpl), FAIL, "H5Pclose");
 
-    /* Close file */
     ret = H5Fclose(fid);
     CHECK(ret, FAIL, "H5Fclose");
 
-    /* Get size of file */
     empty_filesize = h5_get_file_size(FILENAME, fapl);
     if(empty_filesize < 0)
         TestErrPrintf("Line %d: file size wrong!\n", __LINE__);
@@ -2772,9 +2833,14 @@ test_attr_dense_unlink(hid_t fcpl, hid_t fapl)
     sid = H5Screate(H5S_SCALAR);
     CHECK(sid, FAIL, "H5Screate");
 
-    /* Query the group creation properties */
-    dcpl = H5Pcreate(H5P_DATASET_CREATE);
-    CHECK(dcpl, FAIL, "H5Pcreate");
+    /* need DCPL to query the group creation properties */
+    if (use_min_dset_oh) {
+        dcpl = H5Pcopy(dcpl_g);
+        CHECK(dcpl, FAIL, "H5Pcopy");
+    } else {
+        dcpl = H5Pcreate(H5P_DATASET_CREATE);
+        CHECK(dcpl, FAIL, "H5Pcreate");
+    }
 
     /* Create a dataset */
     dataset = H5Dcreate2(fid, DSET1_NAME, H5T_NATIVE_UCHAR, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT);
@@ -2900,9 +2966,14 @@ test_attr_dense_limits(hid_t fcpl, hid_t fapl)
     sid = H5Screate(H5S_SCALAR);
     CHECK(sid, FAIL, "H5Screate");
 
-    /* Query the group creation properties */
-    dcpl = H5Pcreate(H5P_DATASET_CREATE);
-    CHECK(dcpl, FAIL, "H5Pcreate");
+    /* need DCPL to query the group creation properties */
+    if (dcpl_g == H5P_DEFAULT) {
+        dcpl = H5Pcreate(H5P_DATASET_CREATE);
+        CHECK(dcpl, FAIL, "H5Pcreate");
+    } else {
+        dcpl = H5Pcopy(dcpl_g);
+        CHECK(dcpl, FAIL, "H5Pcopy");
+    }
 
     /* Change limits on compact/dense attribute storage */
     max_compact = 0;
@@ -3067,9 +3138,14 @@ test_attr_dense_dup_ids(hid_t fcpl, hid_t fapl)
     sid = H5Screate(H5S_SCALAR);
     CHECK(sid, FAIL, "H5Screate");
 
-    /* Query the group creation properties */
-    dcpl = H5Pcreate(H5P_DATASET_CREATE);
-    CHECK(dcpl, FAIL, "H5Pcreate");
+    /* need DCPL to query the group creation properties */
+    if (dcpl_g == H5P_DEFAULT) {
+        dcpl = H5Pcreate(H5P_DATASET_CREATE);
+        CHECK(dcpl, FAIL, "H5Pcreate");
+    } else {
+        dcpl = H5Pcopy(dcpl_g);
+        CHECK(dcpl, FAIL, "H5Pcopy");
+    }
 
     /* Create a dataset */
     dataset = H5Dcreate2(fid, DSET1_NAME, H5T_NATIVE_UCHAR, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT);
@@ -3597,9 +3673,14 @@ test_attr_big(hid_t fcpl, hid_t fapl)
     big_sid = H5Screate_simple(ATTR6_RANK, dims, NULL);
     CHECK(big_sid, FAIL, "H5Screate_simple");
 
-    /* Query the group creation properties */
-    dcpl = H5Pcreate(H5P_DATASET_CREATE);
-    CHECK(dcpl, FAIL, "H5Pcreate");
+    /* need DCPL to query the group creation properties */
+    if (dcpl_g == H5P_DEFAULT) {
+        dcpl = H5Pcreate(H5P_DATASET_CREATE);
+        CHECK(dcpl, FAIL, "H5Pcreate");
+    } else {
+        dcpl = H5Pcopy(dcpl_g);
+        CHECK(dcpl, FAIL, "H5Pcopy");
+    }
 
     /* Retrieve limits for compact/dense attribute storage */
     ret = H5Pget_attr_phase_change(dcpl, &max_compact, &min_dense);
@@ -3864,7 +3945,7 @@ test_attr_null_space(hid_t fcpl, hid_t fapl)
     CHECK(null_sid, FAIL, "H5Screate");
 
     /* Create a dataset */
-    dataset = H5Dcreate2(fid, DSET1_NAME, H5T_NATIVE_UCHAR, sid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    dataset = H5Dcreate2(fid, DSET1_NAME, H5T_NATIVE_UCHAR, sid, H5P_DEFAULT, dcpl_g, H5P_DEFAULT);
     CHECK(dataset, FAIL, "H5Dcreate2");
 
 
@@ -4057,7 +4138,7 @@ test_attr_deprec(hid_t fcpl, hid_t fapl)
     CHECK(sid, FAIL, "H5Screate");
 
     /* Create a dataset */
-    dataset = H5Dcreate2(fid, DSET1_NAME, H5T_NATIVE_UCHAR, sid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    dataset = H5Dcreate2(fid, DSET1_NAME, H5T_NATIVE_UCHAR, sid, H5P_DEFAULT, dcpl_g, H5P_DEFAULT);
     CHECK(dataset, FAIL, "H5Dcreate2");
 
 
@@ -4292,8 +4373,13 @@ test_attr_corder_create_basic(hid_t fcpl, hid_t fapl)
     CHECK(fid, FAIL, "H5Fcreate");
 
     /* Create dataset creation property list */
-    dcpl = H5Pcreate(H5P_DATASET_CREATE);
-    CHECK(dcpl, FAIL, "H5Pcreate");
+    if (dcpl_g == H5P_DEFAULT) {
+        dcpl = H5Pcreate(H5P_DATASET_CREATE);
+        CHECK(dcpl, FAIL, "H5Pcreate");
+    } else {
+        dcpl = H5Pcopy(dcpl_g);
+        CHECK(dcpl, FAIL, "H5Pcopy");
+    }
 
     /* Get creation order indexing on object */
     ret = H5Pget_attr_creation_order(dcpl, &crt_order_flags);
@@ -4415,8 +4501,13 @@ test_attr_corder_create_compact(hid_t fcpl, hid_t fapl)
     CHECK(fid, FAIL, "H5Fcreate");
 
     /* Create dataset creation property list */
-    dcpl = H5Pcreate(H5P_DATASET_CREATE);
-    CHECK(dcpl, FAIL, "H5Pcreate");
+    if (dcpl_g == H5P_DEFAULT) {
+        dcpl = H5Pcreate(H5P_DATASET_CREATE);
+        CHECK(dcpl, FAIL, "H5Pcreate");
+    } else {
+        dcpl = H5Pcopy(dcpl_g);
+        CHECK(dcpl, FAIL, "H5Pcopy");
+    }
 
     /* Set attribute creation order tracking & indexing for object */
     ret = H5Pset_attr_creation_order(dcpl, (H5P_CRT_ORDER_TRACKED | H5P_CRT_ORDER_INDEXED));
@@ -4615,8 +4706,13 @@ test_attr_corder_create_dense(hid_t fcpl, hid_t fapl)
     CHECK(fid, FAIL, "H5Fcreate");
 
     /* Create dataset creation property list */
-    dcpl = H5Pcreate(H5P_DATASET_CREATE);
-    CHECK(dcpl, FAIL, "H5Pcreate");
+    if (dcpl_g == H5P_DEFAULT) {
+        dcpl = H5Pcreate(H5P_DATASET_CREATE);
+        CHECK(dcpl, FAIL, "H5Pcreate");
+    } else {
+        dcpl = H5Pcopy(dcpl_g);
+        CHECK(dcpl, FAIL, "H5Pcopy");
+    }
 
     /* Set attribute creation order tracking & indexing for object */
     ret = H5Pset_attr_creation_order(dcpl, (H5P_CRT_ORDER_TRACKED | H5P_CRT_ORDER_INDEXED));
@@ -4950,8 +5046,13 @@ test_attr_corder_transition(hid_t fcpl, hid_t fapl)
     CHECK(fid, FAIL, "H5Fcreate");
 
     /* Create dataset creation property list */
-    dcpl = H5Pcreate(H5P_DATASET_CREATE);
-    CHECK(dcpl, FAIL, "H5Pcreate");
+    if (dcpl_g == H5P_DEFAULT) {
+        dcpl = H5Pcreate(H5P_DATASET_CREATE);
+        CHECK(dcpl, FAIL, "H5Pcreate");
+    } else {
+        dcpl = H5Pcopy(dcpl_g);
+        CHECK(dcpl, FAIL, "H5Pcopy");
+    }
 
     /* Set attribute creation order tracking & indexing for object */
     ret = H5Pset_attr_creation_order(dcpl, (H5P_CRT_ORDER_TRACKED | H5P_CRT_ORDER_INDEXED));
@@ -5361,8 +5462,13 @@ test_attr_corder_delete(hid_t fcpl, hid_t fapl)
     CHECK(sid, FAIL, "H5Screate");
 
     /* Create dataset creation property list */
-    dcpl = H5Pcreate(H5P_DATASET_CREATE);
-    CHECK(dcpl, FAIL, "H5Pcreate");
+    if (dcpl_g == H5P_DEFAULT) {
+        dcpl = H5Pcreate(H5P_DATASET_CREATE);
+        CHECK(dcpl, FAIL, "H5Pcreate");
+    } else {
+        dcpl = H5Pcopy(dcpl_g);
+        CHECK(dcpl, FAIL, "H5Pcopy");
+    }
 
     /* Set attribute creation order tracking & indexing for object */
     ret = H5Pset_attr_creation_order(dcpl, (H5P_CRT_ORDER_TRACKED | H5P_CRT_ORDER_INDEXED));
@@ -5704,8 +5810,13 @@ test_attr_info_by_idx(hbool_t new_format, hid_t fcpl, hid_t fapl)
     CHECK(sid, FAIL, "H5Screate");
 
     /* Create dataset creation property list */
-    dcpl = H5Pcreate(H5P_DATASET_CREATE);
-    CHECK(dcpl, FAIL, "H5Pcreate");
+    if (dcpl_g == H5P_DEFAULT) {
+        dcpl = H5Pcreate(H5P_DATASET_CREATE);
+        CHECK(dcpl, FAIL, "H5Pcreate");
+    } else {
+        dcpl = H5Pcopy(dcpl_g);
+        CHECK(dcpl, FAIL, "H5Pcopy");
+    }
 
     /* Query the attribute creation properties */
     ret = H5Pget_attr_phase_change(dcpl, &max_compact, &min_dense);
@@ -5894,7 +6005,7 @@ test_attr_info_null_info_pointer(hid_t fcpl, hid_t fapl)
     hid_t  attr;
     hid_t  sid;
 
-    /* Create dataspace for dataset & attributes */
+    /* Create dataspace for attribute */
     sid = H5Screate(H5S_SCALAR);
     CHECK(sid, FAIL, "H5Screate");
 
@@ -5938,6 +6049,95 @@ test_attr_info_null_info_pointer(hid_t fcpl, hid_t fapl)
 }
 
 
+/***************************************************************
+**
+**  test_attr_rename_invalid_name(): A test to ensure that
+**      passing a NULL or empty attribute name to
+**      H5Arename(_by_name) doesn't cause bad behavior.
+**
+****************************************************************/
+static void
+test_attr_rename_invalid_name(hid_t fcpl, hid_t fapl)
+{
+    herr_t err_ret = -1;
+    hid_t  fid;
+    hid_t  attr;
+    hid_t  sid;
+
+    /* Create dataspace for attribute */
+    sid = H5Screate(H5S_SCALAR);
+    CHECK(sid, FAIL, "H5Screate");
+
+    /* Create file */
+    fid = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl, fapl);
+    CHECK(fid, FAIL, "H5Fcreate");
+
+    /* Create attribute */
+    attr = H5Acreate2(fid, INVALID_RENAME_TEST_ATTR_NAME, H5T_NATIVE_UINT, sid, H5P_DEFAULT, H5P_DEFAULT);
+    CHECK(attr, FAIL, "H5Acreate2");
+
+    H5E_BEGIN_TRY {
+        err_ret = H5Arename(fid, NULL, INVALID_RENAME_TEST_NEW_ATTR_NAME);
+    } H5E_END_TRY;
+
+    CHECK(err_ret, SUCCEED, "H5Arename");
+
+    H5E_BEGIN_TRY {
+        err_ret = H5Arename(fid, "", INVALID_RENAME_TEST_NEW_ATTR_NAME);
+    } H5E_END_TRY;
+
+    CHECK(err_ret, SUCCEED, "H5Arename");
+
+    H5E_BEGIN_TRY {
+        err_ret = H5Arename(fid, INVALID_RENAME_TEST_ATTR_NAME, NULL);
+    } H5E_END_TRY;
+
+    CHECK(err_ret, SUCCEED, "H5Arename");
+
+    H5E_BEGIN_TRY {
+        err_ret = H5Arename(fid, INVALID_RENAME_TEST_ATTR_NAME, "");
+    } H5E_END_TRY;
+
+    CHECK(err_ret, SUCCEED, "H5Arename");
+
+    H5E_BEGIN_TRY {
+        err_ret = H5Arename_by_name(fid, ".", NULL, INVALID_RENAME_TEST_NEW_ATTR_NAME, H5P_DEFAULT);
+    } H5E_END_TRY;
+
+    CHECK(err_ret, SUCCEED, "H5Arename_by_name");
+
+    H5E_BEGIN_TRY {
+        err_ret = H5Arename_by_name(fid, ".", "", INVALID_RENAME_TEST_NEW_ATTR_NAME, H5P_DEFAULT);
+    } H5E_END_TRY;
+
+    CHECK(err_ret, SUCCEED, "H5Arename_by_name");
+
+    H5E_BEGIN_TRY {
+        err_ret = H5Arename_by_name(fid, ".", INVALID_RENAME_TEST_ATTR_NAME, NULL, H5P_DEFAULT);
+    } H5E_END_TRY;
+
+    CHECK(err_ret, SUCCEED, "H5Arename_by_name");
+
+    H5E_BEGIN_TRY {
+        err_ret = H5Arename_by_name(fid, ".", INVALID_RENAME_TEST_ATTR_NAME, "", H5P_DEFAULT);
+    } H5E_END_TRY;
+
+    CHECK(err_ret, SUCCEED, "H5Arename_by_name");
+
+    /* Close dataspace */
+    err_ret = H5Sclose(sid);
+    CHECK(err_ret, FAIL, "H5Sclose");
+
+    /* Close attribute */
+    err_ret = H5Aclose(attr);
+    CHECK(err_ret, FAIL, "H5Aclose");
+
+    /* Close file */
+    err_ret = H5Fclose(fid);
+    CHECK(err_ret, FAIL, "H5Fclose");
+}
+
+
 /****************************************************************
 **
 **  test_attr_delete_by_idx(): Test basic H5A (attribute) code.
@@ -5975,8 +6175,13 @@ test_attr_delete_by_idx(hbool_t new_format, hid_t fcpl, hid_t fapl)
     CHECK(sid, FAIL, "H5Screate");
 
     /* Create dataset creation property list */
-    dcpl = H5Pcreate(H5P_DATASET_CREATE);
-    CHECK(dcpl, FAIL, "H5Pcreate");
+    if (dcpl_g == H5P_DEFAULT) {
+        dcpl = H5Pcreate(H5P_DATASET_CREATE);
+        CHECK(dcpl, FAIL, "H5Pcreate");
+    } else {
+        dcpl = H5Pcopy(dcpl_g);
+        CHECK(dcpl, FAIL, "H5Pcopy");
+    }
 
     /* Query the attribute creation properties */
     ret = H5Pget_attr_phase_change(dcpl, &max_compact, &min_dense);
@@ -6918,8 +7123,13 @@ test_attr_iterate2(hbool_t new_format, hid_t fcpl, hid_t fapl)
     CHECK(sid, FAIL, "H5Screate");
 
     /* Create dataset creation property list */
-    dcpl = H5Pcreate(H5P_DATASET_CREATE);
-    CHECK(dcpl, FAIL, "H5Pcreate");
+    if (dcpl_g == H5P_DEFAULT) {
+        dcpl = H5Pcreate(H5P_DATASET_CREATE);
+        CHECK(dcpl, FAIL, "H5Pcreate");
+    } else {
+        dcpl = H5Pcopy(dcpl_g);
+        CHECK(dcpl, FAIL, "H5Pcopy");
+    }
 
     /* Query the attribute creation properties */
     ret = H5Pget_attr_phase_change(dcpl, &max_compact, &min_dense);
@@ -7279,8 +7489,13 @@ test_attr_open_by_idx(hbool_t new_format, hid_t fcpl, hid_t fapl)
     CHECK(sid, FAIL, "H5Screate");
 
     /* Create dataset creation property list */
-    dcpl = H5Pcreate(H5P_DATASET_CREATE);
-    CHECK(dcpl, FAIL, "H5Pcreate");
+    if (dcpl_g == H5P_DEFAULT) {
+        dcpl = H5Pcreate(H5P_DATASET_CREATE);
+        CHECK(dcpl, FAIL, "H5Pcreate");
+    } else {
+        dcpl = H5Pcopy(dcpl_g);
+        CHECK(dcpl, FAIL, "H5Pcopy");
+    }
 
     /* Query the attribute creation properties */
     ret = H5Pget_attr_phase_change(dcpl, &max_compact, &min_dense);
@@ -7626,8 +7841,13 @@ test_attr_open_by_name(hbool_t new_format, hid_t fcpl, hid_t fapl)
     CHECK(sid, FAIL, "H5Screate");
 
     /* Create dataset creation property list */
-    dcpl = H5Pcreate(H5P_DATASET_CREATE);
-    CHECK(dcpl, FAIL, "H5Pcreate");
+    if (dcpl_g == H5P_DEFAULT) {
+        dcpl = H5Pcreate(H5P_DATASET_CREATE);
+        CHECK(dcpl, FAIL, "H5Pcreate");
+    } else {
+        dcpl = H5Pcopy(dcpl_g);
+        CHECK(dcpl, FAIL, "H5Pcopy");
+    }
 
     /* Query the attribute creation properties */
     ret = H5Pget_attr_phase_change(dcpl, &max_compact, &min_dense);
@@ -7880,8 +8100,13 @@ test_attr_create_by_name(hbool_t new_format, hid_t fcpl, hid_t fapl)
     CHECK(sid, FAIL, "H5Screate");
 
     /* Create dataset creation property list */
-    dcpl = H5Pcreate(H5P_DATASET_CREATE);
-    CHECK(dcpl, FAIL, "H5Pcreate");
+    if (dcpl_g == H5P_DEFAULT) {
+        dcpl = H5Pcreate(H5P_DATASET_CREATE);
+        CHECK(dcpl, FAIL, "H5Pcreate");
+    } else {
+        dcpl = H5Pcopy(dcpl_g);
+        CHECK(dcpl, FAIL, "H5Pcopy");
+    }
 
     /* Query the attribute creation properties */
     ret = H5Pget_attr_phase_change(dcpl, &max_compact, &min_dense);
@@ -8181,8 +8406,13 @@ test_attr_shared_write(hid_t fcpl, hid_t fapl)
         } /* end if */
 
         /* Set up to query the object creation properties */
-        dcpl = H5Pcreate(H5P_DATASET_CREATE);
-        CHECK(dcpl, FAIL, "H5Pcreate");
+        if (dcpl_g == H5P_DEFAULT) {
+            dcpl = H5Pcreate(H5P_DATASET_CREATE);
+            CHECK(dcpl, FAIL, "H5Pcreate");
+        } else {
+            dcpl = H5Pcopy(dcpl_g);
+            CHECK(dcpl, FAIL, "H5Pcopy");
+        }
 
         /* Create datasets */
         dataset = H5Dcreate2(fid, DSET1_NAME, H5T_NATIVE_UCHAR, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT);
@@ -8512,8 +8742,13 @@ test_attr_shared_rename(hid_t fcpl, hid_t fapl)
         } /* end if */
 
         /* Set up to query the object creation properties */
-        dcpl = H5Pcreate(H5P_DATASET_CREATE);
-        CHECK(dcpl, FAIL, "H5Pcreate");
+        if (dcpl_g == H5P_DEFAULT) {
+            dcpl = H5Pcreate(H5P_DATASET_CREATE);
+            CHECK(dcpl, FAIL, "H5Pcreate");
+        } else {
+            dcpl = H5Pcopy(dcpl_g);
+            CHECK(dcpl, FAIL, "H5Pcopy");
+        }
 
         /* Create datasets */
         dataset = H5Dcreate2(fid, DSET1_NAME, H5T_NATIVE_UCHAR, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT);
@@ -8958,8 +9193,13 @@ test_attr_shared_delete(hid_t fcpl, hid_t fapl)
         } /* end if */
 
         /* Set up to query the object creation properties */
-        dcpl = H5Pcreate(H5P_DATASET_CREATE);
-        CHECK(dcpl, FAIL, "H5Pcreate");
+        if (dcpl_g == H5P_DEFAULT) {
+            dcpl = H5Pcreate(H5P_DATASET_CREATE);
+            CHECK(dcpl, FAIL, "H5Pcreate");
+        } else {
+            dcpl = H5Pcopy(dcpl_g);
+            CHECK(dcpl, FAIL, "H5Pcopy");
+        }
 
         /* Create datasets */
         dataset = H5Dcreate2(fid, DSET1_NAME, H5T_NATIVE_UCHAR, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT);
@@ -9327,8 +9567,13 @@ test_attr_shared_unlink(hid_t fcpl, hid_t fapl)
         } /* end if */
 
         /* Set up to query the object creation properties */
-        dcpl = H5Pcreate(H5P_DATASET_CREATE);
-        CHECK(dcpl, FAIL, "H5Pcreate");
+        if (dcpl_g == H5P_DEFAULT) {
+            dcpl = H5Pcreate(H5P_DATASET_CREATE);
+            CHECK(dcpl, FAIL, "H5Pcreate");
+        } else {
+            dcpl = H5Pcopy(dcpl_g);
+            CHECK(dcpl, FAIL, "H5Pcopy");
+        }
 
         /* Create datasets */
         dataset = H5Dcreate2(fid, DSET1_NAME, H5T_NATIVE_UCHAR, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT);
@@ -9919,7 +10164,7 @@ test_attr_bug3(hid_t fcpl, hid_t fapl)
     CHECK(ret, FAIL, "H5Tcommit2");
 
     /* Create dataset */
-    did = H5Dcreate2(fid, "dset", tid2, sid2, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    did = H5Dcreate2(fid, "dset", tid2, sid2, H5P_DEFAULT, dcpl_g, H5P_DEFAULT);
     CHECK(did, FAIL, "H5Dcreate2");
 
     /* Create attribute on datatype, using that datatype as its datatype */
@@ -10054,7 +10299,7 @@ test_attr_bug4(hid_t fcpl, hid_t fapl)
     CHECK(ret, FAIL, "H5Tcommit2");
 
     /* Create dataset */
-    did = H5Dcreate2(fid, "dset", tid, sid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    did = H5Dcreate2(fid, "dset", tid, sid, H5P_DEFAULT, dcpl_g, H5P_DEFAULT);
     CHECK(did, FAIL, "H5Dcreate2");
 
     /* Create attributes on group and dataset */
@@ -10136,7 +10381,7 @@ test_attr_bug5(hid_t fcpl, hid_t fapl)
     CHECK(ret, FAIL, "H5Tcommit2");
 
     /* Create dataset */
-    did1 = H5Dcreate2(fid1, BUG3_DSET_NAME, tid1, sid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    did1 = H5Dcreate2(fid1, BUG3_DSET_NAME, tid1, sid, H5P_DEFAULT, dcpl_g, H5P_DEFAULT);
     CHECK(did1, FAIL, "H5Dcreate2");
 
     /* Create attribute on root group */
@@ -10834,121 +11079,106 @@ test_attr(void)
 {
     hid_t    fapl = (-1), fapl2 = (-1);    /* File access property lists */
     hid_t    fcpl = (-1), fcpl2 = (-1);    /* File creation property lists */
-    unsigned new_format;        /* Whether to use the new format or not */
-    unsigned use_shared;        /* Whether to use shared attributes or not */
-    herr_t ret;                 /* Generic return value */
+    hid_t    dcpl = -1;
+    unsigned new_format;       /* Whether to use the new format or not */
+    unsigned use_shared;       /* Whether to use shared attributes or not */
+    unsigned minimize_dset_oh; /* Whether to use minimized dataset object headers */
+    herr_t ret;                /* Generic return value */
 
-    /* Output message about test being performed */
     MESSAGE(5, ("Testing Attributes\n"));
 
-    /* Create a default file access property list */
     fapl = H5Pcreate(H5P_FILE_ACCESS);
     CHECK(fapl, FAIL, "H5Pcreate");
 
-    /* Copy the file access property list */
     fapl2 = H5Pcopy(fapl);
     CHECK(fapl2, FAIL, "H5Pcopy");
-
-    /* Set the "use the latest version of the format" bounds for creating objects in the file */
     ret = H5Pset_libver_bounds(fapl2, H5F_LIBVER_LATEST, H5F_LIBVER_LATEST);
     CHECK(ret, FAIL, "H5Pset_libver_bounds");
 
-    /* Create a default file creation property list */
     fcpl = H5Pcreate(H5P_FILE_CREATE);
     CHECK(fcpl, FAIL, "H5Pcreate");
 
-    /* Copy the file creation property list */
+    /* files with fcpl2 make all attributes ( > 1 byte) shared
+     * (i.e. all of them :-) */
     fcpl2 = H5Pcopy(fcpl);
     CHECK(fcpl2, FAIL, "H5Pcopy");
-
-    /* Make attributes > 1 byte shared (i.e. all of them :-) */
     ret = H5Pset_shared_mesg_nindexes(fcpl2, (unsigned)1);
     CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
     ret = H5Pset_shared_mesg_index(fcpl2, (unsigned)0, H5O_SHMESG_ATTR_FLAG, (unsigned)1);
     CHECK_I(ret, "H5Pset_shared_mesg_index");
 
-    /* Loop over using new group format */
-    for(new_format = FALSE; new_format <= TRUE; new_format++) {
-        hid_t my_fapl;
+    for(minimize_dset_oh = 0; minimize_dset_oh <= 1; minimize_dset_oh++) {
+        if(minimize_dset_oh == 0) {
+            MESSAGE(7, ("testing with default dataset object headers\n"));
+            dcpl_g = H5P_DEFAULT;
+        } else {
+            MESSAGE(7, ("testing with minimzied dataset object headers\n"));
+            dcpl = H5Pcreate(H5P_DATASET_CREATE);
+            CHECK(dcpl, FAIL, "H5Pcreate");
+            ret = H5Pset_dset_no_attrs_hint(dcpl, TRUE);
+            CHECK_I(ret, "H5Pset_dset_no_attrs_hint");
+            dcpl_g = dcpl;
+        }
+
+        for(new_format = FALSE; new_format <= TRUE; new_format++) {
+            hid_t my_fapl;
 
-        /* Set the FAPL for the type of format */
-        if(new_format) {
-            MESSAGE(7, ("testing with new file format\n"));
-            my_fapl = fapl2;
-        } /* end if */
-        else {
-            MESSAGE(7, ("testing with old file format\n"));
-            my_fapl = fapl;
-        } /* end else */
+            if(new_format) {
+                MESSAGE(7, ("testing with new file format\n"));
+                my_fapl = fapl2;
+            } else {
+                MESSAGE(7, ("testing with old file format\n"));
+                my_fapl = fapl;
+            }
 
-        /* These next two tests use the same file information */
-        test_attr_basic_write(my_fapl);    /* Test basic H5A writing code */
-        test_attr_basic_read(my_fapl);     /* Test basic H5A reading code */
+            /* These next two tests use the same file information */
+            test_attr_basic_write(my_fapl);    /* Test basic H5A writing code */
+            test_attr_basic_read(my_fapl);     /* Test basic H5A reading code */
 
-        /* These next two tests use their own file information */
-        test_attr_flush(my_fapl);          /* Test H5A I/O in the presence of H5Fflush calls */
-        test_attr_plist(my_fapl);          /* Test attribute property lists */
+            /* These next two tests use their own file information */
+            test_attr_flush(my_fapl);          /* Test H5A I/O in the presence of H5Fflush calls */
+            test_attr_plist(my_fapl);          /* Test attribute property lists */
 
-        /* These next two tests use the same file information */
-        test_attr_compound_write(my_fapl);  /* Test complex datatype H5A writing code */
-        test_attr_compound_read(my_fapl);   /* Test complex datatype H5A reading code */
+            /* These next two tests use the same file information */
+            test_attr_compound_write(my_fapl);  /* Test complex datatype H5A writing code */
+            test_attr_compound_read(my_fapl);   /* Test complex datatype H5A reading code */
 
-        /* These next two tests use the same file information */
-        test_attr_scalar_write(my_fapl);  /* Test scalar dataspace H5A writing code */
-        test_attr_scalar_read(my_fapl);   /* Test scalar dataspace H5A reading code */
+            /* These next two tests use the same file information */
+            test_attr_scalar_write(my_fapl);  /* Test scalar dataspace H5A writing code */
+            test_attr_scalar_read(my_fapl);   /* Test scalar dataspace H5A reading code */
 
-        /* These next four tests use the same file information */
-        test_attr_mult_write(my_fapl);     /* Test H5A writing code for multiple attributes */
-        test_attr_mult_read(my_fapl);      /* Test H5A reading code for multiple attributes */
-        test_attr_iterate(my_fapl);        /* Test H5A iterator code */
-        test_attr_delete(my_fapl);         /* Test H5A code for deleting attributes */
+            /* These next four tests use the same file information */
+            test_attr_mult_write(my_fapl);     /* Test H5A writing code for multiple attributes */
+            test_attr_mult_read(my_fapl);      /* Test H5A reading code for multiple attributes */
+            test_attr_iterate(my_fapl);        /* Test H5A iterator code */
+            test_attr_delete(my_fapl);         /* Test H5A code for deleting attributes */
 
-        /* This next test uses its own file information */
-        test_attr_dtype_shared(my_fapl);   /* Test using shared dataypes in attributes */
+            /* This next test uses its own file information */
+            test_attr_dtype_shared(my_fapl);   /* Test using shared dataypes in attributes */
 
-        /* This next test uses its own file information */
-        test_attr_duplicate_ids(my_fapl);
+            /* This next test uses its own file information */
+            test_attr_duplicate_ids(my_fapl);
 
-        /* Tests on "new format" attribute storage */
-        if(new_format == TRUE) {
-            /* Loop over using shared attributes */
             for(use_shared = FALSE; use_shared <= TRUE; use_shared++) {
                 hid_t my_fcpl;
 
-                /* Set the FCPL for shared or not */
-                if(use_shared) {
+                if(new_format == TRUE && use_shared) {
                     MESSAGE(7, ("testing with shared attributes\n"));
                     my_fcpl = fcpl2;
-                } /* end if */
-                else {
+                } else {
                     MESSAGE(7, ("testing without shared attributes\n"));
                     my_fcpl = fcpl;
-                } /* end else */
-
-                /* General attribute tests */
-                test_attr_dense_create(my_fcpl, my_fapl);       /* Test dense attribute storage creation */
-                test_attr_dense_open(my_fcpl, my_fapl);         /* Test opening attributes in dense storage */
-                test_attr_dense_delete(my_fcpl, my_fapl);       /* Test deleting attributes in dense storage */
-                test_attr_dense_rename(my_fcpl, my_fapl);       /* Test renaming attributes in dense storage */
-                test_attr_dense_unlink(my_fcpl, my_fapl);       /* Test unlinking object with attributes in dense storage */
-                test_attr_dense_limits(my_fcpl, my_fapl);       /* Test dense attribute storage limits */
-                test_attr_dense_dup_ids(my_fcpl, my_fapl);      /* Test duplicated IDs for dense attribute storage */
+                }
 
                 test_attr_big(my_fcpl, my_fapl);                /* Test storing big attribute */
                 test_attr_null_space(my_fcpl, my_fapl);         /* Test storing attribute with NULL dataspace */
                 test_attr_deprec(fcpl, my_fapl);                /* Test deprecated API routines */
                 test_attr_many(new_format, my_fcpl, my_fapl);               /* Test storing lots of attributes */
                 test_attr_info_null_info_pointer(my_fcpl, my_fapl); /* Test passing a NULL attribute info pointer to H5Aget_info(_by_name/_by_idx) */
+                test_attr_rename_invalid_name(my_fcpl, my_fapl); /* Test passing a NULL or empty attribute name to H5Arename(_by_name) */
 
-                /* Attribute creation order tests */
-                test_attr_corder_create_basic(my_fcpl, my_fapl);/* Test creating an object w/attribute creation order info */
-                test_attr_corder_create_compact(my_fcpl, my_fapl);  /* Test compact attribute storage on an object w/attribute creation order info */
-                test_attr_corder_create_dense(my_fcpl, my_fapl);/* Test dense attribute storage on an object w/attribute creation order info */
-                test_attr_corder_create_reopen(my_fcpl, my_fapl);/* Test creating attributes w/reopening file from using new format to using old format */
-                test_attr_corder_transition(my_fcpl, my_fapl);  /* Test attribute storage transitions on an object w/attribute creation order info */
-                test_attr_corder_delete(my_fcpl, my_fapl);      /* Test deleting object using dense storage w/attribute creation order info */
-
-                /* New attribute API routine tests */
+                /* New attribute API routine tests
+                 */
                 test_attr_info_by_idx(new_format, my_fcpl, my_fapl);    /* Test querying attribute info by index */
                 test_attr_delete_by_idx(new_format, my_fcpl, my_fapl);  /* Test deleting attribute by index */
                 test_attr_iterate2(new_format, my_fcpl, my_fapl);       /* Test iterating over attributes by index */
@@ -10956,57 +11186,68 @@ test_attr(void)
                 test_attr_open_by_name(new_format, my_fcpl, my_fapl);   /* Test opening attributes by name */
                 test_attr_create_by_name(new_format, my_fcpl, my_fapl); /* Test creating attributes by name */
 
-                /* More complex tests with both "new format" and "shared" attributes */
-                if(use_shared == TRUE) {
-                    test_attr_shared_write(my_fcpl, my_fapl);   /* Test writing to shared attributes in compact & dense storage */
-                    test_attr_shared_rename(my_fcpl, my_fapl);  /* Test renaming shared attributes in compact & dense storage */
-                    test_attr_shared_delete(my_fcpl, my_fapl);  /* Test deleting shared attributes in compact & dense storage */
-                    test_attr_shared_unlink(my_fcpl, my_fapl);  /* Test unlinking object with shared attributes in compact & dense storage */
-                } /* end if */
-
-                /* Tests that address specific bugs */
+                /* Tests that address specific bugs
+                 */
                 test_attr_bug1(my_fcpl, my_fapl);               /* Test odd allocation operations */
                 test_attr_bug2(my_fcpl, my_fapl);               /* Test many deleted attributes */
                 test_attr_bug3(my_fcpl, my_fapl);               /* Test "self referential" attributes */
                 test_attr_bug4(my_fcpl, my_fapl);               /* Test attributes on named datatypes */
                 test_attr_bug5(my_fcpl, my_fapl);               /* Test opening/closing attributes through different file handles */
                 test_attr_bug6(my_fcpl, my_fapl);               /* Test reading empty attribute */
-                test_attr_bug7(my_fcpl, my_fapl);               /* Test creating and deleting large attributes in ohdr chunk 0 */
+                /* test_attr_bug7 is specific to the "new" object header format,
+                 * and in fact fails if used with the old format due to the
+                 * attributes being larger than 64K */
                 test_attr_bug8(my_fcpl, my_fapl);               /* Test attribute expanding object header with undecoded messages */
                 test_attr_bug9(my_fcpl, my_fapl);               /* Test large attributes converting to dense storage */
-                test_attr_delete_last_dense(my_fcpl, my_fapl);  /* Test */
-            } /* end for */
-        } /* end if */
-        else {
-            /* General attribute tests */
-            test_attr_big(fcpl, my_fapl);                       /* Test storing big attribute */
-            test_attr_null_space(fcpl, my_fapl);                /* Test storing attribute with NULL dataspace */
-            test_attr_deprec(fcpl, my_fapl);                    /* Test deprecated API routines */
-            test_attr_many(new_format, fcpl, my_fapl);               /* Test storing lots of attributes */
-            test_attr_info_null_info_pointer(fcpl, my_fapl); /* Test passing a NULL attribute info pointer to H5Aget_info(_by_name/_by_idx) */
-
-            /* New attribute API routine tests, on old-format storage */
-            test_attr_info_by_idx(new_format, fcpl, my_fapl);   /* Test querying attribute info by index */
-            test_attr_delete_by_idx(new_format, fcpl, my_fapl); /* Test deleting attribute by index */
-            test_attr_iterate2(new_format, fcpl, my_fapl);      /* Test iterating over attributes by index */
-            test_attr_open_by_idx(new_format, fcpl, my_fapl);   /* Test opening attributes by index */
-            test_attr_open_by_name(new_format, fcpl, my_fapl);  /* Test opening attributes by name */
-            test_attr_create_by_name(new_format, fcpl, my_fapl); /* Test creating attributes by name */
-
-            /* Tests that address specific bugs */
-            test_attr_bug1(fcpl, my_fapl);                      /* Test odd allocation operations */
-            test_attr_bug2(fcpl, my_fapl);                      /* Test many deleted attributes */
-            test_attr_bug3(fcpl, my_fapl);                      /* Test "self referential" attributes */
-            test_attr_bug4(fcpl, my_fapl);                      /* Test attributes on named datatypes */
-            test_attr_bug5(fcpl, my_fapl);                      /* Test opening/closing attributes through different file handles */
-            test_attr_bug6(fcpl, my_fapl);                      /* Test reading empty attribute */
-            /* Skip test_attr_bug7 because it is specific to the new object
-             * header format and in fact fails if used with the old format, due
-             * to the attributes being larger than 64K */
-            test_attr_bug8(fcpl, my_fapl);                      /* Test attribute expanding object header with undecoded messages */
-            test_attr_bug9(fcpl, my_fapl);                      /* Test large attributes converting to dense storage */
-        } /* end else */
-    } /* end for */
+
+                /* tests specific to the "new format"
+                 */
+                if (new_format == TRUE) {
+                    /* General attribute tests */
+                    test_attr_dense_create(my_fcpl, my_fapl);       /* Test dense attribute storage creation */
+                    test_attr_dense_open(my_fcpl, my_fapl);         /* Test opening attributes in dense storage */
+                    test_attr_dense_delete(my_fcpl, my_fapl);       /* Test deleting attributes in dense storage */
+                    test_attr_dense_rename(my_fcpl, my_fapl);       /* Test renaming attributes in dense storage */
+                    test_attr_dense_unlink(my_fcpl, my_fapl);       /* Test unlinking object with attributes in dense storage */
+                    test_attr_dense_limits(my_fcpl, my_fapl);       /* Test dense attribute storage limits */
+                    test_attr_dense_dup_ids(my_fcpl, my_fapl);      /* Test duplicated IDs for dense attribute storage */
+
+                    /* Attribute creation order tests
+                     */
+                    test_attr_corder_create_basic(my_fcpl, my_fapl);/* Test creating an object w/attribute creation order info */
+                    test_attr_corder_create_compact(my_fcpl, my_fapl);  /* Test compact attribute storage on an object w/attribute creation order info */
+                    test_attr_corder_create_dense(my_fcpl, my_fapl);/* Test dense attribute storage on an object w/attribute creation order info */
+                    test_attr_corder_create_reopen(my_fcpl, my_fapl);/* Test creating attributes w/reopening file from using new format to using old format */
+                    test_attr_corder_transition(my_fcpl, my_fapl);  /* Test attribute storage transitions on an object w/attribute creation order info */
+                    test_attr_corder_delete(my_fcpl, my_fapl);      /* Test deleting object using dense storage w/attribute creation order info */
+
+                    /* More complex tests with exclusively both "new format" and "shared" attributes
+                     */
+                    if(use_shared == TRUE) {
+                        test_attr_shared_write(my_fcpl, my_fapl);   /* Test writing to shared attributes in compact & dense storage */
+                        test_attr_shared_rename(my_fcpl, my_fapl);  /* Test renaming shared attributes in compact & dense storage */
+                        test_attr_shared_delete(my_fcpl, my_fapl);  /* Test deleting shared attributes in compact & dense storage */
+                        test_attr_shared_unlink(my_fcpl, my_fapl);  /* Test unlinking object with shared attributes in compact & dense storage */
+                    } /* if using shared attributes */
+
+                    test_attr_delete_last_dense(my_fcpl, my_fapl);
+
+                    /* test_attr_bug7 is specific to the "new" object header format,
+                     * and in fact fails if used with the old format due to the
+                     * attributes being larger than 64K */
+                    test_attr_bug7(my_fcpl, my_fapl);               /* Test creating and deleting large attributes in ohdr chunk 0 */
+
+                } /* if using "new format" */
+            } /* for unshared/shared attributes */
+        } /* for old/new format */
+
+        if (minimize_dset_oh != 0) {
+            ret = H5Pclose(dcpl);
+            CHECK(ret, FAIL, "H5Pclose");
+            dcpl_g = H5P_DEFAULT;
+        }
+
+    } /* for default/minimized dataset object headers */
 
     /* Close  FCPLs */
     ret = H5Pclose(fcpl);
diff --git a/test/test_vol_plugin.sh.in b/test/test_vol_plugin.sh.in
new file mode 100644
index 0000000..38220ef
--- /dev/null
+++ b/test/test_vol_plugin.sh.in
@@ -0,0 +1,84 @@
+#! /bin/sh
+#
+# Copyright by The HDF Group.                                              
+# All rights reserved.                                                     
+#                                                                          
+# This file is part of HDF5. The full HDF5 copyright notice, including     
+# terms governing use, modification, and redistribution, is contained in   
+# the COPYING file, which can be found at the root of the source code
+# distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.
+# If you do not have access to either file, you may request a copy from
+# help@hdfgroup.org.
+#
+# This shell script is for testing VOL connector plugins.
+#
+srcdir=@srcdir@
+TOP_BUILDDIR=@top_builddir@
+
+EXIT_SUCCESS=0
+EXIT_FAILURE=1
+
+nerrors=0
+verbose=yes
+exit_code=$EXIT_SUCCESS
+
+TEST_NAME=vol_plugin
+TEST_BIN=`pwd`/$TEST_NAME
+FROM_DIR=`pwd`/.libs
+case $(uname) in
+    CYGWIN* )
+        NULL_VOL_PLUGIN="$FROM_DIR/cygnull_vol_connector*"
+        ;;
+    *)
+        NULL_VOL_PLUGIN="$FROM_DIR/libnull_vol_connector*"
+        ;;
+esac
+TEMP_PLUGIN_DIR=null_vol_plugin_dir
+CP="cp -p"    # Use -p to preserve mode,ownership, timestamps
+RM="rm -rf"
+
+# Print a line-line message left justified in a field of 70 characters
+# beginning with the word "Testing".
+#
+TESTING() {
+    SPACES="                                                               "
+    echo "Testing $* $SPACES" | cut -c1-70 | tr -d '\012'
+}
+
+# Main Body
+# Create test directory if necessary.
+test -d $TEMP_PLUGIN_DIR || mkdir -p $TEMP_PLUGIN_DIR
+if [ $? != 0 ]; then
+    echo "Failed to create VOL connector plugin test directory ($TEMP_PLUGIN_DIR)"
+    exit $EXIT_FAILURE
+fi
+
+# Copy plugin for the tests.
+$CP $NULL_VOL_PLUGIN $TEMP_PLUGIN_DIR
+if [ $? != 0 ]; then
+    echo "Failed to copy NULL VOL plugin ($NULL_VOL_PLUGIN) to test directory."
+    exit $EXIT_FAILURE
+fi
+
+# setup plugin path
+ENVCMD="env HDF5_PLUGIN_PATH=${TEMP_PLUGIN_DIR}"
+
+# Run the test
+$ENVCMD $TEST_BIN
+if [ $? != 0 ]; then
+    nerrors=`expr $nerrors + 1`
+fi
+
+# print results
+if test $nerrors -ne 0 ; then
+    echo "$nerrors errors encountered"
+    exit_code=$EXIT_FAILURE
+else
+    echo "All VOL plugin tests passed."
+    exit_code=$EXIT_SUCCESS
+fi
+
+# Clean up temporary files/directories and leave
+$RM $TEMP_PLUGIN_DIR
+
+exit $exit_code
diff --git a/test/testfiles/plist_files/def_fapl_32be b/test/testfiles/plist_files/def_fapl_32be
index 6e94011..53ef572 100644
--- a/test/testfiles/plist_files/def_fapl_32be
+++ b/test/testfiles/plist_files/def_fapl_32be
diff --git a/test/testfiles/plist_files/def_fapl_32le b/test/testfiles/plist_files/def_fapl_32le
index 6e94011..53ef572 100644
--- a/test/testfiles/plist_files/def_fapl_32le
+++ b/test/testfiles/plist_files/def_fapl_32le
diff --git a/test/testfiles/plist_files/def_fapl_64be b/test/testfiles/plist_files/def_fapl_64be
index 6e94011..53ef572 100644
--- a/test/testfiles/plist_files/def_fapl_64be
+++ b/test/testfiles/plist_files/def_fapl_64be
diff --git a/test/testfiles/plist_files/def_fapl_64le b/test/testfiles/plist_files/def_fapl_64le
index 6e94011..53ef572 100644
--- a/test/testfiles/plist_files/def_fapl_64le
+++ b/test/testfiles/plist_files/def_fapl_64le
diff --git a/test/testfiles/plist_files/fapl_32be b/test/testfiles/plist_files/fapl_32be
index 237b291..d89a44c 100644
--- a/test/testfiles/plist_files/fapl_32be
+++ b/test/testfiles/plist_files/fapl_32be
diff --git a/test/testfiles/plist_files/fapl_32le b/test/testfiles/plist_files/fapl_32le
index 237b291..d89a44c 100644
--- a/test/testfiles/plist_files/fapl_32le
+++ b/test/testfiles/plist_files/fapl_32le
diff --git a/test/testfiles/plist_files/fapl_64be b/test/testfiles/plist_files/fapl_64be
index 237b291..d89a44c 100644
--- a/test/testfiles/plist_files/fapl_64be
+++ b/test/testfiles/plist_files/fapl_64be
diff --git a/test/testfiles/plist_files/fapl_64le b/test/testfiles/plist_files/fapl_64le
index 237b291..d89a44c 100644
--- a/test/testfiles/plist_files/fapl_64le
+++ b/test/testfiles/plist_files/fapl_64le
diff --git a/test/testfiles/plist_files/lapl_32be b/test/testfiles/plist_files/lapl_32be
index 9d81759..eee238e 100644
--- a/test/testfiles/plist_files/lapl_32be
+++ b/test/testfiles/plist_files/lapl_32be
diff --git a/test/testfiles/plist_files/lapl_32le b/test/testfiles/plist_files/lapl_32le
index 9d81759..eee238e 100644
--- a/test/testfiles/plist_files/lapl_32le
+++ b/test/testfiles/plist_files/lapl_32le
diff --git a/test/testfiles/plist_files/lapl_64be b/test/testfiles/plist_files/lapl_64be
index 9d81759..eee238e 100644
--- a/test/testfiles/plist_files/lapl_64be
+++ b/test/testfiles/plist_files/lapl_64be
diff --git a/test/testfiles/plist_files/lapl_64le b/test/testfiles/plist_files/lapl_64le
index 9d81759..eee238e 100644
--- a/test/testfiles/plist_files/lapl_64le
+++ b/test/testfiles/plist_files/lapl_64le
diff --git a/test/tfile.c b/test/tfile.c
index 8a8b889..5338c32 100644
--- a/test/tfile.c
+++ b/test/tfile.c
@@ -7141,6 +7141,132 @@ test_incr_filesize(void)
 
 /****************************************************************
 **
+**  test_min_dset_ohdr():
+**    Test API calls to toggle dataset object header minimization.
+**
+**  TODO (as separate function?):
+**    + setting persists between close and (re)open?
+**    + dataset header sizes created while changing value of toggle
+**
+****************************************************************/
+static void
+test_min_dset_ohdr(void)
+{
+    const char basename[]       = "min_dset_ohdr_testfile";
+    char filename[FILENAME_LEN] = "";
+    hid_t      file_id          = -1;
+    hid_t      file2_id         = -1;
+    hbool_t    minimize;
+    herr_t     ret;
+
+    MESSAGE(5, ("Testing dataset object header minimization\n"));
+
+    /*********/
+    /* SETUP */
+    /*********/
+
+    h5_fixname(basename, H5P_DEFAULT, filename, sizeof(filename));
+
+    file_id = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
+    CHECK_I(file_id, "H5Fcreate");
+
+    /*********/
+    /* TESTS */
+    /*********/
+
+    /*----------------------------------------
+     * TEST default value
+     */
+    ret = H5Fget_dset_no_attrs_hint(file_id, &minimize);
+    CHECK(ret, FAIL, "H5Fget_dset_no_attrs_hint");
+    VERIFY(minimize, FALSE, "minimize flag");
+
+    /*----------------------------------------
+     * TEST set to TRUE
+     */
+    ret = H5Fset_dset_no_attrs_hint(file_id, TRUE);
+    CHECK(ret, FAIL, "H5Fset_dset_no_attrs_hint");
+
+    ret = H5Fget_dset_no_attrs_hint(file_id, &minimize);
+    CHECK(ret, FAIL, "H5Fget_dset_no_attrs_hint");
+    VERIFY(minimize, TRUE, "minimize flag");
+
+    /*----------------------------------------
+     * TEST second file open on same filename
+     */
+    file2_id = H5Fopen(filename, H5F_ACC_RDWR, H5P_DEFAULT);
+    CHECK_I(file2_id, "H5Fopen");
+
+    /* verify TRUE setting on second open
+     */
+    ret = H5Fget_dset_no_attrs_hint(file_id, &minimize);
+    CHECK(ret, FAIL, "H5Fget_dset_no_attrs_hint");
+    VERIFY(minimize, TRUE, "minimize flag");
+
+    /* re-set to FALSE on first open
+     */
+    ret = H5Fset_dset_no_attrs_hint(file_id, FALSE);
+    CHECK(ret, FAIL, "H5Fset_dset_no_attrs_hint");
+
+    /* verify FALSE set on both opens
+     */
+    ret = H5Fget_dset_no_attrs_hint(file_id, &minimize);
+    CHECK(ret, FAIL, "H5Fget_dset_no_attrs_hint");
+    VERIFY(minimize, FALSE, "minimize flag");
+
+    ret = H5Fget_dset_no_attrs_hint(file2_id, &minimize);
+    CHECK(ret, FAIL, "H5Fget_dset_no_attrs_hint");
+    VERIFY(minimize, FALSE, "minimize flag");
+
+    /* re-set to TRUE on second open
+     */
+    ret = H5Fset_dset_no_attrs_hint(file2_id, TRUE);
+    CHECK(ret, FAIL, "H5Fset_dset_no_attrs_hint");
+
+    /* verify TRUE set on both opens
+     */
+    ret = H5Fget_dset_no_attrs_hint(file_id, &minimize);
+    CHECK(ret, FAIL, "H5Fget_dset_no_attrs_hint");
+    VERIFY(minimize, TRUE, "minimize flag");
+
+    ret = H5Fget_dset_no_attrs_hint(file2_id, &minimize);
+    CHECK(ret, FAIL, "H5Fget_dset_no_attrs_hint");
+    VERIFY(minimize, TRUE, "minimize flag");
+
+    /*----------------------------------------
+     * TEST error cases
+     */
+
+    /* trying to set with invalid file ID */
+    H5E_BEGIN_TRY {
+        ret = H5Fset_dset_no_attrs_hint(-1, TRUE);
+    } H5E_END_TRY;
+    VERIFY(ret, FAIL, "H5Fset_dset_no_attrs_hint");
+
+    /* trying to get with invalid file ID */
+    H5E_BEGIN_TRY {
+        ret = H5Fget_dset_no_attrs_hint(-1, &minimize);
+    } H5E_END_TRY;
+    VERIFY(ret, FAIL, "H5Fget_dset_no_attrs_hint");
+
+    /* trying to get with invalid pointer */
+    H5E_BEGIN_TRY {
+        ret = H5Fget_dset_no_attrs_hint(file_id, NULL);
+    } H5E_END_TRY;
+    VERIFY(ret, FAIL, "H5Fget_dset_no_attrs_hint");
+
+    /************/
+    /* TEARDOWN */
+    /************/
+
+    ret = H5Fclose(file_id);
+    CHECK(ret, FAIL, "H5Fclose");
+    ret = H5Fclose(file2_id);
+    CHECK(ret, FAIL, "H5Fclose");
+} /* end test_min_dset_ohdr() */
+
+/****************************************************************
+**
 **  test_deprec():
 **    Test deprecated functionality.
 **
@@ -7426,6 +7552,7 @@ test_file(void)
     test_libver_macros();                       /* Test the macros for library version comparison */
     test_libver_macros2();                      /* Test the macros for library version comparison */
     test_incr_filesize();                       /* Test H5Fincrement_filesize() and H5Fget_eoa() */
+    test_min_dset_ohdr();                       /* Test datset object header minimization */
 #ifndef H5_NO_DEPRECATED_SYMBOLS
     test_file_ishdf5();                         /* Test detecting HDF5 files correctly */
     test_deprec();                              /* Test deprecated routines */
diff --git a/test/tsohm.c b/test/tsohm.c
index 718b12f..bd73d00 100644
--- a/test/tsohm.c
+++ b/test/tsohm.c
@@ -13,7 +13,7 @@
 
 /***********************************************************
 *
-* Test program:	 tsohm
+* Test program: tsohm
 *
 * Test Shared Object Header Messages
 *
@@ -25,9 +25,9 @@
  * This file needs to access private information from the H5F package.
  * This file also needs to access the file testing code.
  */
-#define H5F_FRIEND		/*suppress error about including H5Fpkg	  */
+#define H5F_FRIEND   /* suppress error about including H5Fpkg      */
 #define H5F_TESTING
-#include "H5Fpkg.h"		/* File access	 			*/
+#include "H5Fpkg.h"  /* File access */
 
 /* Default SOHM values */
 #define DEF_NUM_INDEXES 0
@@ -178,40 +178,39 @@ static void test_sohm_extlink(void);
 
 /****************************************************************
 **
-**  check_fcpl_values(): Helper function for test_sohm_fcpl.
-**         Verifies that the *_in and *_out parameters are equal.
+**  verify_fcpl_values(): Verifies that FCPL is set as expected.
 **
 ****************************************************************/
-static void check_fcpl_values(hid_t fcpl_id, const unsigned nindexes_in,
-                const unsigned *flags_in, const unsigned *minsizes_in,
-                unsigned l2b, unsigned b2l)
+static void
+verify_fcpl_values(hid_t fcpl_id, const unsigned nindexes_expected, const unsigned *flags_expected, const unsigned *minsizes_expected, unsigned l2b, unsigned b2l)
 {
-    unsigned    num_indexes;
-    unsigned    index_flags, min_mesg_size;
-    unsigned    list_size, btree_size;
-    unsigned     x;
-    herr_t      ret;
-
-    /* Verify number of indexes is set to default */
-    ret = H5Pget_shared_mesg_nindexes(fcpl_id, &num_indexes);
+    unsigned  nindexes_actual;
+    unsigned  list_size;
+    unsigned  btree_size;
+    unsigned  x;
+    herr_t    ret;
+
+    /* Number of indexes */
+    ret = H5Pget_shared_mesg_nindexes(fcpl_id, &nindexes_actual);
     CHECK_I(ret, "H5Pget_shared_mesg_nindexes");
-    VERIFY(num_indexes, nindexes_in, "H5Pget_shared_mesg_nindexes");
+    VERIFY(nindexes_actual, nindexes_expected, "H5Pget_shared_mesg_nindexes");
 
-    /* Verify index flags and minsizes are set */
-    for(x=0; x<num_indexes; ++x)
-    {
-        ret = H5Pget_shared_mesg_index(fcpl_id, x, &index_flags, &min_mesg_size);
+    /* Index flags and minsizes */
+    for(x=0; x<nindexes_actual; ++x) {
+        unsigned flags_i;
+        unsigned min_mesg_size;
+        ret = H5Pget_shared_mesg_index(fcpl_id, x, &flags_i, &min_mesg_size);
         CHECK_I(ret, "H5Pget_shared_mesg_index");
-        VERIFY(index_flags, flags_in[x], "H5Pget_shared_mesg_index");
-        VERIFY(min_mesg_size, minsizes_in[x], "H5Pget_shared_mesg_index");
+        VERIFY(flags_i, flags_expected[x], "H5Pget_shared_mesg_index");
+        VERIFY(min_mesg_size, minsizes_expected[x], "H5Pget_shared_mesg_index");
     }
 
-    /* Check list-to-btree and btree-to-list values */
+    /* List-to-btree and btree-to-list values */
     ret = H5Pget_shared_mesg_phase_change(fcpl_id, &list_size, &btree_size);
     CHECK_I(ret, "H5Pset_shared_mesg_phase_change");
     VERIFY(list_size, l2b, "H5Pset_shared_mesg_phase_change");
     VERIFY(btree_size, b2l, "H5Pset_shared_mesg_phase_change");
-}
+} /* verify_fcpl_values */
 
 
 /****************************************************************
@@ -219,22 +218,21 @@ static void check_fcpl_values(hid_t fcpl_id, const unsigned nindexes_in,
 **  test_sohm_fcpl(): Test File Creation Property Lists.
 **
 ****************************************************************/
-static void test_sohm_fcpl(void)
+static void
+test_sohm_fcpl(void)
 {
-    hid_t       fid = -1;
-    hid_t       fcpl_id = -1;
-    hid_t       fcpl2_id = -1;
-    unsigned    x;
-    herr_t	ret;		/* Generic return value	*/
+    hid_t    fid = -1;
+    hid_t    fcpl_id = -1;
+    hid_t    fcpl2_id = -1;
+    unsigned x;
+    herr_t   ret;
 
-    /* Output message about test being performed */
     MESSAGE(5, ("Testing File Creation Properties for Shared Messages\n"));
 
     fcpl_id = H5Pcreate(H5P_FILE_CREATE);
     CHECK_I(fcpl_id, "H5Pcreate");
 
-    /* Verify fcpl values */
-    check_fcpl_values(fcpl_id, DEF_NUM_INDEXES, def_type_flags, def_minsizes, DEF_L2B, DEF_B2L);
+    verify_fcpl_values(fcpl_id, DEF_NUM_INDEXES, def_type_flags, def_minsizes, DEF_L2B, DEF_B2L);
 
     /* Create a file with this fcpl and make sure that all the values can be
      * retrieved.
@@ -245,8 +243,7 @@ static void test_sohm_fcpl(void)
     fcpl2_id = H5Fget_create_plist(fid);
     CHECK_I(fcpl2_id, "H5Fcreate");
 
-    /* Verify fcpl values */
-    check_fcpl_values(fcpl2_id, DEF_NUM_INDEXES, def_type_flags, def_minsizes, DEF_L2B, DEF_B2L);
+    verify_fcpl_values(fcpl2_id, DEF_NUM_INDEXES, def_type_flags, def_minsizes, DEF_L2B, DEF_B2L);
 
     ret = H5Pclose(fcpl2_id);
     CHECK_I(ret, "H5Pclose");
@@ -262,8 +259,7 @@ static void test_sohm_fcpl(void)
     fcpl2_id = H5Fget_create_plist(fid);
     CHECK_I(ret, "H5Fcreate");
 
-    /* Verify fcpl values */
-    check_fcpl_values(fcpl2_id, DEF_NUM_INDEXES, def_type_flags, def_minsizes, DEF_L2B, DEF_B2L);
+    verify_fcpl_values(fcpl2_id, DEF_NUM_INDEXES, def_type_flags, def_minsizes, DEF_L2B, DEF_B2L);
 
     /* Clean up */
     ret = H5Pclose(fcpl2_id);
@@ -289,7 +285,7 @@ static void test_sohm_fcpl(void)
     ret = H5Pset_shared_mesg_phase_change(fcpl_id, TEST_L2B, TEST_B2L);
     CHECK_I(ret, "H5Pset_shared_mesg_phase_change");
 
-    check_fcpl_values(fcpl_id, TEST_NUM_INDEXES, test_type_flags, test_minsizes, TEST_L2B, TEST_B2L);
+    verify_fcpl_values(fcpl_id, TEST_NUM_INDEXES, test_type_flags, test_minsizes, TEST_L2B, TEST_B2L);
 
     /* Use the fcpl to create a file and get it back again */
     fid = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl_id, H5P_DEFAULT);
@@ -297,8 +293,7 @@ static void test_sohm_fcpl(void)
     fcpl2_id = H5Fget_create_plist(fid);
     CHECK_I(fcpl2_id, "H5Fcreate");
 
-    /* Verify fcpl values */
-    check_fcpl_values(fcpl2_id, TEST_NUM_INDEXES, test_type_flags, test_minsizes, TEST_L2B, TEST_B2L);
+    verify_fcpl_values(fcpl2_id, TEST_NUM_INDEXES, test_type_flags, test_minsizes, TEST_L2B, TEST_B2L);
 
     ret = H5Pclose(fcpl2_id);
     CHECK_I(ret, "H5Pclose");
@@ -314,8 +309,7 @@ static void test_sohm_fcpl(void)
     fcpl2_id = H5Fget_create_plist(fid);
     CHECK_I(ret, "H5Fcreate");
 
-    /* Verify fcpl values */
-    check_fcpl_values(fcpl2_id, TEST_NUM_INDEXES, test_type_flags, test_minsizes, TEST_L2B, TEST_B2L);
+    verify_fcpl_values(fcpl2_id, TEST_NUM_INDEXES, test_type_flags, test_minsizes, TEST_L2B, TEST_B2L);
 
     /* Clean up */
     ret = H5Pclose(fcpl2_id);
@@ -323,7 +317,70 @@ static void test_sohm_fcpl(void)
     ret = H5Fclose(fid);
     CHECK_I(ret, "H5Fclose");
 
-    /* Test giving bogus values to H5P* functions */
+    /* Actually, the list max can be exactly 1 greater than the
+     * btree min, but no more.
+     * Reset the second index.
+     */
+    ret = H5Pset_shared_mesg_index(fcpl_id, 1, test_type_flags[1], 15);
+    CHECK_I(ret, "H5Pset_shared_mesg_index");
+    ret = H5Pset_shared_mesg_phase_change(fcpl_id, 10, 11);
+    CHECK_I(ret, "H5Pset_shared_mesg_phase_change");
+    fid = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl_id, H5P_DEFAULT);
+    CHECK_I(fid, "H5Fcreate");
+    ret = H5Fclose(fid);
+    CHECK_I(ret, "H5Fclose");
+
+    /* Test edge cases:
+     * H5O_SHMESG_MAX_NINDEXES and H5O_SHMESG_MAX_LIST_SIZE should be valid
+     * values.
+     * Creating a file with uninitialized indexes should work. (TODO: not implemented?)
+     */
+    ret = H5Pset_shared_mesg_nindexes(fcpl_id, H5O_SHMESG_MAX_NINDEXES);
+    CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
+    ret = H5Pset_shared_mesg_phase_change(fcpl_id, H5O_SHMESG_MAX_LIST_SIZE, H5O_SHMESG_MAX_LIST_SIZE);
+    CHECK_I(ret, "H5Pset_shared_mesg_phase_change");
+    fid = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl_id, H5P_DEFAULT);
+    CHECK_I(fid, "H5Fcreate");
+
+    /* Clean up */
+    ret = H5Pclose(fcpl_id);
+    CHECK_I(ret, "H5Pclose");
+    ret = H5Fclose(fid);
+    CHECK_I(ret, "H5Fclose");
+} /* test_sohm_fcpl */
+
+
+/****************************************************************
+**
+**  test_sohm_fcpl_errors(): Test bogus FCPL settings for SOHMs
+**
+****************************************************************/
+static void
+test_sohm_fcpl_errors(void)
+{
+    hid_t    fcpl_id = -1;
+    hid_t    fid     = -1;
+    unsigned x;
+    herr_t   ret;
+
+    MESSAGE(5, ("Testing bogus file creation properties for shared messages\n"));
+
+    fcpl_id = H5Pcreate(H5P_FILE_CREATE);
+    CHECK_I(fcpl_id, "H5Pcreate");
+
+    /* Set up index values */
+    ret = H5Pset_shared_mesg_nindexes(fcpl_id, TEST_NUM_INDEXES);
+    CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
+    for(x = 0; x < TEST_NUM_INDEXES; ++x) {
+        ret = H5Pset_shared_mesg_index(fcpl_id, x, test_type_flags[x], test_minsizes[x]);
+        CHECK_I(ret, "H5Pset_shared_mesg_index");
+    }
+
+    ret = H5Pset_shared_mesg_phase_change(fcpl_id, TEST_L2B, TEST_B2L);
+    CHECK_I(ret, "H5Pset_shared_mesg_phase_change");
+
+    verify_fcpl_values(fcpl_id, TEST_NUM_INDEXES, test_type_flags, test_minsizes, TEST_L2B, TEST_B2L);
+
     H5E_BEGIN_TRY {
         /* Trying to create too many indexes should fail */
         ret = H5Pset_shared_mesg_nindexes(fcpl_id, H5O_SHMESG_MAX_NINDEXES + 1);
@@ -370,40 +427,7 @@ static void test_sohm_fcpl(void)
         ret = H5Pset_shared_mesg_phase_change(fcpl_id, H5O_SHMESG_MAX_LIST_SIZE, H5O_SHMESG_MAX_LIST_SIZE+1);
         VERIFY(ret, -1, "H5Pset_shared_mesg_phase_change");
     } H5E_END_TRY
-
-
-    /* Actually, the list max can be exactly 1 greater than the
-     * btree min, but no more.  Also, the errors above shouldn't
-     * have corrupted the fcpl, although we do need to reset the
-     * second index that we changed above.
-     */
-    ret = H5Pset_shared_mesg_index(fcpl_id, 1, test_type_flags[1], 15);
-    CHECK_I(ret, "H5Pset_shared_mesg_index");
-    ret = H5Pset_shared_mesg_phase_change(fcpl_id, 10, 11);
-    CHECK_I(ret, "H5Pset_shared_mesg_phase_change");
-    fid = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl_id, H5P_DEFAULT);
-    CHECK_I(fid, "H5Fcreate");
-    ret = H5Fclose(fid);
-    CHECK_I(ret, "H5Fclose");
-
-    /* Test edge cases; H5O_SHMESG_MAX_NINDEXES and H5O_SHMESG_MAX_LIST_SIZE should be
-     * valid values.  Also, creating a file with uninitialized indexes
-     * (indexes 3-5) should work.
-     */
-    ret = H5Pset_shared_mesg_nindexes(fcpl_id, H5O_SHMESG_MAX_NINDEXES);
-    CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
-    ret = H5Pset_shared_mesg_phase_change(fcpl_id, H5O_SHMESG_MAX_LIST_SIZE, H5O_SHMESG_MAX_LIST_SIZE);
-    CHECK_I(ret, "H5Pset_shared_mesg_phase_change");
-    fid = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl_id, H5P_DEFAULT);
-    CHECK_I(fid, "H5Fcreate");
-
-
-    /* Clean up */
-    ret = H5Pclose(fcpl_id);
-    CHECK_I(ret, "H5Pclose");
-    ret = H5Fclose(fid);
-    CHECK_I(ret, "H5Fclose");
-}
+} /* test_sohm_fcpl_errors */
 
 
 /*-------------------------------------------------------------------------
@@ -455,7 +479,8 @@ error:
       H5Tclose(dtype1_id);
     } H5E_END_TRY
     return -1;
-}
+} /* make_dtype1 */
+
 
 /*-------------------------------------------------------------------------
  * Function:    make_dtype_2
@@ -518,9 +543,9 @@ error:
       H5Tclose(int_id);
     } H5E_END_TRY
     return -1;
-}
-
+} /* make_dtype2 */
 
+
 /*-------------------------------------------------------------------------
  * Function:    close_reopen_file
  *
@@ -540,16 +565,16 @@ error:
 static hid_t
 close_reopen_file(hid_t file, const char* filename, hid_t fapl_id)
 {
-    hid_t fid;
-
-    if(H5Fclose(file) < 0) FAIL_STACK_ERROR
-    if((fid = H5Fopen(filename, H5F_ACC_RDWR, fapl_id)) < 0) FAIL_STACK_ERROR
-
-    return(fid);
+    if (H5Fclose(file) < 0)
+        FAIL_STACK_ERROR
+    file = H5Fopen(filename, H5F_ACC_RDWR, fapl_id);
+    if (file < 0)
+        FAIL_STACK_ERROR
+    return(file);
 
 error:
     return -1;
-}
+} /* close_reopen_file */
 
 
 /*-------------------------------------------------------------------------
@@ -557,7 +582,6 @@ error:
  *
  * Purpose:     Creates object headers that use a large datatype message.
  *
- *              Used in test_sohm_basic.  Should close the file ID passed in.
  *              Set test_file_closing to 1 to add file closing and reopening
  *              whenever possible (to test that SOHMs are written correctly
  *              on disk and not just in memory).
@@ -571,7 +595,7 @@ error:
  *-------------------------------------------------------------------------
  */
 static hid_t
-size1_helper(hid_t file, const char* filename, hid_t fapl_id, int test_file_closing)
+size1_helper(hid_t file, const char *filename, hid_t fapl_id, int test_file_closing)
 {
     dtype1_struct wdata;
     dtype1_struct rdata;
@@ -581,6 +605,32 @@ size1_helper(hid_t file, const char* filename, hid_t fapl_id, int test_file_clos
     hsize_t     dim1[1];
     int         x;
 
+/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+ * Macro:      TSOHM_S1H_VERIFY_DATA
+ *
+ * Purpose:    Encapsulate a common pattern:
+ *             Reads the dataset and verifies that [a subset of] the data
+ *             are as expected.
+ *
+ * Programmer: Jacob Smith
+ *             2018 November 1
+ * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+ */
+#define TSOHM_S1H_VERIFY_DATA(dset_id, dtype_id) \
+{                                                \
+    HDmemset(&rdata, 0, sizeof(rdata));          \
+    if (0 > H5Dread((dset_id), (dtype_id), H5S_ALL, H5S_ALL, H5P_DEFAULT, &rdata)) { \
+        H5_FAILED(); AT();                       \
+        printf("Can't read data\n");             \
+        goto error;                              \
+    }                                            \
+    if ((rdata.i1 != wdata.i1) || (rdata.i2 != wdata.i2) || HDstrcmp(rdata.str, wdata.str)) { \
+        H5_FAILED(); AT();                       \
+        printf("incorrect read data\n");         \
+        goto error;                              \
+    }                                            \
+} /* TSOHM_S1H_VERIFY_DATA() definition */
+
     /* Closing and re-opening the file takes a long time on systems without
      * local disks.  Don't close and reopen if express testing is enabled.
      */
@@ -603,107 +653,68 @@ size1_helper(hid_t file, const char* filename, hid_t fapl_id, int test_file_clos
     /* Intialize rdata */
     HDmemset(&rdata, 0, sizeof(rdata));
 
-    if((dtype1_id = make_dtype_1()) < 0) TEST_ERROR
+    dtype1_id = make_dtype_1();
+    if(dtype1_id < 0) TEST_ERROR
 
-    /* Create the dataspace and dataset */
     dim1[0] = 1;
-    if((space_id = H5Screate_simple(1, dim1, NULL)) < 0) TEST_ERROR
+    space_id = H5Screate_simple(1, dim1, NULL);
+    if(space_id < 0) TEST_ERROR
 
-    if((dset_id = H5Dcreate2(file, DSETNAME[0], dtype1_id, space_id, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) FAIL_STACK_ERROR
+    dset_id = H5Dcreate2(file, DSETNAME[0], dtype1_id, space_id, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+    if(dset_id < 0) FAIL_STACK_ERROR
 
     /* Test writing and reading */
     if(H5Dwrite(dset_id, dtype1_id, H5S_ALL, H5S_ALL, H5P_DEFAULT, &wdata) < 0) FAIL_STACK_ERROR
-
-    if(H5Dread(dset_id, dtype1_id, H5S_ALL, H5S_ALL, H5P_DEFAULT, &rdata) < 0) FAIL_STACK_ERROR
-
-    if(rdata.i1 != wdata.i1 || rdata.i2 != wdata.i2 || HDstrcmp(rdata.str, wdata.str)) {
-        H5_FAILED(); AT();
-        printf("incorrect read data\n");
-        goto error;
-    } /* end if */
+    TSOHM_S1H_VERIFY_DATA(dset_id, dtype1_id)
     if(H5Dclose(dset_id) < 0) FAIL_STACK_ERROR
 
-    /* Close and re-open the file if requested*/
     if(test_file_closing)
         if((file = close_reopen_file(file, filename, fapl_id)) < 0) TEST_ERROR
 
-    /* Create more datasets with the same datatype */
-    if((dset_id = H5Dcreate2(file, DSETNAME[1], dtype1_id, space_id, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) FAIL_STACK_ERROR
-    if(H5Dclose(dset_id) < 0) FAIL_STACK_ERROR
+    /* Create 3 more datasets with the same datatype/dataspace */
+    for (x = 1; x < 4; x++) {
+        dset_id = H5Dcreate2(file, DSETNAME[x], dtype1_id, space_id, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+        if (0 > dset_id) FAIL_STACK_ERROR
+        if (x == 3)
+            if(H5Dwrite(dset_id, dtype1_id, H5S_ALL, H5S_ALL, H5P_DEFAULT, &wdata) < 0) TEST_ERROR
+        if (H5Dclose(dset_id) < 0) FAIL_STACK_ERROR
 
-    /* Close and re-open the file if requested*/
-    if(test_file_closing)
-        if((file = close_reopen_file(file, filename, fapl_id)) < 0) TEST_ERROR
-
-    if((dset_id = H5Dcreate2(file, DSETNAME[2], dtype1_id, space_id, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
-    if(H5Dclose(dset_id) < 0) TEST_ERROR
-
-    /* Close and re-open the file if requested*/
-    if(test_file_closing)
-        if((file = close_reopen_file(file, filename, fapl_id)) < 0) TEST_ERROR
-
-    if((dset_id = H5Dcreate2(file,DSETNAME[3],dtype1_id,space_id,H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
-
-    /* Write data to dataset 3 for later */
-    if(H5Dwrite(dset_id, dtype1_id, H5S_ALL, H5S_ALL, H5P_DEFAULT, &wdata) < 0) TEST_ERROR
+        if (test_file_closing)
+            if((file = close_reopen_file(file, filename, fapl_id)) < 0) TEST_ERROR
+    }
 
-    if(H5Dclose(dset_id) < 0) TEST_ERROR
     if(H5Tclose(dtype1_id) < 0) TEST_ERROR
 
-    /* Close and re-open the file if requested*/
-    if(test_file_closing)
-        if((file = close_reopen_file(file, filename, fapl_id)) < 0) TEST_ERROR
-
     /* Make sure the data has been written successfully */
-    if((dset_id = H5Dopen2(file, DSETNAME[0], H5P_DEFAULT)) < 0) TEST_ERROR
-    if((dtype1_id = H5Dget_type(dset_id)) < 0) TEST_ERROR
-
-    /* Read data back again */
-    HDmemset(&rdata, 0, sizeof(rdata));
-    if(H5Dread(dset_id, dtype1_id, H5S_ALL, H5S_ALL, H5P_DEFAULT, &rdata) < 0) {
-        H5_FAILED(); AT();
-        printf("Can't read data\n");
-        goto error;
-    } /* end if */
-
-    if(rdata.i1 != wdata.i1 || rdata.i2 != wdata.i2 || HDstrcmp(rdata.str, wdata.str)) {
-        H5_FAILED(); AT();
-        printf("incorrect read data\n");
-        goto error;
-    } /* end if */
+    dset_id = H5Dopen2(file, DSETNAME[0], H5P_DEFAULT);
+    if(dset_id < 0) TEST_ERROR
+    dtype1_id = H5Dget_type(dset_id);
+    if(dtype1_id < 0) TEST_ERROR
+    TSOHM_S1H_VERIFY_DATA(dset_id, dtype1_id)
 
     if(H5Dclose(dset_id) < 0) TEST_ERROR
 
-    /* Create several copies of the dataset (this increases the amount of space saved by sharing the datatype message) */
+    /* Create several copies of the dataset
+     * this increases the amount of space saved by sharing the datatype message
+     */
     for(x = 0; x < SOHM_HELPER_NUM_EX_DSETS; x++) {
-        if((dset_id = H5Dcreate2(file, EXTRA_DSETNAME[x], dtype1_id, space_id, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
+        dset_id = H5Dcreate2(file, EXTRA_DSETNAME[x], dtype1_id, space_id, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+        if(dset_id < 0) TEST_ERROR
         if(H5Dclose(dset_id) < 0) TEST_ERROR
 
-        /* Close and re-open the file if requested*/
         if(test_file_closing)
             if((file = close_reopen_file(file, filename, fapl_id)) < 0) TEST_ERROR
-    } /* end for */
+    }
 
     if(H5Tclose(dtype1_id) < 0) TEST_ERROR
     if(H5Sclose(space_id) < 0) TEST_ERROR
 
     /* Ensure that we can still read data back from dataset 3 */
-    if((dset_id = H5Dopen2(file, DSETNAME[3], H5P_DEFAULT)) < 0) TEST_ERROR
-    if((dtype1_id = H5Dget_type(dset_id)) < 0) TEST_ERROR
-
-    /* Read data back again */
-    HDmemset(&rdata, 0, sizeof(rdata));
-    if(H5Dread(dset_id, dtype1_id, H5S_ALL, H5S_ALL, H5P_DEFAULT, &rdata) < 0) {
-        H5_FAILED(); AT();
-        printf("Can't read data\n");
-        goto error;
-    } /* end if */
-
-    if(rdata.i1 != wdata.i1 || rdata.i2 != wdata.i2 || HDstrcmp(rdata.str, wdata.str)) {
-        H5_FAILED(); AT();
-        printf("incorrect read data\n");
-        goto error;
-    } /* end if */
+    dset_id = H5Dopen2(file, DSETNAME[3], H5P_DEFAULT);
+    if(dset_id < 0) TEST_ERROR
+    dtype1_id = H5Dget_type(dset_id);
+    if(dtype1_id < 0) TEST_ERROR
+    TSOHM_S1H_VERIFY_DATA(dset_id, dtype1_id)
 
     if(H5Dclose(dset_id) < 0) TEST_ERROR
     if(H5Tclose(dtype1_id) < 0) TEST_ERROR
@@ -717,7 +728,42 @@ size1_helper(hid_t file, const char* filename, hid_t fapl_id, int test_file_clos
         H5Fclose(file);
     } H5E_END_TRY
     return -1;
-}
+#undef TSOHM_S1H_VERIFY_DATA /* macro is exclusive to this function */
+} /* size1_helper */
+
+
+/*----------------------------------------------------------------------------
+ * Function: getsize_testsize1
+ *
+ * Purpose: Creates a test file, populates it, and returns its file size.
+ *          Oject header information from the "first" dataset in the file
+ *          is stored in pointer `oinfo`.
+ *
+ * Programmer: Jacob Smith
+ *             2018 November 1
+ *----------------------------------------------------------------------------
+ */
+static h5_stat_size_t
+getsize_testsize1(const char *filename, hid_t fcpl_id, hid_t fapl_id, unsigned open_close, H5O_info_t *oinfo)
+{
+    hid_t file = -1;
+    herr_t ret;
+
+    file = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl_id, fapl_id);
+    CHECK_I(file, "H5Fcreate");
+
+    file = size1_helper(file, FILENAME, fapl_id, open_close);
+    CHECK_I(file, "size1_helper");
+
+    ret = H5Oget_info_by_name2(file, DSETNAME[0], oinfo, H5O_INFO_HDR, H5P_DEFAULT);
+    CHECK_I(ret, "H5Oget_info_by_name");
+
+    ret = H5Fclose(file);
+    CHECK_I(ret, "H5Fclose");
+
+    return h5_get_file_size(FILENAME, fapl_id);
+} /* getsize_testsize1 */
+
 
 /*-------------------------------------------------------------------------
  * Function:    test_sohm_size1
@@ -727,17 +773,26 @@ size1_helper(hid_t file, const char* filename, hid_t fapl_id, int test_file_clos
  * Programmer:  James Laird
  *              Monday, April 10, 2006
  *
- * Modifications:
- *
  *-------------------------------------------------------------------------
  */
-static void test_sohm_size1(void)
+static void
+test_sohm_size1(void)
 {
     hid_t       file = -1;
     hid_t       fcpl_id = -1;
     hid_t       fapl_id = -1;
-    hsize_t     sohm_oh_size;
-    hsize_t     sohm_btree_oh_size;
+
+    unsigned       use_shared = 0;
+    unsigned       use_btree = 0;
+    unsigned       open_close = 0;
+    h5_stat_size_t file_sizes[9];
+    unsigned       size_index = 0;
+    hsize_t        oh_sizes[3];
+    unsigned       oh_size_index = 0;
+
+    hsize_t        norm_oh_size;
+    hsize_t        sohm_oh_size;
+    hsize_t        sohm_btree_oh_size;
     h5_stat_size_t norm_empty_filesize;
     h5_stat_size_t sohm_empty_filesize;
     h5_stat_size_t sohm_btree_empty_filesize;
@@ -747,6 +802,7 @@ static void test_sohm_size1(void)
     h5_stat_size_t norm_final_filesize2;
     h5_stat_size_t sohm_final_filesize2;
     h5_stat_size_t sohm_btree_final_filesize2;
+
     H5O_info_t  oinfo;
     unsigned    num_indexes = 1;
     unsigned    index_flags = H5O_SHMESG_DTYPE_FLAG;
@@ -757,177 +813,103 @@ static void test_sohm_size1(void)
 
     MESSAGE(5, ("Testing that shared datatypes save space\n"));
 
-
     /* Create a FAPL with "semi" close degree, to detect dangling IDs */
     fapl_id = H5Pcreate(H5P_FILE_ACCESS);
     CHECK_I(fapl_id, "H5Pcreate");
-
     ret = H5Pset_fclose_degree(fapl_id, H5F_CLOSE_SEMI);
     CHECK_I(ret, "H5Pset_fclose_degree");
 
-    /* Create a file with SOHMs disabled and get its size */
-    fcpl_id = H5Pcreate(H5P_FILE_CREATE);
-    CHECK_I(fcpl_id, "H5Pcreate");
-
-    ret = H5Pset_shared_mesg_nindexes(fcpl_id, 0);
-    CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
-
-    file = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl_id, fapl_id);
-    CHECK_I(file, "H5Fcreate");
-
-    ret = H5Fclose(file);
-    CHECK_I(ret, "H5Fclose");
-
-    /* Get the file size */
-    norm_empty_filesize = h5_get_file_size(FILENAME, fapl_id);
-
-    /* Add a bunch of large datatypes to the file */
-    file = H5Fopen(FILENAME, H5F_ACC_RDWR, fapl_id);
-    CHECK_I(file, "H5Fopen");
-    file = size1_helper(file, FILENAME, fapl_id, 0);
-    CHECK_I(file, "size1_helper");
-    ret = H5Fclose(file);
-    CHECK_I(ret, "H5Fclose");
-
-    /* Get the new file size */
-    norm_final_filesize = h5_get_file_size(FILENAME, fapl_id);
-
-    /* Use the same property list to create a new file. */
-    file = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl_id, fapl_id);
-    CHECK_I(file, "H5Fcreate");
-
-    ret = H5Pclose(fcpl_id);
-    CHECK_I(ret, "H5Pclose");
-
-    /* Add the same large datatypes, but keep closing and re-opening the file */
-    file = size1_helper(file, FILENAME, fapl_id, 1);
-    CHECK_I(file, "size1_helper");
-    ret = H5Fclose(file);
-    CHECK_I(ret, "H5Fclose");
-
-    /* Get the file size */
-    norm_final_filesize2 = h5_get_file_size(FILENAME, fapl_id);
-
-
-
-    /* Now do the same thing for a file with SOHMs enabled */
-    /* Create FCPL with SOHMs enabled */
-    fcpl_id = H5Pcreate(H5P_FILE_CREATE);
-    CHECK_I(fcpl_id, "H5Pcreate");
-
-    /* Tests one index holding only datatype messages */
-    ret = H5Pset_shared_mesg_nindexes(fcpl_id, num_indexes);
-    CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
-    ret = H5Pset_shared_mesg_index(fcpl_id, 0, index_flags, min_mesg_size);
-    CHECK_I(ret, "H5Pset_shared_mesg_index");
-    ret = H5Pset_shared_mesg_phase_change(fcpl_id, list_max, btree_min);
-    CHECK_I(ret, "H5Pset_shared_mesg_phase_change");
-
-    /* Create a file */
-    file = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl_id, fapl_id);
-    CHECK_I(file, "H5Fcreate");
-
-    ret = H5Fclose(file);
-    CHECK_I(ret, "H5Fclose");
-
-    sohm_empty_filesize = h5_get_file_size(FILENAME, fapl_id);
-
-    /* Add a bunch of datatypes to this file */
-    file = H5Fopen(FILENAME, H5F_ACC_RDWR, fapl_id);
-    CHECK_I(file, "H5Fopen");
-    file = size1_helper(file, FILENAME, fapl_id, 0);
-    CHECK_I(file, "size1_helper");
+    /* ----------------------------------------
+     * Run operations, accumulating file sizes to compare later.
+     */
+
+    for (use_shared = 0; use_shared < 2; use_shared++) {
+        for (use_btree = 0; use_btree < 2; use_btree++) {
+
+            /* cannot use btree indexing without shared messages; skip case */
+            if (use_btree && !use_shared)
+                continue;
+
+            fcpl_id = H5Pcreate(H5P_FILE_CREATE);
+            CHECK_I(fcpl_id, "H5Pcreate");
+
+            if (use_shared) {
+                /* Tests one index holding only datatype messages */
+                ret = H5Pset_shared_mesg_nindexes(fcpl_id, num_indexes);
+                CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
+                ret = H5Pset_shared_mesg_index(fcpl_id, 0, index_flags, min_mesg_size);
+                CHECK_I(ret, "H5Pset_shared_mesg_index");
+
+                if (use_btree) {
+                    ret = H5Pset_shared_mesg_phase_change(fcpl_id, 0, 0);
+                } else {
+                    ret = H5Pset_shared_mesg_phase_change(fcpl_id, list_max, btree_min);
+                }
+                CHECK_I(ret, "H5Pset_shared_mesg_phase_change");
+            } else {
+                ret = H5Pset_shared_mesg_nindexes(fcpl_id, 0);
+                CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
+            }
+
+            file = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl_id, fapl_id);
+            CHECK_I(file, "H5Fcreate");
+            ret = H5Fclose(file);
+            CHECK_I(ret, "H5Fclose");
 
-    /* Get the size of a dataset object header */
-    ret = H5Oget_info_by_name2(file, DSETNAME[0], &oinfo, H5O_INFO_HDR, H5P_DEFAULT);
-    CHECK_I(ret, "H5Oget_info_by_name");
-    ret = H5Fclose(file);
-    CHECK_I(ret, "H5Fclose");
-    sohm_oh_size = oinfo.hdr.space.total;
+            /* size of empty file */
+            file_sizes[size_index++] = h5_get_file_size(FILENAME, fapl_id);
 
-    /* Get the new file size */
-    sohm_final_filesize = h5_get_file_size(FILENAME, fapl_id);
+            /* size of populated file, with different populating behaviors */
+            for (open_close = 0; open_close < 2; open_close++)
+                file_sizes[size_index++] = getsize_testsize1(FILENAME, fcpl_id, fapl_id, open_close, &oinfo);
+            oh_sizes[oh_size_index++] = oinfo.hdr.space.total;
 
-    /* Use the same property list to create a new file. */
-    file = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl_id, fapl_id);
-    CHECK_I(file, "H5Fcreate");
+            ret = H5Pclose(fcpl_id);
+            CHECK_I(ret, "H5Pclose");
+        } /* for btree/listed messages */
+    } /* for normal/shared messages */
 
-    ret = H5Pclose(fcpl_id);
+    ret = H5Pclose(fapl_id);
     CHECK_I(ret, "H5Pclose");
 
-    /* Add the same large datatypes, but keep closing and re-opening the file */
-    file = size1_helper(file, FILENAME, fapl_id, 1);
-    CHECK_I(file, "size1_helper");
-    ret = H5Fclose(file);
-    CHECK_I(ret, "H5Fclose");
-
-    /* Get the file size */
-    sohm_final_filesize2 = h5_get_file_size(FILENAME, fapl_id);
-
-
-
-    /* Create FCPL with SOHMs enabled that uses a B-tree index */
-    fcpl_id = H5Pcreate(H5P_FILE_CREATE);
-    CHECK_I(fcpl_id, "H5Pcreate");
-
-    /* Tests one index holding only datatype messages */
-    ret = H5Pset_shared_mesg_nindexes(fcpl_id, num_indexes);
-    CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
-    ret = H5Pset_shared_mesg_index(fcpl_id, 0, index_flags, min_mesg_size);
-    CHECK_I(ret, "H5Pset_shared_mesg_index");
-    ret = H5Pset_shared_mesg_phase_change(fcpl_id, 0, 0);
-    CHECK_I(ret, "H5Pset_shared_mesg_phase_change");
-
-    /* Create a file */
-    file = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl_id, fapl_id);
-    CHECK_I(file, "H5Fcreate");
-
-    ret = H5Fclose(file);
-    CHECK_I(ret, "H5Fclose");
+    /* sanity-check state of arrays */
+    VERIFY(9, size_index, "size_index");
+    VERIFY(3, oh_size_index, "oh_size_index");
 
-    sohm_btree_empty_filesize = h5_get_file_size(FILENAME, fapl_id);
-
-    /* Add a bunch of datatypes to this file */
-    file = H5Fopen(FILENAME, H5F_ACC_RDWR, fapl_id);
-    CHECK_I(file, "H5Fopen");
-    file = size1_helper(file, FILENAME, fapl_id, 0);
-    CHECK_I(file, "size1_helper");
-
-    /* Get the size of a dataset object header */
-    ret = H5Oget_info_by_name2(file, DSETNAME[0], &oinfo, H5O_INFO_HDR, H5P_DEFAULT);
-    CHECK_I(ret, "H5Oget_info_by_name");
-    ret = H5Fclose(file);
-    CHECK_I(ret, "H5Fclose");
-    sohm_btree_oh_size = oinfo.hdr.space.total;
-
-    /* Get the new file size */
-    sohm_btree_final_filesize = h5_get_file_size(FILENAME, fapl_id);
-
-    /* Use the same property list to create a new file. */
-    file = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl_id, fapl_id);
-    CHECK_I(file, "H5Fcreate");
-
-    ret = H5Pclose(fcpl_id);
-    CHECK_I(ret, "H5Pclose");
+    /* ----------------------------------------
+     * Check that all sizes make sense.
+     */
 
-    /* Add the same large datatypes, but keep closing and re-opening the file */
-    file = size1_helper(file, FILENAME, fapl_id, 1);
-    CHECK_I(file, "size1_helper");
-    ret = H5Fclose(file);
-    CHECK_I(ret, "H5Fclose");
+    /* Put result sizes into human-readable symbolic names.
+     * Order dependent on loop execution above.
+     */
+    norm_empty_filesize = file_sizes[0];
+    norm_final_filesize = file_sizes[1];
+    norm_final_filesize2 = file_sizes[2];
+    norm_oh_size = oh_sizes[0];
 
-    /* Get the file size */
-    sohm_btree_final_filesize2 = h5_get_file_size(FILENAME, fapl_id);
+    sohm_empty_filesize = file_sizes[3];
+    sohm_final_filesize = file_sizes[4];
+    sohm_final_filesize2 = file_sizes[5];
+    sohm_oh_size = oh_sizes[1];
 
+    sohm_btree_empty_filesize = file_sizes[6];
+    sohm_btree_final_filesize = file_sizes[7];
+    sohm_btree_final_filesize2 = file_sizes[8];
+    sohm_btree_oh_size = oh_sizes[2];
 
+    /* How the SOHM messages are stored shouldn't affect the
+     * size of the object header.
+     */
+    VERIFY(sohm_btree_oh_size, sohm_oh_size, "H5Oget_info_by_name");
 
-    /* Check that all sizes make sense */
+#if 0 /* TBD: lying comment or bug. See Jira HDFFV-10646 */
     /* Object headers in SOHM files should be smaller than normal object
-     * headers.  How the SOHM messages are stored shouldn't affect the
-     * size of the object header.
+     * headers.
      */
-    if(sohm_oh_size != sohm_btree_oh_size)
-        VERIFY(sohm_btree_oh_size, 1, "H5Oget_info_by_name");
+    if (sohm_oh_size >= norm_oh_size)
+        VERIFY(norm_oh_size, 1, "H5Oget_info_by_name");
+#endif /* Jira HDFFV-10646 */
 
     /* Both sohm files should be bigger than a normal file when empty.
      * It's hard to say whether a B-tree with no nodes allocated should be
@@ -942,23 +924,127 @@ static void test_sohm_size1(void)
         VERIFY(sohm_btree_empty_filesize, 1, "h5_get_file_size");
 
     /* When full, the sohm btree file should be smaller than the normal file.
-     * The sohm list file should be at least as small, since it doesn't need the
-     * overhead of a B-tree.
+     * The sohm list file should be at least as small, since it doesn't need
+     * the overhead of a B-tree.
      */
     if(sohm_btree_final_filesize >= norm_final_filesize)
         VERIFY(sohm_btree_final_filesize, 1, "h5_get_file_size");
     if(sohm_final_filesize > sohm_btree_final_filesize)
         VERIFY(sohm_final_filesize, 1, "h5_get_file_size");
 
-    /* This shouldn't change even if we open and close the file */
+    /* Comparative sizes shouldn't change even if we open and close the file
+     */
     if(sohm_btree_final_filesize2 >= norm_final_filesize2)
         VERIFY(sohm_btree_final_filesize2, 1, "h5_get_file_size");
     if(sohm_final_filesize2 > sohm_btree_final_filesize2)
         VERIFY(sohm_final_filesize2, 1, "h5_get_file_size");
 
+} /* test_sohm_size1 */
+
+
+/*---------------------------------------------------------------------------
+ * Function:    test_sohm_size_consistency_open_create
+ *
+ * Purpose:     Tests that header size is different depending on file open
+ *              procedure?
+ *              Uses "size1_helper" for file setup directed to a specific
+ *              file handle.
+ *
+ * Programmer:  Jacob Smith
+ *              2018 November 1
+ *
+ *---------------------------------------------------------------------------
+ */
+static void
+test_sohm_size_consistency_open_create(void)
+{
+    hid_t       file = -1;
+    hid_t       fcpl_id = -1;
+    hid_t       fapl_id = -1;
+    unsigned    use_btree;
+    hsize_t     oh_size_open;
+    hsize_t     oh_size_create;
+    H5O_info_t  oinfo;
+    unsigned    num_indexes = 1;
+    unsigned    index_flags = H5O_SHMESG_DTYPE_FLAG;
+    unsigned    min_mesg_size = 50;
+    unsigned    list_max = 11;
+    unsigned    btree_min = 10;
+    herr_t      ret;
+
+    MESSAGE(5, \
+    ("Testing that header size is consistent between H5Fopen and H5Fcreate\n"));
+
+    /* Create a FAPL with "semi" close degree, to detect dangling IDs */
+    fapl_id = H5Pcreate(H5P_FILE_ACCESS);
+    CHECK_I(fapl_id, "H5Pcreate");
+    ret = H5Pset_fclose_degree(fapl_id, H5F_CLOSE_SEMI);
+    CHECK_I(ret, "H5Pset_fclose_degree");
+
+    for (use_btree = 0; use_btree < 2; use_btree++) {
+        /* Create FCPL with SOHMs enabled
+         */
+        fcpl_id = H5Pcreate(H5P_FILE_CREATE);
+        CHECK_I(fcpl_id, "H5Pcreate");
+        ret = H5Pset_shared_mesg_nindexes(fcpl_id, num_indexes);
+        CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
+        ret = H5Pset_shared_mesg_index(fcpl_id, 0, index_flags, min_mesg_size);
+        CHECK_I(ret, "H5Pset_shared_mesg_index");
+        if (use_btree) {
+            MESSAGE(5, ("----testing with btree index----\n"));
+            ret = H5Pset_shared_mesg_phase_change(fcpl_id, 0, 0);
+            CHECK_I(ret, "H5Pset_shared_mesg_phase_change");
+        } else {
+            MESSAGE(5, ("----testing with normal index----\n"));
+            ret = H5Pset_shared_mesg_phase_change(fcpl_id, list_max, btree_min);
+            CHECK_I(ret, "H5Pset_shared_mesg_phase_change");
+        }
+
+        /* Create empty file */
+        file = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl_id, fapl_id);
+        CHECK_I(file, "H5Fcreate");
+        ret = H5Fclose(file);
+        CHECK_I(ret, "H5Fclose");
+
+        /* Test Open/Write
+         * Add messages to previously-created file */
+        file = H5Fopen(FILENAME, H5F_ACC_RDWR, fapl_id);
+        CHECK_I(file, "H5Fopen");
+        file = size1_helper(file, FILENAME, fapl_id, 0);
+        CHECK_I(file, "size1_helper");
+
+        /* Get the size of a dataset object header */
+        ret = H5Oget_info_by_name2(file, DSETNAME[0], &oinfo, H5O_INFO_HDR, H5P_DEFAULT);
+        CHECK_I(ret, "H5Oget_info_by_name");
+        oh_size_open = oinfo.hdr.space.total;
+
+        ret = H5Fclose(file);
+        CHECK_I(ret, "H5Fclose");
+
+        /* Test Create/Write
+         * Add messages to a newly-created file */
+        file = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl_id, fapl_id);
+        CHECK_I(file, "H5Fcreate");
+        file = size1_helper(file, FILENAME, fapl_id, 0);
+        CHECK_I(file, "size1_helper");
+
+        /* Get the size of a dataset object header */
+        ret = H5Oget_info_by_name2(file, DSETNAME[0], &oinfo, H5O_INFO_HDR, H5P_DEFAULT);
+        CHECK_I(ret, "H5Oget_info_by_name");
+        oh_size_create = oinfo.hdr.space.total;
+
+        ret = H5Fclose(file);
+        CHECK_I(ret, "H5Fclose");
+
+        VERIFY(oh_size_create, oh_size_open, "H5Oget_info_by_name2");
+
+        ret = H5Pclose(fcpl_id);
+        CHECK_I(ret, "H5Pclose");
+    } /* for normal/btree indexing */
+
     ret = H5Pclose(fapl_id);
     CHECK_I(ret, "H5Pclose");
-}
+} /* test_sohm_size_consistency_open_create */
 
 
 /*-------------------------------------------------------------------------
@@ -966,149 +1052,110 @@ static void test_sohm_size1(void)
  *
  * Purpose:     Given an fcpl, tests creating attributes with and without
  *              committed datatypes.
+ *              Verify that an attribute can be written and read back.
+ *              Tests attribute on a Group.
+ *              Tests committed and non-committed datatypes.
+ *              Tests attribute access through `H5Aopen()`.
  *
  * Programmer:  James Laird
  *              Thursday, November 30, 2006
  *
  *-------------------------------------------------------------------------
  */
-static void sohm_attr_helper(hid_t fcpl_id)
+static void
+sohm_attr_helper(hid_t fcpl_id)
 {
     hid_t file_id;
-    hid_t type_id;
     hid_t space_id;
-    hid_t group_id;
-    hid_t attr_id, attr_id2;
     hsize_t dims = 2;
     int wdata[2] = {7, 42};
     int rdata[2];
     herr_t ret;
     size_t x;
+    unsigned op_index=0;
+#define TSOHM_SAH_OP_COUNT 3
+    const char *groupnames[TSOHM_SAH_OP_COUNT] = {
+        "group_for_nothing_special",
+        "group_for_commited_dtype",
+        "group_for_commited_dtype_and_other_ID_access",
+    };
 
-    /*----------------------------------------------------------------------------
-     *    Test attribute with transient datatype
-     */
-    /* Create a file using the fcpl */
     file_id = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl_id, H5P_DEFAULT);
     CHECK_I(file_id, "H5Fcreate");
 
-    /* Create a normal datatype and dataset */
-    type_id = H5Tcopy(H5T_NATIVE_INT);
-    CHECK_I(type_id, "H5Tcopy");
     space_id = H5Screate_simple(1, &dims, &dims);
     CHECK_I(space_id, "H5Screate_simple");
 
-    /* Create and verify an attribute on a group */
-    group_id = H5Gcreate2(file_id, "group", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
-    CHECK_I(group_id, "H5Gcreate2");
-    attr_id = H5Acreate2(group_id, "attribute", type_id, space_id, H5P_DEFAULT, H5P_DEFAULT);
-    CHECK_I(attr_id, "H5Acreate2");
-    ret = H5Awrite(attr_id, H5T_NATIVE_INT, wdata);
-    CHECK_I(ret, "H5Awrite");
-
-    /* Close the datatype and group */
-    ret = H5Tclose(type_id);
-    CHECK_I(ret, "H5Tclose");
-    ret = H5Gclose(group_id);
-    CHECK_I(ret, "H5Gclose");
-
-    /* Flush the file to force data to be written */
-    ret = H5Fflush(file_id, H5F_SCOPE_GLOBAL);
-    CHECK_I(ret, "H5Fflush");
-
-    /* Verify */
-    HDmemset(rdata, 0, sizeof(rdata));
-    ret = H5Aread(attr_id, H5T_NATIVE_INT, rdata);
-    CHECK_I(ret, "H5Aread");
-    for(x = 0; x < (size_t)dims; ++x)
-        VERIFY(rdata[x], wdata[x], "H5Aread");
-
-    /* Cleanup */
-    ret = H5Aclose(attr_id);
-    CHECK_I(ret, "H5Aclose");
-
-    /*----------------------------------------------------------------------------
-     *    Test attribute with committed datatype
+    /* loop:
+     * 0 - nothing special
+     * 1 - committed datatype
+     * 2 - committed datatype, read through second ID
      */
-    /* Repeat with a committed datatype */
-    type_id = H5Tcopy(H5T_NATIVE_INT);
-    CHECK_I(type_id, "H5Tcopy");
-    ret = H5Tcommit2(file_id, "datatype", type_id, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
-    CHECK_I(ret, "H5Tcommit2");
+    for (op_index = 0; op_index < TSOHM_SAH_OP_COUNT; op_index++) {
+        hid_t type_id  = -1;
+        hid_t group_id = -1;
+        hid_t attr_id  = -1;
+        hid_t attr_id2 = -1;
+        hid_t attr_read_id;
 
-    /* Create and verify an attribute */
-    group_id = H5Gcreate2(file_id, "another_group", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
-    CHECK_I(group_id, "H5Gcreate2");
-    attr_id = H5Acreate2(group_id, "attribute", type_id, space_id, H5P_DEFAULT, H5P_DEFAULT);
-    CHECK_I(attr_id, "H5Acreate2");
-    ret = H5Awrite(attr_id, H5T_NATIVE_INT, wdata);
-    CHECK_I(ret, "H5Awrite");
-
-    /* Close the datatype and group */
-    ret = H5Tclose(type_id);
-    CHECK_I(ret, "H5Tclose");
-    ret = H5Gclose(group_id);
-    CHECK_I(ret, "H5Gclose");
+        /* create group in file with name unique to op_index */
+        group_id = H5Gcreate2(file_id, groupnames[op_index], H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+        CHECK_I(group_id, "H5Gcreate2");
 
-    /* Flush the file to force data to be written */
-    ret = H5Fflush(file_id, H5F_SCOPE_GLOBAL);
-    CHECK_I(ret, "H5Fflush");
+        type_id = H5Tcopy(H5T_NATIVE_INT);
+        CHECK_I(type_id, "H5Tcopy");
 
-    /* Verify */
-    HDmemset(rdata, 0, sizeof(rdata));
-    ret = H5Aread(attr_id, H5T_NATIVE_INT, rdata);
-    CHECK_I(ret, "H5Aread");
-    for(x = 0; x < (size_t)dims; ++x)
-        VERIFY(rdata[x], wdata[x], "H5Aread");
-
-    /* Cleanup */
-    ret = H5Aclose(attr_id);
-    CHECK_I(ret, "H5Aclose");
-
-    /*----------------------------------------------------------------------------
-     *    Test attribute operation with two ID handles
-     */
-    /* Create and verify an attribute */
-    group_id = H5Gcreate2(file_id, "yet_another_group", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
-    CHECK_I(group_id, "H5Gcreate2");
-
-    attr_id = H5Acreate2(group_id, "attribute", H5T_NATIVE_INT, space_id, H5P_DEFAULT, H5P_DEFAULT);
-    CHECK_I(attr_id, "H5Acreate2");
+        /* Commit the datatype for the latter iterations.
+         * Only do this ONCE.
+         */
+        if (op_index == 1) {
+            ret = H5Tcommit2(file_id, "datatype", type_id, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+            CHECK_I(ret, "H5Tcommit2");
+        }
 
-    /* Open the attribute to get another handle */
-    attr_id2 = H5Aopen(group_id, "attribute", H5P_DEFAULT);
-    CHECK_I(attr_id2, "H5Aopen");
+        attr_id = H5Acreate2(group_id, "attribute", type_id, space_id, H5P_DEFAULT, H5P_DEFAULT);
+        CHECK_I(attr_id, "H5Acreate2");
 
-    ret = H5Awrite(attr_id, H5T_NATIVE_INT, wdata);
-    CHECK_I(ret, "H5Awrite");
+        if (op_index == 2) {
+            /* Open the attribute to get another handle */
+            attr_id2 = H5Aopen(group_id, "attribute", H5P_DEFAULT);
+            CHECK_I(attr_id2, "H5Aopen");
+        }
 
-    /* Close the group */
-    ret = H5Gclose(group_id);
-    CHECK_I(ret, "H5Gclose");
+        ret = H5Awrite(attr_id, H5T_NATIVE_INT, wdata);
+        CHECK_I(ret, "H5Awrite");
 
-    /* Flush the file to force data to be written */
-    ret = H5Fflush(file_id, H5F_SCOPE_GLOBAL);
-    CHECK_I(ret, "H5Fflush");
+        ret = H5Gclose(group_id);
+        CHECK_I(ret, "H5Gclose");
+        ret = H5Tclose(type_id);
+        CHECK_I(ret, "H5Tclose");
 
-    /* Verify the data with another ID handle */
-    HDmemset(rdata, 0, sizeof(rdata));
-    ret = H5Aread(attr_id2, H5T_NATIVE_INT, rdata);
-    CHECK_I(ret, "H5Aread");
+        /* Flush the file to force data to be written */
+        ret = H5Fflush(file_id, H5F_SCOPE_GLOBAL);
+        CHECK_I(ret, "H5Fflush");
 
-    for(x = 0; x < (size_t)dims; ++x)
-        VERIFY(rdata[x], wdata[x], "H5Aread");
+        /* Verify */
+        attr_read_id = (op_index == 2) ? attr_id2 : attr_id;
+        HDmemset(rdata, 0, sizeof(rdata));
+        ret = H5Aread(attr_read_id, H5T_NATIVE_INT, rdata);
+        CHECK_I(ret, "H5Aread");
+        for(x = 0; x < (size_t)dims; ++x)
+            VERIFY(rdata[x], wdata[x], "H5Aread");
 
-    /* Cleanup */
-    ret = H5Aclose(attr_id);
-    CHECK_I(ret, "H5Aclose");
-    ret = H5Aclose(attr_id2);
-    CHECK_I(ret, "H5Aclose");
+        ret = H5Aclose(attr_id);
+        CHECK_I(ret, "H5Aclose");
+        if (attr_id2 > -1 ) {
+            ret = H5Aclose(attr_id2);
+            CHECK_I(ret, "H5Aclose");
+        }
+    } /* for each attribute operation */
 
     ret = H5Sclose(space_id);
     CHECK_I(ret, "H5Sclose");
     ret = H5Fclose(file_id);
     CHECK_I(ret, "H5Fclose");
-}
+#undef TSOHM_SAH_OP_COUNT
+} /* sohm_attr_helper */
 
 
 /*-------------------------------------------------------------------------
@@ -1125,101 +1172,160 @@ static void sohm_attr_helper(hid_t fcpl_id)
  *
  *-------------------------------------------------------------------------
  */
-static void test_sohm_attrs(void)
+static void
+test_sohm_attrs(void)
 {
     hid_t fcpl_id;
+    unsigned i = 0;
+#define TSOHM_TSA_NFLAGS_1 7
+    unsigned flags1[TSOHM_TSA_NFLAGS_1] = {
+        H5O_SHMESG_ATTR_FLAG,
+        H5O_SHMESG_SDSPACE_FLAG,
+        H5O_SHMESG_DTYPE_FLAG,
+        H5O_SHMESG_ATTR_FLAG | H5O_SHMESG_SDSPACE_FLAG,
+        H5O_SHMESG_SDSPACE_FLAG | H5O_SHMESG_DTYPE_FLAG,
+        H5O_SHMESG_ATTR_FLAG | H5O_SHMESG_DTYPE_FLAG,
+        H5O_SHMESG_ATTR_FLAG | H5O_SHMESG_SDSPACE_FLAG | H5O_SHMESG_DTYPE_FLAG,
+    };
+#define TSOHM_TSA_NFLAGS_2 6
+    unsigned flags2[TSOHM_TSA_NFLAGS_2][2] = {
+        {   H5O_SHMESG_ATTR_FLAG,
+            H5O_SHMESG_SDSPACE_FLAG | H5O_SHMESG_DTYPE_FLAG,
+        },
+        {   H5O_SHMESG_SDSPACE_FLAG,
+            H5O_SHMESG_ATTR_FLAG | H5O_SHMESG_DTYPE_FLAG,
+        },
+        {   H5O_SHMESG_DTYPE_FLAG,
+            H5O_SHMESG_ATTR_FLAG | H5O_SHMESG_SDSPACE_FLAG,
+        },
+        {   H5O_SHMESG_SDSPACE_FLAG | H5O_SHMESG_DTYPE_FLAG,
+            H5O_SHMESG_ATTR_FLAG,
+        },
+        {   H5O_SHMESG_ATTR_FLAG | H5O_SHMESG_DTYPE_FLAG,
+            H5O_SHMESG_SDSPACE_FLAG,
+        },
+        {   H5O_SHMESG_ATTR_FLAG | H5O_SHMESG_SDSPACE_FLAG,
+            H5O_SHMESG_DTYPE_FLAG,
+        },
+    };
+#define TSOHM_TSA_NFLAGS_3 5
+    unsigned flags3[TSOHM_TSA_NFLAGS_3][3] = {
+        {   H5O_SHMESG_ATTR_FLAG,
+            H5O_SHMESG_SDSPACE_FLAG,
+            H5O_SHMESG_DTYPE_FLAG,
+        },
+        {   H5O_SHMESG_DTYPE_FLAG,
+            H5O_SHMESG_ATTR_FLAG,
+            H5O_SHMESG_SDSPACE_FLAG,
+        },
+        {   H5O_SHMESG_SDSPACE_FLAG,
+            H5O_SHMESG_DTYPE_FLAG,
+            H5O_SHMESG_ATTR_FLAG,
+        },
+        {   0, /* first index does not hold a shared message type? */
+            H5O_SHMESG_SDSPACE_FLAG | H5O_SHMESG_DTYPE_FLAG,
+            H5O_SHMESG_ATTR_FLAG,
+        },
+        {   0, /* missing SDSPACE flag */
+            H5O_SHMESG_DTYPE_FLAG,
+            H5O_SHMESG_ATTR_FLAG,
+        },
+    };
     herr_t ret;
 
     MESSAGE(5, ("Testing that shared messages work with attributes\n"));
 
-    /* Create an fcpl with no shared messages */
+    /* No shared messages
+     */
     fcpl_id = H5Pcreate(H5P_FILE_CREATE);
     CHECK_I(fcpl_id, "H5Pcreate");
     ret = H5Pset_shared_mesg_nindexes(fcpl_id, 0);
     CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
 
-    /* Make sure attributes can be read with these settings (they'd better!) */
-    sohm_attr_helper(fcpl_id);
-
-
-    /* Run tests with only one kind of message to be shared */
-    ret = H5Pset_shared_mesg_nindexes(fcpl_id, 1);
-    CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
-    ret = H5Pset_shared_mesg_index(fcpl_id, 0, H5O_SHMESG_ATTR_FLAG, 2);
-    CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
-
-    /* Verify */
-    sohm_attr_helper(fcpl_id);
-
-    ret = H5Pset_shared_mesg_index(fcpl_id, 0, H5O_SHMESG_SDSPACE_FLAG, 2);
-    CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
-
-    sohm_attr_helper(fcpl_id);
-
-    ret = H5Pset_shared_mesg_index(fcpl_id, 0, H5O_SHMESG_DTYPE_FLAG, 2);
-    CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
-
-    sohm_attr_helper(fcpl_id);
-
-
-    /* Run with any two types shared */
-    ret = H5Pset_shared_mesg_index(fcpl_id, 0, H5O_SHMESG_SDSPACE_FLAG | H5O_SHMESG_DTYPE_FLAG, 2);
-    CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
-
     sohm_attr_helper(fcpl_id);
 
-    ret = H5Pset_shared_mesg_index(fcpl_id, 0, H5O_SHMESG_ATTR_FLAG | H5O_SHMESG_DTYPE_FLAG, 2);
-    CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
-
-    sohm_attr_helper(fcpl_id);
-
-    ret = H5Pset_shared_mesg_index(fcpl_id, 0, H5O_SHMESG_SDSPACE_FLAG | H5O_SHMESG_ATTR_FLAG, 2);
-    CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
-
-    sohm_attr_helper(fcpl_id);
-
-
-    /* Run test with all three kinds of message shared */
-    ret = H5Pset_shared_mesg_index(fcpl_id, 0, H5O_SHMESG_SDSPACE_FLAG | H5O_SHMESG_DTYPE_FLAG | H5O_SHMESG_ATTR_FLAG, 2);
-    CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
+    ret = H5Pclose(fcpl_id);
+    CHECK_I(ret, "H5Pclose");
 
-    sohm_attr_helper(fcpl_id);
+    /* One shared message index
+     */
+    for (i=0; i < TSOHM_TSA_NFLAGS_1; i++) {
+        fcpl_id = H5Pcreate(H5P_FILE_CREATE);
+        CHECK_I(fcpl_id, "H5Pcreate");
+        ret = H5Pset_shared_mesg_nindexes(fcpl_id, 1);
+        CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
+        ret = H5Pset_shared_mesg_index(fcpl_id, 0, flags1[i], 2);
+        CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
 
+        sohm_attr_helper(fcpl_id);
 
-    /* Try using two indexes */
-    ret = H5Pset_shared_mesg_nindexes(fcpl_id, 2);
-    CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
-    ret = H5Pset_shared_mesg_index(fcpl_id, 0, H5O_SHMESG_ATTR_FLAG | H5O_SHMESG_DTYPE_FLAG, 2);
-    CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
-    ret = H5Pset_shared_mesg_index(fcpl_id, 1, H5O_SHMESG_SDSPACE_FLAG, 2);
-    CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
+        ret = H5Pclose(fcpl_id);
+        CHECK_I(ret, "H5Pclose");
+    }
 
-    sohm_attr_helper(fcpl_id);
+    /* two shared message indices
+     */
+    for (i=0; i < TSOHM_TSA_NFLAGS_2; i++) {
+        fcpl_id = H5Pcreate(H5P_FILE_CREATE);
+        CHECK_I(fcpl_id, "H5Pcreate");
+        ret = H5Pset_shared_mesg_nindexes(fcpl_id, 2);
+        CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
+        ret = H5Pset_shared_mesg_index(fcpl_id, 0, flags2[i][0], 2);
+        CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
+        ret = H5Pset_shared_mesg_index(fcpl_id, 1, flags2[i][1], 2);
+        CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
 
-    ret = H5Pset_shared_mesg_index(fcpl_id, 0, H5O_SHMESG_DTYPE_FLAG, 2);
-    CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
+        sohm_attr_helper(fcpl_id);
 
-    sohm_attr_helper(fcpl_id);
+        ret = H5Pclose(fcpl_id);
+        CHECK_I(ret, "H5Pclose");
+    }
 
-    ret = H5Pset_shared_mesg_index(fcpl_id, 1, H5O_SHMESG_ATTR_FLAG, 2);
-    CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
+    /* duplicate flags in separate indices causes problems
+     */
+    H5E_BEGIN_TRY {
+        fcpl_id = H5Pcreate(H5P_FILE_CREATE);
+        CHECK_I(fcpl_id, "H5Pcreate");
+        ret = H5Pset_shared_mesg_nindexes(fcpl_id, 2);
+        CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
+        ret = H5Pset_shared_mesg_index(fcpl_id, 0, H5O_SHMESG_ATTR_FLAG, 2);
+        CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
+        ret = H5Pset_shared_mesg_index(fcpl_id, 1, H5O_SHMESG_ATTR_FLAG, 2);
+        CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
+
+        ret = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl_id, H5P_DEFAULT);
+        VERIFY(ret, -1, "H5Fcreate");
+
+        ret = H5Pclose(fcpl_id);
+        CHECK_I(ret, "H5Pclose");
+    } H5E_END_TRY;
 
-    sohm_attr_helper(fcpl_id);
+    /* three shared message indices
+     */
+    for (i=0; i < TSOHM_TSA_NFLAGS_3; i++) {
+        fcpl_id = H5Pcreate(H5P_FILE_CREATE);
+        CHECK_I(fcpl_id, "H5Pcreate");
+        ret = H5Pset_shared_mesg_nindexes(fcpl_id, 3);
+        CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
+        ret = H5Pset_shared_mesg_index(fcpl_id, 0, flags3[i][0], 2);
+        CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
+        ret = H5Pset_shared_mesg_index(fcpl_id, 1, flags3[i][1], 2);
+        CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
+        ret = H5Pset_shared_mesg_index(fcpl_id, 2, flags3[i][2], 2);
+        CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
 
+        sohm_attr_helper(fcpl_id);
 
-    /* One index for each kind of message */
-    ret = H5Pset_shared_mesg_nindexes(fcpl_id, 3);
-    CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
-    ret = H5Pset_shared_mesg_index(fcpl_id, 2, H5O_SHMESG_SDSPACE_FLAG, 2);
-    CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
+        ret = H5Pclose(fcpl_id);
+        CHECK_I(ret, "H5Pclose");
+    }
 
-    sohm_attr_helper(fcpl_id);
+#undef TSOHM_TSA_NFLAGS_1
+#undef TSOHM_TSA_NFLAGS_2
+#undef TSOHM_TSA_NFLAGS_3
 
+} /* test_sohm_attrs */
 
-    /* Close the FCPL */
-    ret = H5Pclose(fcpl_id);
-    CHECK_I(ret, "H5Pclose");
-}
 
 /*-------------------------------------------------------------------------
  * Function:    size2_verify_plist1
@@ -1233,7 +1339,8 @@ static void test_sohm_attrs(void)
  *
  *-------------------------------------------------------------------------
  */
-static void size2_verify_plist1(hid_t plist)
+static void
+size2_verify_plist1(hid_t plist)
 {
     size_t cd_nelmts;
     unsigned int cd_value;
@@ -1281,7 +1388,8 @@ static void size2_verify_plist1(hid_t plist)
 
     ret = H5Tclose(dtype1_id);
     CHECK_I(ret, "H5Tclose");
-}
+} /* size2_verify_plist1 */
+
 
 /*-------------------------------------------------------------------------
  * Function:    size2_verify_plist2
@@ -1295,7 +1403,8 @@ static void size2_verify_plist1(hid_t plist)
  *
  *-------------------------------------------------------------------------
  */
-static void size2_verify_plist2(hid_t plist)
+static void
+size2_verify_plist2(hid_t plist)
 {
     size_t cd_nelmts;
     unsigned int cd_value;
@@ -1352,7 +1461,7 @@ static void size2_verify_plist2(hid_t plist)
 
     ret = H5Tclose(dtype2_id);
     CHECK_I(ret, "H5Tclose");
-}
+} /* size2_verify_plist2 */
 
 #ifdef NOT_NOW
 
@@ -1382,7 +1491,7 @@ size2_dump_struct(const char *name, size2_helper_struct *sizes)
   printf("   interleaved: %llu \tdelta: %llu\n", (unsigned long long)sizes->interleaved, (unsigned long long)(sizes->interleaved - sizes->dsets2));
   printf("    attributes: %llu \tdelta: %llu\n", (unsigned long long)sizes->attrs1, (unsigned long long)(sizes->attrs1 - sizes->interleaved));
   printf("  attributes 2: %llu \tdelta: %llu\n", (unsigned long long)sizes->attrs2, (unsigned long long)(sizes->attrs2 - sizes->attrs1));
-}
+} /* size2_dump_struct */
 #endif /* NOT_NOW */
 
 
@@ -1573,15 +1682,14 @@ size2_helper(hid_t fcpl_id, int test_file_closing, size2_helper_struct *ret_size
     ret_sizes->dsets1 = h5_get_file_size(FILENAME, H5P_DEFAULT);
 
 
-    /* Now create a new group filled with datasets that use all different messages */
+    /* Create new group filled with datasets that use all different messages */
     file_id = H5Fopen(FILENAME, H5F_ACC_RDWR, H5P_DEFAULT);
     CHECK_I(file_id, "H5Fopen");
     group_id = H5Gcreate2(file_id, "group", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
     CHECK_I(group_id, "H5Gcreate2");
 
     /* Create NUM_DATASETS datasets in the new group */
-    for(x=0; x<NUM_DATASETS; ++x)
-    {
+    for(x=0; x<NUM_DATASETS; ++x) {
         dset_id = H5Dcreate2(group_id, DSETNAME[x], dtype2_id, dspace2_id, H5P_DEFAULT, dcpl2_id, H5P_DEFAULT);
         CHECK_I(dset_id, "H5Dcreate2");
 
@@ -1768,7 +1876,7 @@ size2_helper(hid_t fcpl_id, int test_file_closing, size2_helper_struct *ret_size
     CHECK_I(ret, "H5Pclose");
 
     return 0;
-}
+} /* size2_helper */
 
 
 /*-------------------------------------------------------------------------
@@ -1785,7 +1893,8 @@ size2_helper(hid_t fcpl_id, int test_file_closing, size2_helper_struct *ret_size
  *
  *-------------------------------------------------------------------------
  */
-static void size2_verify(void)
+static void
+size2_verify(void)
 {
     hid_t file_id = -1;
     hid_t dset_id=-1;
@@ -1968,7 +2077,7 @@ static void size2_verify(void)
     CHECK_I(ret, "H5Gclose");
     ret = H5Fclose(file_id);
     CHECK_I(ret, "H5Fclose");
-}
+} /* size2_verify */
 
 
 /*-------------------------------------------------------------------------
@@ -1993,7 +2102,8 @@ static void size2_verify(void)
  *
  *-------------------------------------------------------------------------
  */
-static void test_sohm_size2(int close_reopen)
+static void
+test_sohm_size2(int close_reopen)
 {
     hid_t       fcpl_id = -1;
     /* Sizes for file with no shared messages at all */
@@ -2585,7 +2695,7 @@ static void test_sohm_size2(int close_reopen)
         VERIFY(0, 1, "h5_get_file_size");
     if((h5_stat_size_t)((float)share_tiny_index.attrs2 * OVERHEAD_ALLOWED) < type_space_index.attrs2)
         VERIFY(0, 1, "h5_get_file_size");
-} /* end test_sohm_size2() */
+} /* test_sohm_size2 */
 
 
 /*-------------------------------------------------------------------------
@@ -2601,27 +2711,22 @@ static void test_sohm_size2(int close_reopen)
  *
  *-------------------------------------------------------------------------
  */
-static void delete_helper_write(hid_t file_id, hid_t *dspace_id, hid_t *dcpl_id, int x)
+static void
+delete_helper_write(hid_t file_id, hid_t *dspace_id, hid_t *dcpl_id, int x)
 {
-    hid_t dset_id = -1;
-    hid_t attr_id = -1;
-    char wdata;
+    hid_t  dset_id = -1;
+    hid_t  attr_id = -1;
+    char   wdata;
     herr_t ret;
 
-    /* Create dataset */
     dset_id = H5Dcreate2(file_id, DSETNAME[x], H5T_NATIVE_CHAR, dspace_id[x], H5P_DEFAULT, dcpl_id[x], H5P_DEFAULT);
     CHECK_I(dset_id, "H5Dcreate2");
-
-    /* Write data to dataset */
     wdata = (char)(x + 'a');
     ret = H5Dwrite(dset_id, H5T_NATIVE_CHAR, dspace_id[x], dspace_id[x], H5P_DEFAULT, &wdata);
     CHECK_I(ret, "H5Dwrite");
 
-    /* Create an attribute on the dataset. */
     attr_id = H5Acreate2(dset_id, "attr_name", H5T_NATIVE_CHAR, dspace_id[x], H5P_DEFAULT, H5P_DEFAULT);
     CHECK_I(attr_id, "H5Acreate2");
-
-    /* Write to attribute */
     ret = H5Awrite(attr_id, H5T_NATIVE_CHAR, &wdata);
     CHECK_I(ret, "H5Awrite");
 
@@ -2629,7 +2734,7 @@ static void delete_helper_write(hid_t file_id, hid_t *dspace_id, hid_t *dcpl_id,
     CHECK_I(ret, "H5Aclose");
     ret = H5Dclose(dset_id);
     CHECK_I(ret, "H5Dclose");
-}
+} /* delete_helper_write */
 
 
 /*-------------------------------------------------------------------------
@@ -2645,39 +2750,33 @@ static void delete_helper_write(hid_t file_id, hid_t *dspace_id, hid_t *dcpl_id,
  *
  *-------------------------------------------------------------------------
  */
-static void delete_helper_read(hid_t file_id, hid_t *dspace_id, int x)
+static void
+delete_helper_read(hid_t file_id, hid_t *dspace_id, int x)
 {
     hid_t dset_id = -1;
     hid_t attr_id = -1;
     char rdata;
     herr_t ret;
 
-    /* Open dataset */
     dset_id = H5Dopen2(file_id, DSETNAME[x], H5P_DEFAULT);
     CHECK_I(dset_id, "H5Dopen2");
-
-    /* Read */
     rdata = '\0';
     ret = H5Dread(dset_id, H5T_NATIVE_CHAR, dspace_id[x], dspace_id[x], H5P_DEFAULT, &rdata);
     CHECK_I(ret, "H5Dread");
     VERIFY(rdata, (x + 'a'), "H5Dread");
 
-    /* Open attribute */
     attr_id = H5Aopen(dset_id, "attr_name", H5P_DEFAULT);
     CHECK_I(attr_id, "H5Aopen");
-
-    /* Read */
     rdata = '\0';
     ret = H5Aread(attr_id, H5T_NATIVE_CHAR, &rdata);
     CHECK_I(ret, "H5Dread");
     VERIFY(rdata, (x + 'a'), "H5Dread");
 
-    /* Cleanup */
     ret = H5Aclose(attr_id);
     CHECK_I(ret, "H5Aclose");
     ret = H5Dclose(dset_id);
     CHECK_I(ret, "H5Dclose");
-}
+} /* delete_helper_read */
 
 
 /*-------------------------------------------------------------------------
@@ -2701,7 +2800,8 @@ static void delete_helper_read(hid_t file_id, hid_t *dspace_id, int x)
  *
  *-------------------------------------------------------------------------
  */
-static void delete_helper(hid_t fcpl_id, hid_t *dspace_id, hid_t *dcpl_id)
+static void
+delete_helper(hid_t fcpl_id, hid_t *dspace_id, hid_t *dcpl_id)
 {
     hid_t file_id=-1;
     int x;
@@ -2765,7 +2865,7 @@ static void delete_helper(hid_t fcpl_id, hid_t *dspace_id, hid_t *dcpl_id)
         VERIFY(norm_filesize, deleted_filesize, "h5_get_file_size");
     if(deleted_filesize > (h5_stat_size_t)((float)norm_filesize * OVERHEAD_ALLOWED))
         VERIFY(deleted_filesize, norm_filesize, "h5_get_file_size");
-}
+} /* delete_helper */
 
 
 /*-------------------------------------------------------------------------
@@ -2799,6 +2899,8 @@ test_sohm_delete(void)
     hsize_t dims[] = DELETE_DIMS;
     herr_t ret;
 
+    MESSAGE(5, ("Testing deletion of SOHMs\n"));
+
     /* Create a number of different dataspaces.
      * For simplicity, each dataspace has only one element.
      */
@@ -2910,17 +3012,18 @@ test_sohm_delete(void)
         ret = H5Pclose(dcpl_id[x]);
         CHECK_I(ret, "H5Pclose");
     } /* end for */
-} /* end test_sohm_delete() */
+} /* test_sohm_delete */
 
 
 /*-------------------------------------------------------------------------
- * Function:    test_sohm_delete_revert_helper
+ * Function:    verify_dset_create_and_delete_does_not_grow_file
  *
  * Purpose:     Tests that shared object header message deletion returns
  *              the file to its previous state using the supplied FCPL.
  *
- *              Creates shared messages and then deletes them.  Ensures
- *              that the file has not grown in size.
+ *              Creates a file according to the supplied FCPL,
+ *              then creates datasets and deletes them.
+ *              Done in two passes: once with one dataset, once with two.
  *
  * Programmer:  James Laird
  *              Wednesday, January 3, 2007
@@ -2930,7 +3033,7 @@ test_sohm_delete(void)
  *-------------------------------------------------------------------------
  */
 static int
-test_sohm_delete_revert_helper(hid_t fcpl_id)
+verify_dset_create_and_delete_does_not_grow_file(hid_t fcpl_id)
 {
     hid_t file_id;
     hid_t dspace_id;
@@ -3017,13 +3120,14 @@ test_sohm_delete_revert_helper(hid_t fcpl_id)
         return(0);
     else
         return(-1);
-} /* test_sohm_delete_revert_helper() */
+} /* verify_dset_create_and_delete_does_not_grow_file */
 
 
 /*-------------------------------------------------------------------------
  * Function:    test_sohm_delete_revert
  *
- * Purpose:     Calls test_sohm_delete_revert_helper with different FCPLs.
+ * Purpose:     Verifies that creation and deletion of datasets with shared
+ *              message headers will not increase file size.
  *
  * Programmer:  James Laird
  *              Wednesday, January 3, 2007
@@ -3038,6 +3142,8 @@ test_sohm_delete_revert(void)
     hid_t fcpl_id;
     herr_t ret;
 
+    MESSAGE(5, ("Testing that file reverts to original size on SOHM deletion\n"));
+
     /* Create an fcpl with messages in two indexes */
     fcpl_id = H5Pcreate(H5P_FILE_CREATE);
     CHECK_I(fcpl_id, "H5Pcreate");
@@ -3049,14 +3155,14 @@ test_sohm_delete_revert(void)
     CHECK_I(ret, "H5Pset_shared_mesg_index");
 
     /* Call the helper function to test this FCPL. */
-    ret = test_sohm_delete_revert_helper(fcpl_id);
-    CHECK_I(ret, "test_sohm_delete_revert_helper");
+    ret = verify_dset_create_and_delete_does_not_grow_file(fcpl_id);
+    CHECK_I(ret, "verify_dset_create_and_delete_does_not_grow_file");
 
     /* Try using B-trees */
     ret = H5Pset_shared_mesg_phase_change(fcpl_id, 0, 0);
     CHECK_I(ret, "H5Pset_shared_mesg_phase_change");
-    ret = test_sohm_delete_revert_helper(fcpl_id);
-    CHECK_I(ret, "test_sohm_delete_revert_helper");
+    ret = verify_dset_create_and_delete_does_not_grow_file(fcpl_id);
+    CHECK_I(ret, "verify_dset_create_and_delete_does_not_grow_file");
 
 
     /* Try sharing all messages */
@@ -3067,14 +3173,14 @@ test_sohm_delete_revert(void)
     ret = H5Pset_shared_mesg_phase_change(fcpl_id, 10, 5);
     CHECK_I(ret, "H5Pset_shared_mesg_phase_change");
 
-    ret = test_sohm_delete_revert_helper(fcpl_id);
-    CHECK_I(ret, "test_sohm_delete_revert_helper");
+    ret = verify_dset_create_and_delete_does_not_grow_file(fcpl_id);
+    CHECK_I(ret, "verify_dset_create_and_delete_does_not_grow_file");
 
     /* Try using B-trees */
     ret = H5Pset_shared_mesg_phase_change(fcpl_id, 0, 0);
     CHECK_I(ret, "H5Pset_shared_mesg_phase_change");
-    ret = test_sohm_delete_revert_helper(fcpl_id);
-    CHECK_I(ret, "test_sohm_delete_revert_helper");
+    ret = verify_dset_create_and_delete_does_not_grow_file(fcpl_id);
+    CHECK_I(ret, "verify_dset_create_and_delete_does_not_grow_file");
 
     /* There should be at least two messages in the test (datatype and
      * dataspace).  Use an index that will transition from a list to
@@ -3082,8 +3188,8 @@ test_sohm_delete_revert(void)
      */
     ret = H5Pset_shared_mesg_phase_change(fcpl_id, 1, 2);
     CHECK_I(ret, "H5Pset_shared_mesg_phase_change");
-    ret = test_sohm_delete_revert_helper(fcpl_id);
-    CHECK_I(ret, "test_sohm_delete_revert_helper");
+    ret = verify_dset_create_and_delete_does_not_grow_file(fcpl_id);
+    CHECK_I(ret, "verify_dset_create_and_delete_does_not_grow_file");
 
 
     /* Try with shared messages enabled, but when messages are too big
@@ -3091,16 +3197,16 @@ test_sohm_delete_revert(void)
      */
     ret = H5Pset_shared_mesg_index(fcpl_id, 0, H5O_SHMESG_ALL_FLAG, 35);
     CHECK_I(ret, "H5Pset_shared_mesg_phase_change");
-    ret = test_sohm_delete_revert_helper(fcpl_id);
-    CHECK_I(ret, "test_sohm_delete_revert_helper");
+    ret = verify_dset_create_and_delete_does_not_grow_file(fcpl_id);
+    CHECK_I(ret, "verify_dset_create_and_delete_does_not_grow_file");
 
     ret = H5Pclose(fcpl_id);
     CHECK_I(ret, "H5Pclose");
-}
+} /* test_sohm_delete_revert */
 
 
 /*-------------------------------------------------------------------------
- * Function:    test_sohm_extlink_helper
+ * Function:    verify_dset_create_and_open_through_extlink_with_sohm
  *
  * Purpose:     Tests that a dataset created through an external link can
  *              be opened (that shared messages were created or not and
@@ -3113,7 +3219,8 @@ test_sohm_delete_revert(void)
  *
  *-------------------------------------------------------------------------
  */
-static void test_sohm_extlink_helper(hid_t src_fcpl_id, hid_t dst_fcpl_id)
+static void
+verify_dset_create_and_open_through_extlink_with_sohm(hid_t src_fcpl_id, hid_t dst_fcpl_id)
 {
     hid_t src_file_id = -1;
     hid_t dst_file_id = -1;
@@ -3164,7 +3271,7 @@ static void test_sohm_extlink_helper(hid_t src_fcpl_id, hid_t dst_fcpl_id)
     CHECK_I(ret, "H5Dclose");
     ret = H5Fclose(dst_file_id);
     CHECK_I(ret, "H5Fclose");
-}
+} /* verify_dset_create_and_open_through_extlink_with_sohm */
 
 
 /*-------------------------------------------------------------------------
@@ -3186,7 +3293,8 @@ test_sohm_extlink(void)
     hid_t fcpl_id = -1;
     herr_t ret;
 
-    /* Create fcpl */
+    MESSAGE(5, ("Testing SOHM creation through external links\n"));
+
     fcpl_id = H5Pcreate(H5P_FILE_CREATE);
     CHECK_I(fcpl_id, "H5Pcreate");
     ret = H5Pset_shared_mesg_nindexes(fcpl_id, 1);
@@ -3194,20 +3302,17 @@ test_sohm_extlink(void)
     ret = H5Pset_shared_mesg_index(fcpl_id, 0, H5O_SHMESG_ALL_FLAG, 16);
     CHECK_I(ret, "H5Pset_shared_mesg_index");
 
-    /* Test using external links when the source or destination file uses
-     * shared messages
-     */
-    test_sohm_extlink_helper(fcpl_id, H5P_DEFAULT);
-    test_sohm_extlink_helper(H5P_DEFAULT, fcpl_id);
-    test_sohm_extlink_helper(fcpl_id, fcpl_id);
+    verify_dset_create_and_open_through_extlink_with_sohm(fcpl_id, H5P_DEFAULT);
+    verify_dset_create_and_open_through_extlink_with_sohm(H5P_DEFAULT, fcpl_id);
+    verify_dset_create_and_open_through_extlink_with_sohm(fcpl_id, fcpl_id);
 
     ret = H5Pclose(fcpl_id);
     CHECK_I(ret, "H5Pclose");
-}
+} /* test_sohm_extlink */
 
 
 /*-------------------------------------------------------------------------
- * Function:    test_sohm_extend_dset_helper
+ * Function:    verify_dataset_extension
  *
  * Purpose:     Tests extending a dataset's dataspace when sharing is
  *              enabled.
@@ -3223,7 +3328,7 @@ test_sohm_extlink(void)
  *-------------------------------------------------------------------------
  */
 static int
-test_sohm_extend_dset_helper(hid_t fcpl_id, hbool_t close_reopen)
+verify_dataset_extension(hid_t fcpl_id, hbool_t close_reopen)
 {
     hid_t file_id = -1;
     hid_t orig_space_id = -1;
@@ -3236,13 +3341,98 @@ test_sohm_extend_dset_helper(hid_t fcpl_id, hbool_t close_reopen)
     hsize_t out_dims[2];
     hsize_t out_maxdims[2];
     int x;
-    int old_nerrs;              /* Number of errors when entering this routine */
+    int old_nerrs;           /* Number of errors when entering this routine */
     herr_t ret;
 
-    /* Retrieve the current # of reported errors */
+    hsize_t *space_dims[3];
+
+/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+ * Macro:      TSOHM_VDE_VERIFY_SPACES
+ *
+ * Purpose:    Encapsulate a common pattern
+ *             Open, read-verify, and close the dataspaces for datasets 1-3
+ *
+ * Programmer: Jacob Smith
+ *             2018 November 5
+ * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+ */
+#define TSOHM_VDE_VERIFY_SPACES(dims)                                     \
+{                                                                         \
+    /* Open dataspaces                                                    \
+     */                                                                   \
+    space1_id = H5Dget_space(dset1_id);                                   \
+    CHECK_I(space1_id, "H5Dget_space");                                   \
+    space2_id = H5Dget_space(dset2_id);                                   \
+    CHECK_I(space2_id, "H5Dget_space");                                   \
+    space3_id = H5Dget_space(dset3_id);                                   \
+    CHECK_I(space3_id, "H5Dget_space");                                   \
+    /* Verify dataspaces                                                  \
+     */                                                                   \
+    ret = H5Sget_simple_extent_dims(space1_id, out_dims, out_maxdims);    \
+    CHECK_I(ret, "H5Sget_simple_extent_dims");                            \
+    for(x=0; x<EXTEND_NDIMS; ++x) {                                       \
+        VERIFY(out_dims[x], (dims)[0][x], "H5Sget_simple_extent_dims");   \
+        VERIFY(out_maxdims[x], max_dims[x], "H5Sget_simple_extent_dims"); \
+    }                                                                     \
+    ret = H5Sget_simple_extent_dims(space2_id, out_dims, out_maxdims);    \
+    CHECK_I(ret, "H5Sget_simple_extent_dims");                            \
+    for(x=0; x<EXTEND_NDIMS; ++x) {                                       \
+        VERIFY(out_dims[x], (dims)[1][x], "H5Sget_simple_extent_dims");   \
+        VERIFY(out_maxdims[x], max_dims[x], "H5Sget_simple_extent_dims"); \
+    }                                                                     \
+    ret = H5Sget_simple_extent_dims(space3_id, out_dims, out_maxdims);    \
+    CHECK_I(ret, "H5Sget_simple_extent_dims");                            \
+    for(x=0; x<EXTEND_NDIMS; ++x) {                                       \
+        VERIFY(out_dims[x], (dims)[2][x], "H5Sget_simple_extent_dims");   \
+        VERIFY(out_maxdims[x], max_dims[x], "H5Sget_simple_extent_dims"); \
+    }                                                                     \
+    /* Close dataspaces                                                   \
+     */                                                                   \
+    CHECK_I(H5Sclose(space1_id), "H5Sclose");                             \
+    CHECK_I(H5Sclose(space2_id), "H5Sclose");                             \
+    CHECK_I(H5Sclose(space3_id), "H5Sclose");                             \
+} /* define TSOHM_VDE_VERIFY_SPACES */
+
+/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+ * Macro:      TSOHM_VDE_CLOSE_REOPEN_FILE_AND_DSETS()
+ *
+ * Purpose:    Encapsulate a common pattern
+ *             Wrapper to close and reopen file and datasets:
+ *                + "dataset" (dset_id)
+ *                + if n > 1 then include "dataset2" (dset_id2)
+ *                + if n > 2 then include "dataset3" (dset_id3)
+ *                + file (file_id)
+ *
+ * Programmer: Jacob Smith
+ *             2018 November 5
+ * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+ */
+#define TSOHM_VDE_CLOSE_REOPEN_FILE_AND_DSETS(n)               \
+{                                                              \
+    CHECK_I(H5Dclose(dset1_id), "H5Dclose");                   \
+    if ((n) > 1)                                               \
+        CHECK_I(H5Dclose(dset2_id), "H5Dclose");               \
+    if ((n) > 2)                                               \
+        CHECK_I(H5Dclose(dset3_id), "H5Dclose");               \
+    CHECK_I(H5Fclose(file_id), "H5Fclose");                    \
+                                                               \
+    file_id = H5Fopen(FILENAME, H5F_ACC_RDWR, H5P_DEFAULT);    \
+    CHECK_I(file_id, "H5Fopen");                               \
+    dset1_id = H5Dopen2(file_id, "dataset", H5P_DEFAULT);      \
+    CHECK_I(dset1_id, "H5Dopen2");                             \
+    if ((n) > 1) {                                             \
+        dset2_id = H5Dopen2(file_id, "dataset2", H5P_DEFAULT); \
+        CHECK_I(dset2_id, "H5Dopen2");                         \
+    }                                                          \
+    if ((n) > 2) {                                             \
+        dset3_id = H5Dopen2(file_id, "dataset3", H5P_DEFAULT); \
+        CHECK_I(dset3_id, "H5Dopen2");                         \
+    }                                                          \
+} /* define TSOHM_VDE_CLOSE_REOPEN_FILE_AND_DSETS */
+
+    /* Remember the current # of reported errors */
     old_nerrs = GetTestNumErrs();
 
-    /* Create file */
     file_id = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl_id, H5P_DEFAULT);
     CHECK_I(file_id, "H5Fcreate");
 
@@ -3257,251 +3447,49 @@ test_sohm_extend_dset_helper(hid_t fcpl_id, hbool_t close_reopen)
     CHECK_I(orig_space_id, "H5Screate_simple");
     dset1_id = H5Dcreate2(file_id, "dataset", H5T_NATIVE_LONG, orig_space_id, H5P_DEFAULT, dcpl_id, H5P_DEFAULT);
     CHECK_I(dset1_id, "H5Dcreate2");
-
-    if(close_reopen) {
-        /* If requested, close all open IDs and reopen them */
-        ret = H5Dclose(dset1_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Fclose(file_id);
-        CHECK_I(ret, "H5Fclose");
-
-        file_id = H5Fopen(FILENAME, H5F_ACC_RDWR, H5P_DEFAULT);
-        CHECK_I(file_id, "H5Fopen");
-        dset1_id = H5Dopen2(file_id, "dataset", H5P_DEFAULT);
-        CHECK_I(dset1_id, "H5Dopen2");
-    }
+    if(close_reopen)
+        TSOHM_VDE_CLOSE_REOPEN_FILE_AND_DSETS(1);
 
     /* Create another dataset starting with the same dataspace */
     dset2_id = H5Dcreate2(file_id, "dataset2", H5T_NATIVE_LONG, orig_space_id, H5P_DEFAULT, dcpl_id, H5P_DEFAULT);
     CHECK_I(dset2_id, "H5Dcreate2");
-
-    if(close_reopen) {
-        /* If requested, close all open IDs and reopen them */
-        ret = H5Dclose(dset1_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Dclose(dset2_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Fclose(file_id);
-        CHECK_I(ret, "H5Fclose");
-
-        file_id = H5Fopen(FILENAME, H5F_ACC_RDWR, H5P_DEFAULT);
-        CHECK_I(file_id, "H5Fopen");
-        dset1_id = H5Dopen2(file_id, "dataset", H5P_DEFAULT);
-        CHECK_I(dset1_id, "H5Dopen2");
-        dset2_id = H5Dopen2(file_id, "dataset2", H5P_DEFAULT);
-        CHECK_I(dset2_id, "H5Dopen2");
-    }
+    if (close_reopen)
+        TSOHM_VDE_CLOSE_REOPEN_FILE_AND_DSETS(2);
 
     /* Create a third dataset with the same dataspace */
     dset3_id = H5Dcreate2(file_id, "dataset3", H5T_NATIVE_LONG, orig_space_id, H5P_DEFAULT, dcpl_id, H5P_DEFAULT);
     CHECK_I(dset3_id, "H5Dcreate2");
-
-    if(close_reopen) {
-        /* If requested, close all open IDs and reopen them */
-        ret = H5Dclose(dset1_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Dclose(dset2_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Dclose(dset3_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Fclose(file_id);
-        CHECK_I(ret, "H5Fclose");
-
-        file_id = H5Fopen(FILENAME, H5F_ACC_RDWR, H5P_DEFAULT);
-        CHECK_I(file_id, "H5Fopen");
-        dset1_id = H5Dopen2(file_id, "dataset", H5P_DEFAULT);
-        CHECK_I(dset1_id, "H5Dopen2");
-        dset2_id = H5Dopen2(file_id, "dataset2", H5P_DEFAULT);
-        CHECK_I(dset2_id, "H5Dopen2");
-        dset3_id = H5Dopen2(file_id, "dataset3", H5P_DEFAULT);
-        CHECK_I(dset3_id, "H5Dopen2");
-    }
+    if (close_reopen)
+        TSOHM_VDE_CLOSE_REOPEN_FILE_AND_DSETS(3);
 
     /* Extend the first dataset */
     ret = H5Dset_extent(dset1_id, dims2);
     CHECK_I(ret, "H5Dset_extent");
-    if(close_reopen) {
-        /* If requested, close all open IDs and reopen them */
-        ret = H5Dclose(dset1_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Dclose(dset2_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Dclose(dset3_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Fclose(file_id);
-        CHECK_I(ret, "H5Fclose");
-
-        file_id = H5Fopen(FILENAME, H5F_ACC_RDWR, H5P_DEFAULT);
-        CHECK_I(file_id, "H5Fopen");
-        dset1_id = H5Dopen2(file_id, "dataset", H5P_DEFAULT);
-        CHECK_I(dset1_id, "H5Dopen2");
-        dset2_id = H5Dopen2(file_id, "dataset2", H5P_DEFAULT);
-        CHECK_I(dset2_id, "H5Dopen2");
-        dset3_id = H5Dopen2(file_id, "dataset3", H5P_DEFAULT);
-        CHECK_I(dset3_id, "H5Dopen2");
-    }
+    if (close_reopen)
+        TSOHM_VDE_CLOSE_REOPEN_FILE_AND_DSETS(3);
 
-    /* Get the dataspaces from the datasets */
-    space1_id = H5Dget_space(dset1_id);
-    CHECK_I(space1_id, "H5Dget_space");
-    space2_id = H5Dget_space(dset2_id);
-    CHECK_I(space2_id, "H5Dget_space");
-    space3_id = H5Dget_space(dset3_id);
-    CHECK_I(space3_id, "H5Dget_space");
-
-    /* Verify the dataspaces */
-    ret = H5Sget_simple_extent_dims(space1_id, out_dims, out_maxdims);
-    CHECK_I(ret, "H5Sget_simple_extent_dims");
-    for(x=0; x<EXTEND_NDIMS; ++x) {
-        VERIFY(out_dims[x], dims2[x], "H5Sget_simple_extent_dims");
-        VERIFY(out_maxdims[x], max_dims[x], "H5Sget_simple_extent_dims");
-    }
-
-    ret = H5Sget_simple_extent_dims(space2_id, out_dims, out_maxdims);
-    CHECK_I(ret, "H5Sget_simple_extent_dims");
-    for(x=0; x<EXTEND_NDIMS; ++x) {
-        VERIFY(out_dims[x], dims1[x], "H5Sget_simple_extent_dims");
-        VERIFY(out_maxdims[x], max_dims[x], "H5Sget_simple_extent_dims");
-    }
-
-    ret = H5Sget_simple_extent_dims(space3_id, out_dims, out_maxdims);
-    CHECK_I(ret, "H5Sget_simple_extent_dims");
-    for(x=0; x<EXTEND_NDIMS; ++x) {
-        VERIFY(out_dims[x], dims1[x], "H5Sget_simple_extent_dims");
-        VERIFY(out_maxdims[x], max_dims[x], "H5Sget_simple_extent_dims");
-    }
-
-    /* Close all three dataspaces */
-    ret = H5Sclose(space1_id);
-    CHECK_I(ret, "H5Sclose");
-    ret = H5Sclose(space2_id);
-    CHECK_I(ret, "H5Sclose");
-    ret = H5Sclose(space3_id);
-    CHECK_I(ret, "H5Sclose");
+    space_dims[0] = dims2;
+    space_dims[1] = dims1;
+    space_dims[2] = dims1;
+    TSOHM_VDE_VERIFY_SPACES(space_dims);
 
     /* Extend the second dataset */
     ret = H5Dset_extent(dset2_id, dims2);
     CHECK_I(ret, "H5Dset_extent");
-    if(close_reopen) {
-        /* If requested, close all open IDs and reopen them */
-        ret = H5Dclose(dset1_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Dclose(dset2_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Dclose(dset3_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Fclose(file_id);
-        CHECK_I(ret, "H5Fclose");
-
-        file_id = H5Fopen(FILENAME, H5F_ACC_RDWR, H5P_DEFAULT);
-        CHECK_I(file_id, "H5Fopen");
-        dset1_id = H5Dopen2(file_id, "dataset", H5P_DEFAULT);
-        CHECK_I(dset1_id, "H5Dopen2");
-        dset2_id = H5Dopen2(file_id, "dataset2", H5P_DEFAULT);
-        CHECK_I(dset2_id, "H5Dopen2");
-        dset3_id = H5Dopen2(file_id, "dataset3", H5P_DEFAULT);
-        CHECK_I(dset3_id, "H5Dopen2");
-    }
-
-    /* Get the dataspaces from the datasets */
-    space1_id = H5Dget_space(dset1_id);
-    CHECK_I(space1_id, "H5Dget_space");
-    space2_id = H5Dget_space(dset2_id);
-    CHECK_I(space2_id, "H5Dget_space");
-    space3_id = H5Dget_space(dset3_id);
-    CHECK_I(space3_id, "H5Dget_space");
-
-    /* Verify the dataspaces */
-    ret = H5Sget_simple_extent_dims(space1_id, out_dims, out_maxdims);
-    CHECK_I(ret, "H5Sget_simple_extent_dims");
-    for(x=0; x<EXTEND_NDIMS; ++x) {
-        VERIFY(out_dims[x], dims2[x], "H5Sget_simple_extent_dims");
-        VERIFY(out_maxdims[x], max_dims[x], "H5Sget_simple_extent_dims");
-    }
-
-    ret = H5Sget_simple_extent_dims(space2_id, out_dims, out_maxdims);
-    CHECK_I(ret, "H5Sget_simple_extent_dims");
-    for(x=0; x<EXTEND_NDIMS; ++x) {
-        VERIFY(out_dims[x], dims2[x], "H5Sget_simple_extent_dims");
-        VERIFY(out_maxdims[x], max_dims[x], "H5Sget_simple_extent_dims");
-    }
+    if(close_reopen)
+        TSOHM_VDE_CLOSE_REOPEN_FILE_AND_DSETS(3);
 
-    ret = H5Sget_simple_extent_dims(space3_id, out_dims, out_maxdims);
-    CHECK_I(ret, "H5Sget_simple_extent_dims");
-    for(x=0; x<EXTEND_NDIMS; ++x) {
-        VERIFY(out_dims[x], dims1[x], "H5Sget_simple_extent_dims");
-        VERIFY(out_maxdims[x], max_dims[x], "H5Sget_simple_extent_dims");
-    }
-
-    /* Close all three dataspaces */
-    ret = H5Sclose(space1_id);
-    CHECK_I(ret, "H5Sclose");
-    ret = H5Sclose(space2_id);
-    CHECK_I(ret, "H5Sclose");
-    ret = H5Sclose(space3_id);
-    CHECK_I(ret, "H5Sclose");
+    space_dims[1] = dims2;
+    TSOHM_VDE_VERIFY_SPACES(space_dims);
 
     /* Extend the third dataset */
     ret = H5Dset_extent(dset3_id, dims2);
     CHECK_I(ret, "H5Dset_extent");
-    if(close_reopen) {
-        /* If requested, close all open IDs and reopen them */
-        ret = H5Dclose(dset1_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Dclose(dset2_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Dclose(dset3_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Fclose(file_id);
-        CHECK_I(ret, "H5Fclose");
-
-        file_id = H5Fopen(FILENAME, H5F_ACC_RDWR, H5P_DEFAULT);
-        CHECK_I(file_id, "H5Fopen");
-        dset1_id = H5Dopen2(file_id, "dataset", H5P_DEFAULT);
-        CHECK_I(dset1_id, "H5Dopen2");
-        dset2_id = H5Dopen2(file_id, "dataset2", H5P_DEFAULT);
-        CHECK_I(dset2_id, "H5Dopen2");
-        dset3_id = H5Dopen2(file_id, "dataset3", H5P_DEFAULT);
-        CHECK_I(dset3_id, "H5Dopen2");
-    }
-
-    /* Get the dataspaces from the datasets */
-    space1_id = H5Dget_space(dset1_id);
-    CHECK_I(space1_id, "H5Dget_space");
-    space2_id = H5Dget_space(dset2_id);
-    CHECK_I(space2_id, "H5Dget_space");
-    space3_id = H5Dget_space(dset3_id);
-    CHECK_I(space3_id, "H5Dget_space");
-
-    /* Verify the dataspaces */
-    ret = H5Sget_simple_extent_dims(space1_id, out_dims, out_maxdims);
-    CHECK_I(ret, "H5Sget_simple_extent_dims");
-    for(x=0; x<EXTEND_NDIMS; ++x) {
-        VERIFY(out_dims[x], dims2[x], "H5Sget_simple_extent_dims");
-        VERIFY(out_maxdims[x], max_dims[x], "H5Sget_simple_extent_dims");
-    }
-
-    ret = H5Sget_simple_extent_dims(space2_id, out_dims, out_maxdims);
-    CHECK_I(ret, "H5Sget_simple_extent_dims");
-    for(x=0; x<EXTEND_NDIMS; ++x) {
-        VERIFY(out_dims[x], dims2[x], "H5Sget_simple_extent_dims");
-        VERIFY(out_maxdims[x], max_dims[x], "H5Sget_simple_extent_dims");
-    }
-
-    ret = H5Sget_simple_extent_dims(space3_id, out_dims, out_maxdims);
-    CHECK_I(ret, "H5Sget_simple_extent_dims");
-    for(x=0; x<EXTEND_NDIMS; ++x) {
-        VERIFY(out_dims[x], dims2[x], "H5Sget_simple_extent_dims");
-        VERIFY(out_maxdims[x], max_dims[x], "H5Sget_simple_extent_dims");
-    }
+    if(close_reopen)
+        TSOHM_VDE_CLOSE_REOPEN_FILE_AND_DSETS(3);
 
-    /* Close all three dataspaces */
-    ret = H5Sclose(space1_id);
-    CHECK_I(ret, "H5Sclose");
-    ret = H5Sclose(space2_id);
-    CHECK_I(ret, "H5Sclose");
-    ret = H5Sclose(space3_id);
-    CHECK_I(ret, "H5Sclose");
+    space_dims[2] = dims2;
+    TSOHM_VDE_VERIFY_SPACES(space_dims);
 
     /* Close the datasets and file */
     ret = H5Dclose(dset1_id);
@@ -3523,164 +3511,44 @@ test_sohm_extend_dset_helper(hid_t fcpl_id, hbool_t close_reopen)
     CHECK_I(file_id, "H5Fcreate");
     dset1_id = H5Dcreate2(file_id, "dataset", H5T_NATIVE_LONG, orig_space_id, H5P_DEFAULT, dcpl_id, H5P_DEFAULT);
     CHECK_I(dset1_id, "H5Dcreate2");
-    if(close_reopen) {
-        /* If requested, close all open IDs and reopen them */
-        ret = H5Dclose(dset1_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Fclose(file_id);
-        CHECK_I(ret, "H5Fclose");
-
-        file_id = H5Fopen(FILENAME, H5F_ACC_RDWR, H5P_DEFAULT);
-        CHECK_I(file_id, "H5Fopen");
-        dset1_id = H5Dopen2(file_id, "dataset", H5P_DEFAULT);
-        CHECK_I(dset1_id, "H5Dopen2");
-    }
+    if (close_reopen)
+        TSOHM_VDE_CLOSE_REOPEN_FILE_AND_DSETS(1);
 
     /* Extend the first dataset */
     ret = H5Dset_extent(dset1_id, dims2);
     CHECK_I(ret, "H5Dset_extent");
-    if(close_reopen) {
-        /* If requested, close all open IDs and reopen them */
-        ret = H5Dclose(dset1_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Fclose(file_id);
-        CHECK_I(ret, "H5Fclose");
-
-        file_id = H5Fopen(FILENAME, H5F_ACC_RDWR, H5P_DEFAULT);
-        CHECK_I(file_id, "H5Fopen");
-        dset1_id = H5Dopen2(file_id, "dataset", H5P_DEFAULT);
-        CHECK_I(dset1_id, "H5Dopen2");
-    }
+    if (close_reopen)
+        TSOHM_VDE_CLOSE_REOPEN_FILE_AND_DSETS(1);
 
     /* Create the second dataset.  Its dataspace will be unshared and then
      * become shared when extended.
      */
     dset2_id = H5Dcreate2(file_id, "dataset2", H5T_NATIVE_LONG, orig_space_id, H5P_DEFAULT, dcpl_id, H5P_DEFAULT);
     CHECK_I(dset2_id, "H5Dcreate2");
-    if(close_reopen) {
-        /* If requested, close all open IDs and reopen them */
-        ret = H5Dclose(dset1_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Dclose(dset2_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Fclose(file_id);
-        CHECK_I(ret, "H5Fclose");
-
-        file_id = H5Fopen(FILENAME, H5F_ACC_RDWR, H5P_DEFAULT);
-        CHECK_I(file_id, "H5Fopen");
-        dset1_id = H5Dopen2(file_id, "dataset", H5P_DEFAULT);
-        CHECK_I(dset1_id, "H5Dopen2");
-        dset2_id = H5Dopen2(file_id, "dataset2", H5P_DEFAULT);
-        CHECK_I(dset2_id, "H5Dopen2");
-    }
+    if (close_reopen)
+        TSOHM_VDE_CLOSE_REOPEN_FILE_AND_DSETS(2);
 
     /* Extend the second dataset */
     ret = H5Dset_extent(dset2_id, dims2);
     CHECK_I(ret, "H5Dset_extent");
-    if(close_reopen) {
-        /* If requested, close all open IDs and reopen them */
-        ret = H5Dclose(dset1_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Dclose(dset2_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Fclose(file_id);
-        CHECK_I(ret, "H5Fclose");
-
-        file_id = H5Fopen(FILENAME, H5F_ACC_RDWR, H5P_DEFAULT);
-        CHECK_I(file_id, "H5Fopen");
-        dset1_id = H5Dopen2(file_id, "dataset", H5P_DEFAULT);
-        CHECK_I(dset1_id, "H5Dopen2");
-        dset2_id = H5Dopen2(file_id, "dataset2", H5P_DEFAULT);
-        CHECK_I(dset2_id, "H5Dopen2");
-    }
+    if (close_reopen)
+        TSOHM_VDE_CLOSE_REOPEN_FILE_AND_DSETS(2);
 
     /* Create the third dataset.  Its dataspace will be unshared and then
      * become shared when extended.
      */
     dset3_id = H5Dcreate2(file_id, "dataset3", H5T_NATIVE_LONG, orig_space_id, H5P_DEFAULT, dcpl_id, H5P_DEFAULT);
     CHECK_I(dset3_id, "H5Dcreate2");
-    if(close_reopen) {
-        /* If requested, close all open IDs and reopen them */
-        ret = H5Dclose(dset1_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Dclose(dset2_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Dclose(dset3_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Fclose(file_id);
-        CHECK_I(ret, "H5Fclose");
-
-        file_id = H5Fopen(FILENAME, H5F_ACC_RDWR, H5P_DEFAULT);
-        CHECK_I(file_id, "H5Fopen");
-        dset1_id = H5Dopen2(file_id, "dataset", H5P_DEFAULT);
-        CHECK_I(dset1_id, "H5Dopen2");
-        dset2_id = H5Dopen2(file_id, "dataset2", H5P_DEFAULT);
-        CHECK_I(dset2_id, "H5Dopen2");
-        dset3_id = H5Dopen2(file_id, "dataset3", H5P_DEFAULT);
-        CHECK_I(dset3_id, "H5Dopen2");
-    }
+    if(close_reopen)
+        TSOHM_VDE_CLOSE_REOPEN_FILE_AND_DSETS(3);
 
     /* Extend the third dataset */
     ret = H5Dset_extent(dset3_id, dims2);
     CHECK_I(ret, "H5Dset_extent");
-    if(close_reopen) {
-        /* If requested, close all open IDs and reopen them */
-        ret = H5Dclose(dset1_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Dclose(dset2_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Dclose(dset3_id);
-        CHECK_I(ret, "H5Dclose");
-        ret = H5Fclose(file_id);
-        CHECK_I(ret, "H5Fclose");
-
-        file_id = H5Fopen(FILENAME, H5F_ACC_RDWR, H5P_DEFAULT);
-        CHECK_I(file_id, "H5Fopen");
-        dset1_id = H5Dopen2(file_id, "dataset", H5P_DEFAULT);
-        CHECK_I(dset1_id, "H5Dopen2");
-        dset2_id = H5Dopen2(file_id, "dataset2", H5P_DEFAULT);
-        CHECK_I(dset2_id, "H5Dopen2");
-        dset3_id = H5Dopen2(file_id, "dataset3", H5P_DEFAULT);
-        CHECK_I(dset3_id, "H5Dopen2");
-    }
+    if(close_reopen)
+        TSOHM_VDE_CLOSE_REOPEN_FILE_AND_DSETS(3);
 
-    /* Get the dataspaces from the datasets */
-    space1_id = H5Dget_space(dset1_id);
-    CHECK_I(space1_id, "H5Dget_space");
-    space2_id = H5Dget_space(dset2_id);
-    CHECK_I(space2_id, "H5Dget_space");
-    space3_id = H5Dget_space(dset3_id);
-    CHECK_I(space3_id, "H5Dget_space");
-
-    /* Verify the dataspaces */
-    ret = H5Sget_simple_extent_dims(space1_id, out_dims, out_maxdims);
-    CHECK_I(ret, "H5Sget_simple_extent_dims");
-    for(x=0; x<EXTEND_NDIMS; ++x) {
-        VERIFY(out_dims[x], dims2[x], "H5Sget_simple_extent_dims");
-        VERIFY(out_maxdims[x], max_dims[x], "H5Sget_simple_extent_dims");
-    }
-
-    ret = H5Sget_simple_extent_dims(space2_id, out_dims, out_maxdims);
-    CHECK_I(ret, "H5Sget_simple_extent_dims");
-    for(x=0; x<EXTEND_NDIMS; ++x) {
-        VERIFY(out_dims[x], dims2[x], "H5Sget_simple_extent_dims");
-        VERIFY(out_maxdims[x], max_dims[x], "H5Sget_simple_extent_dims");
-    }
-
-    ret = H5Sget_simple_extent_dims(space3_id, out_dims, out_maxdims);
-    CHECK_I(ret, "H5Sget_simple_extent_dims");
-    for(x=0; x<EXTEND_NDIMS; ++x) {
-        VERIFY(out_dims[x], dims2[x], "H5Sget_simple_extent_dims");
-        VERIFY(out_maxdims[x], max_dims[x], "H5Sget_simple_extent_dims");
-    }
-
-    /* Close all three dataspaces */
-    ret = H5Sclose(space1_id);
-    CHECK_I(ret, "H5Sclose");
-    ret = H5Sclose(space2_id);
-    CHECK_I(ret, "H5Sclose");
-    ret = H5Sclose(space3_id);
-    CHECK_I(ret, "H5Sclose");
+    TSOHM_VDE_VERIFY_SPACES(space_dims);
 
     /* Close the datasets and file */
     ret = H5Dclose(dset1_id);
@@ -3698,12 +3566,15 @@ test_sohm_extend_dset_helper(hid_t fcpl_id, hbool_t close_reopen)
     ret = H5Pclose(dcpl_id);
     CHECK_I(ret, "H5Pclose");
 
-    /* Retrieve current # of errors */
+    /* Complain if this test generated errors */
     if(old_nerrs == GetTestNumErrs())
         return(0);
     else
         return(-1);
-} /* end test_sohm_extend_dset_helper() */
+/* macros are exclusive to this function */
+#undef TSOHM_VDE_CLOSE_REOPEN_FILE_AND_DSETS
+#undef TSOHM_VDE_VERIFY_SPACES
+} /* verify_dataset_extension */
 
 
 /*-------------------------------------------------------------------------
@@ -3726,74 +3597,71 @@ test_sohm_extend_dset(void)
     hid_t fcpl_id = -1;
     herr_t ret;
 
-    /* Create fcpl */
+    MESSAGE(5, ("Testing extending shared dataspaces\n"));
+
     fcpl_id = H5Pcreate(H5P_FILE_CREATE);
     CHECK_I(fcpl_id, "H5Pcreate");
-
-    /* Test extending datasets with different FCPLs */
     ret = H5Pset_shared_mesg_nindexes(fcpl_id, 1);
     CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
 
     /* No shared messages */
-    ret = test_sohm_extend_dset_helper(fcpl_id, FALSE);
-    CHECK_I(ret, "test_sohm_extend_dset_helper");
-    ret = test_sohm_extend_dset_helper(fcpl_id, TRUE);
-    CHECK_I(ret, "test_sohm_extend_dset_helper");
+    ret = verify_dataset_extension(fcpl_id, FALSE);
+    CHECK_I(ret, "verify_dataset_extension");
+    ret = verify_dataset_extension(fcpl_id, TRUE);
+    CHECK_I(ret, "verify_dataset_extension");
 
 
     /* Only dataspaces */
     ret = H5Pset_shared_mesg_index(fcpl_id, 0, H5O_SHMESG_SDSPACE_FLAG, 16);
     CHECK_I(ret, "H5Pset_shared_mesg_index");
 
-    ret = test_sohm_extend_dset_helper(fcpl_id, FALSE);
-    CHECK_I(ret, "test_sohm_extend_dset_helper");
-    ret = test_sohm_extend_dset_helper(fcpl_id, TRUE);
-    CHECK_I(ret, "test_sohm_extend_dset_helper");
+    ret = verify_dataset_extension(fcpl_id, FALSE);
+    CHECK_I(ret, "verify_dataset_extension");
+    ret = verify_dataset_extension(fcpl_id, TRUE);
+    CHECK_I(ret, "verify_dataset_extension");
 
     /* All messages */
-    ret = H5Pset_shared_mesg_nindexes(fcpl_id, 1);
-    CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
     ret = H5Pset_shared_mesg_index(fcpl_id, 0, H5O_SHMESG_ALL_FLAG, 16);
     CHECK_I(ret, "H5Pset_shared_mesg_index");
 
-    ret = test_sohm_extend_dset_helper(fcpl_id, FALSE);
-    CHECK_I(ret, "test_sohm_extend_dset_helper");
-    ret = test_sohm_extend_dset_helper(fcpl_id, TRUE);
-    CHECK_I(ret, "test_sohm_extend_dset_helper");
+    ret = verify_dataset_extension(fcpl_id, FALSE);
+    CHECK_I(ret, "verify_dataset_extension");
+    ret = verify_dataset_extension(fcpl_id, TRUE);
+    CHECK_I(ret, "verify_dataset_extension");
 
 
     /* All messages in lists */
     ret = H5Pset_shared_mesg_phase_change(fcpl_id, 100, 50);
     CHECK_I(ret, "H5Pset_shared_mesg_phase_change");
 
-    ret = test_sohm_extend_dset_helper(fcpl_id, FALSE);
-    CHECK_I(ret, "test_sohm_extend_dset_helper");
-    ret = test_sohm_extend_dset_helper(fcpl_id, TRUE);
-    CHECK_I(ret, "test_sohm_extend_dset_helper");
+    ret = verify_dataset_extension(fcpl_id, FALSE);
+    CHECK_I(ret, "verify_dataset_extension");
+    ret = verify_dataset_extension(fcpl_id, TRUE);
+    CHECK_I(ret, "verify_dataset_extension");
 
 
     /* All messages in lists converted to B-trees */
     ret = H5Pset_shared_mesg_phase_change(fcpl_id, 1, 0);
     CHECK_I(ret, "H5Pset_shared_mesg_phase_change");
 
-    ret = test_sohm_extend_dset_helper(fcpl_id, FALSE);
-    CHECK_I(ret, "test_sohm_extend_dset_helper");
-    ret = test_sohm_extend_dset_helper(fcpl_id, TRUE);
-    CHECK_I(ret, "test_sohm_extend_dset_helper");
+    ret = verify_dataset_extension(fcpl_id, FALSE);
+    CHECK_I(ret, "verify_dataset_extension");
+    ret = verify_dataset_extension(fcpl_id, TRUE);
+    CHECK_I(ret, "verify_dataset_extension");
 
 
     /* All messages in B-trees */
     ret = H5Pset_shared_mesg_phase_change(fcpl_id, 0, 0);
     CHECK_I(ret, "H5Pset_shared_mesg_phase_change");
 
-    ret = test_sohm_extend_dset_helper(fcpl_id, FALSE);
-    CHECK_I(ret, "test_sohm_extend_dset_helper");
-    ret = test_sohm_extend_dset_helper(fcpl_id, TRUE);
-    CHECK_I(ret, "test_sohm_extend_dset_helper");
+    ret = verify_dataset_extension(fcpl_id, FALSE);
+    CHECK_I(ret, "verify_dataset_extension");
+    ret = verify_dataset_extension(fcpl_id, TRUE);
+    CHECK_I(ret, "verify_dataset_extension");
 
     ret = H5Pclose(fcpl_id);
     CHECK_I(ret, "H5Pclose");
-}
+} /* test_sohm_extend_dset */
 
 
 /*-------------------------------------------------------------------------
@@ -3827,37 +3695,31 @@ test_sohm_external_dtype(void)
     unsigned x, i;
     herr_t ret;
 
+    MESSAGE(5, ("Testing shared external datatype\n"));
+
     fcpl = H5Pcreate(H5P_FILE_CREATE);
     CHECK_I(fcpl, "H5Pcreate");
-
-    /* Set up index values for sohm */
     ret = H5Pset_shared_mesg_nindexes(fcpl, TEST_NUM_INDEXES);
     CHECK_I(ret, "H5Pset_shared_mesg_nindexes");
-
-    for(x=0; x<TEST_NUM_INDEXES; ++x)
-    {
+    for(x=0; x<TEST_NUM_INDEXES; ++x) {
         ret = H5Pset_shared_mesg_index(fcpl, x, test_type_flags[x], test_minsizes[x]);
         CHECK_I(ret, "H5Pset_shared_mesg_index");
     }
-
     ret = H5Pset_shared_mesg_phase_change(fcpl, TEST_L2B, TEST_B2L);
     CHECK_I(ret, "H5Pset_shared_mesg_phase_change");
 
-    /* Create the data space */
     space = H5Screate_simple(2, dims, NULL);
     CHECK_I(space, "H5Screate_simple");
 
-    /* Create a data type for s1_t */
     s1_tid = H5Tcreate(H5T_COMPOUND, sizeof(s1_t));
     CHECK_I(s1_tid, "H5Tcreate");
-
     ret = H5Tinsert(s1_tid, "a", HOFFSET(s1_t,a), H5T_NATIVE_INT);
     CHECK_I(ret, "H5Tinsert");
-
     ret = H5Tinsert (s1_tid, "b", HOFFSET(s1_t,b), H5T_NATIVE_INT);
     CHECK_I(ret, "H5Tinsert");
 
-    /* Create the first file for this test */
+    /* Set up dataset in first file
+     */
     file1 = H5Fcreate(FILENAME_SRC, H5F_ACC_TRUNC, fcpl, H5P_DEFAULT);
     CHECK_I(file1, "H5Fcreate");
 
@@ -3866,7 +3728,6 @@ test_sohm_external_dtype(void)
     CHECK(ret, FAIL, "H5F__get_sohm_mesg_count_test");
     VERIFY(dmsg_count, 0, "H5F__get_sohm_mesg_count_test");
 
-    /* Create data set */
     dataset1 = H5Dcreate2(file1, "dataset_1", s1_tid, space, H5P_DEFAULT, H5P_DEFAULT,
         H5P_DEFAULT);
     CHECK_I(dataset1, "H5Dcreate2");
@@ -3876,26 +3737,26 @@ test_sohm_external_dtype(void)
     CHECK(ret, FAIL, "H5F__get_sohm_mesg_count_test");
     VERIFY(dmsg_count, 1, "H5F__get_sohm_mesg_count_test");
 
-    /* Retieve the dataset's datatype */
     dset1_tid = H5Dget_type(dataset1);
     CHECK_I(dset1_tid, "H5Dget_type");
 
     /* Allocate space and initialize data */
     orig = (s1_t*)HDmalloc(NX * NY * sizeof(s1_t));
+    if (orig == NULL)
+        CHECK_I(-1, "HDmalloc");
     for(i=0; i<NX*NY; i++) {
         s_ptr = (s1_t*)orig + i;
         s_ptr->a = (int)(i * 3 + 1);
         s_ptr->b = (int)(i * 3 + 2);
     }
 
-    /* Write the data to the dataset1 */
     ret = H5Dwrite(dataset1, s1_tid, H5S_ALL, H5S_ALL, H5P_DEFAULT, orig);
     CHECK_I(ret, "H5Dwrite");
-
     ret = H5Dclose(dataset1);
     CHECK_I(ret, "H5Dclose");
 
-    /* Create the second file for this test */
+    /* Create dataset in second file using datatype from dataset in the first file
+     */
     file2 = H5Fcreate(FILENAME_DST, H5F_ACC_TRUNC, fcpl, H5P_DEFAULT);
     CHECK_I(file2, "H5Fcreate");
 
@@ -3904,7 +3765,6 @@ test_sohm_external_dtype(void)
     CHECK(ret, FAIL, "H5F__get_sohm_mesg_count_test");
     VERIFY(dmsg_count, 0, "H5F__get_sohm_mesg_count_test");
 
-    /* Create a data set using the datatype of the dataset in the first file. */
     dataset2 = H5Dcreate2(file2, "dataset_2", dset1_tid, space, H5P_DEFAULT, H5P_DEFAULT,
         H5P_DEFAULT);
     CHECK_I(dataset2, "H5Dcreate2");
@@ -3914,54 +3774,44 @@ test_sohm_external_dtype(void)
     CHECK(ret, FAIL, "H5F__get_sohm_mesg_count_test");
     VERIFY(dmsg_count, 1, "H5F__get_sohm_mesg_count_test");
 
-    /* Write the data to the dataset2 */
     ret = H5Dwrite(dataset2, s1_tid, H5S_ALL, H5S_ALL, H5P_DEFAULT, orig);
     CHECK_I(ret, "H5Dwrite");
 
+    /* Close references to the first file */
     ret = H5Dclose(dataset2);
     CHECK_I(ret, "H5Dclose");
-
-    /* Close file 1 and the dataset's datatype in file 1.  Verify that the datatype in
-     * file 2 is still accessible. */
     ret = H5Tclose(dset1_tid);
     CHECK_I(ret, "H5Tclose");
-
     ret = H5Fclose(file1);
     CHECK_I(ret, "H5Fclose");
 
-    /* Open the dataset in file 2 */
+    /* Verify that datatype details are still accessible by second file
+     */
     dataset2 = H5Dopen2(file2, "dataset_2", H5P_DEFAULT);
     CHECK_I(dataset2, "H5Dopen2");
 
-    /* Retieve the dataset's datatype */
     dset2_tid = H5Dget_type(dataset2);
     CHECK_I(dset2_tid, "H5Dget_type");
 
-    /* Verify the datatype is compound */
     dtype_class = H5Tget_class(dset2_tid);
     VERIFY(dtype_class, H5T_COMPOUND, "H5Tget_class");
 
+    /* Cleanup
+     */
     ret = H5Tclose(dset2_tid);
     CHECK_I(ret, "H5Tclose");
-
     ret = H5Dclose(dataset2);
     CHECK_I(ret, "H5Dclose");
-
-    /* Finishing test and release resources */
     ret = H5Sclose(space);
     CHECK_I(ret, "H5Sclose");
-
     ret = H5Tclose(s1_tid);
     CHECK_I(ret, "H5Tclose");
-
     ret = H5Pclose(fcpl);
     CHECK_I(ret, "H5Pclose");
-
     ret = H5Fclose(file2);
     CHECK_I(ret, "H5Fclose");
-
     HDfree(orig);
-}
+} /* test_sohm_external_dtype */
 
 
 /****************************************************************
@@ -3972,11 +3822,14 @@ test_sohm_external_dtype(void)
 void
 test_sohm(void)
 {
-    /* Output message about test being performed */
     MESSAGE(5, ("Testing Shared Object Header Messages\n"));
 
-    test_sohm_fcpl();		/* Test SOHMs and file creation plists */
+    test_sohm_fcpl();           /* Test SOHMs and file creation plists */
+    test_sohm_fcpl_errors();    /* Bogus H5P* calls for SOHMs */
     test_sohm_size1();          /* Tests the sizes of files with one SOHM */
+#if 0 /* TODO: REVEALS BUG TO BE FIXED - SEE JIRA HDFFV-10645 */
+    test_sohm_size_consistency_open_create();
+#endif /* Jira HDFFV-10645 */
     test_sohm_attrs();          /* Tests shared messages in attributes */
     test_sohm_size2(0);         /* Tests the sizes of files with multiple SOHMs */
     test_sohm_size2(1);         /* Tests the sizes of files with multiple
@@ -3989,17 +3842,17 @@ test_sohm(void)
 
     test_sohm_extend_dset();    /* Test extending shared datasets */
     test_sohm_external_dtype(); /* Test using datatype in another file */
-} /* test_sohm() */
+} /* test_sohm */
 
 
 /*-------------------------------------------------------------------------
- * Function:	cleanup_sohm
+ * Function:    cleanup_sohm
  *
- * Purpose:	Cleanup temporary test files
+ * Purpose:     Cleanup temporary test files
  *
- * Return:	none
+ * Return:      none
  *
- * Programmer:	James Laird
+ * Programmer:  James Laird
  *              October 9, 2006
  *
  * Modifications:
@@ -4012,5 +3865,5 @@ cleanup_sohm(void)
     remove(FILENAME);
     remove(FILENAME_SRC);
     remove(FILENAME_DST);
-}
+} /* cleanup_sohm */
 
diff --git a/test/vol_plugin.c b/test/vol_plugin.c
new file mode 100644
index 0000000..236a67e
--- /dev/null
+++ b/test/vol_plugin.c
@@ -0,0 +1,291 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*
+ * Purpose:     Tests basic VOL plugin operations (registration, etc.).
+ *              Uses the null VOL connector (built with the testing code)
+ *              which is loaded as a dynamic plugin.
+ *
+ * TO DO:       Adapt the null VOL connector to do something interesting with
+ *              the property list.
+ */
+
+#include "h5test.h"
+
+#include "null_vol_connector.h"
+
+
+/*-------------------------------------------------------------------------
+ * Function:    test_registration_by_value()
+ *
+ * Purpose:     Tests if we can load, register, and close a VOL
+ *              connector by value.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+test_registration_by_value(void)
+{
+    htri_t  is_registered   = FAIL;
+    hid_t   vol_id          = H5I_INVALID_HID;
+
+    TESTING("VOL registration by value");
+
+    /* The null VOL connector should not be registered at the start of the test */
+    if((is_registered = H5VLis_connector_registered(NULL_VOL_CONNECTOR_NAME)) < 0)
+        TEST_ERROR;
+    if(TRUE == is_registered)
+        FAIL_PUTS_ERROR("NULL VOL connector is inappropriately registered");
+
+    /* Register the connector by value */
+    if((vol_id = H5VLregister_connector_by_value(NULL_VOL_CONNECTOR_VALUE, H5P_DEFAULT)) < 0)
+        TEST_ERROR;
+
+    /* The connector should be registered now */
+    if((is_registered = H5VLis_connector_registered(NULL_VOL_CONNECTOR_NAME)) < 0)
+        TEST_ERROR;
+    if(FALSE == is_registered)
+        FAIL_PUTS_ERROR("NULL VOL connector was not registered");
+
+    /* Unregister the connector */
+    if(H5VLunregister_connector(vol_id) < 0)
+        TEST_ERROR;
+
+    /* The connector should not be registered now */
+    if((is_registered = H5VLis_connector_registered(NULL_VOL_CONNECTOR_NAME)) < 0)
+        TEST_ERROR;
+    if(TRUE == is_registered)
+        FAIL_PUTS_ERROR("NULL VOL connector is inappropriately registered");
+
+    PASSED();
+    return SUCCEED;
+
+error:
+    H5E_BEGIN_TRY {
+        H5VLunregister_connector(vol_id);
+    } H5E_END_TRY;
+    return FAIL;
+
+} /* end test_registration_by_value() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    test_registration_by_name()
+ *
+ * Purpose:     Tests if we can load, register, and close a VOL
+ *              connector by name.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+test_registration_by_name(void)
+{
+    htri_t  is_registered   = FAIL;
+    hid_t   vol_id          = H5I_INVALID_HID;
+
+    TESTING("VOL registration by name");
+
+    /* The null VOL connector should not be registered at the start of the test */
+    if((is_registered = H5VLis_connector_registered(NULL_VOL_CONNECTOR_NAME)) < 0)
+        TEST_ERROR;
+    if(TRUE == is_registered)
+        FAIL_PUTS_ERROR("NULL VOL connector is inappropriately registered");
+
+    /* Register the connector by name */
+    if((vol_id = H5VLregister_connector_by_name(NULL_VOL_CONNECTOR_NAME, H5P_DEFAULT)) < 0)
+        TEST_ERROR;
+
+    /* The connector should be registered now */
+    if((is_registered = H5VLis_connector_registered(NULL_VOL_CONNECTOR_NAME)) < 0)
+        TEST_ERROR;
+    if(FALSE == is_registered)
+        FAIL_PUTS_ERROR("NULL VOL connector was not registered");
+
+    /* Unregister the connector */
+    if(H5VLunregister_connector(vol_id) < 0)
+        TEST_ERROR;
+
+    /* The connector should not be registered now */
+    if((is_registered = H5VLis_connector_registered(NULL_VOL_CONNECTOR_NAME)) < 0)
+        TEST_ERROR;
+    if(TRUE == is_registered)
+        FAIL_PUTS_ERROR("NULL VOL connector is inappropriately registered");
+
+    PASSED();
+    return SUCCEED;
+
+error:
+    H5E_BEGIN_TRY {
+        H5VLunregister_connector(vol_id);
+    } H5E_END_TRY;
+    return FAIL;
+
+} /* end test_registration_by_name() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    test_multiple_registration()
+ *
+ * Purpose:     Tests if we can register a VOL connector multiple times.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+#define N_REGISTRATIONS 10
+static herr_t
+test_multiple_registration(void)
+{
+    htri_t  is_registered   = FAIL;
+    hid_t   vol_ids[N_REGISTRATIONS];
+    int     i;
+
+    TESTING("registering a VOL connector multiple times");
+
+    /* The null VOL connector should not be registered at the start of the test */
+    if((is_registered = H5VLis_connector_registered(NULL_VOL_CONNECTOR_NAME)) < 0)
+        TEST_ERROR;
+    if(TRUE == is_registered)
+        FAIL_PUTS_ERROR("NULL VOL connector is inappropriately registered");
+
+    /* Register the connector multiple times */
+    for(i = 0; i < N_REGISTRATIONS; i++) {
+        if((vol_ids[i] = H5VLregister_connector_by_name(NULL_VOL_CONNECTOR_NAME, H5P_DEFAULT)) < 0)
+            TEST_ERROR;
+    }
+
+    /* The connector should be registered now */
+    if((is_registered = H5VLis_connector_registered(NULL_VOL_CONNECTOR_NAME)) < 0)
+        TEST_ERROR;
+    if(FALSE == is_registered)
+        FAIL_PUTS_ERROR("NULL VOL connector was not registered");
+
+    /* Unregister the connector */
+    for(i = 0; i < N_REGISTRATIONS; i++) {
+        if(H5VLunregister_connector(vol_ids[i]) < 0)
+            TEST_ERROR;
+        /* Also test close on some of the IDs. This call currently works
+         * identically to unregister.
+         */
+        i++;
+        if(H5VLclose(vol_ids[i]) < 0)
+            TEST_ERROR;
+    }
+
+    /* The connector should not be registered now */
+    if((is_registered = H5VLis_connector_registered(NULL_VOL_CONNECTOR_NAME)) < 0)
+        TEST_ERROR;
+    if(TRUE == is_registered)
+        FAIL_PUTS_ERROR("NULL VOL connector is inappropriately registered");
+
+    PASSED();
+    return SUCCEED;
+
+error:
+    H5E_BEGIN_TRY {
+        for(i = 0; i < N_REGISTRATIONS; i++)
+            H5VLunregister_connector(vol_ids[i]);
+    } H5E_END_TRY;
+    return FAIL;
+
+} /* end test_multiple_registration() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    test_getters()
+ *
+ * Purpose:     Tests H5VL getters
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+test_getters(void)
+{
+    htri_t  is_registered   = FAIL;
+    hid_t   vol_id          = H5I_INVALID_HID;
+    hid_t   vol_id_out      = H5I_INVALID_HID;
+
+    TESTING("VOL getters");
+
+    /* The null VOL connector should not be registered at the start of the test */
+    if((is_registered = H5VLis_connector_registered(NULL_VOL_CONNECTOR_NAME)) < 0)
+        TEST_ERROR;
+    if(TRUE == is_registered)
+        FAIL_PUTS_ERROR("NULL VOL connector is inappropriately registered");
+
+    /* Register the connector by name */
+    if((vol_id = H5VLregister_connector_by_name(NULL_VOL_CONNECTOR_NAME, H5P_DEFAULT)) < 0)
+        TEST_ERROR;
+
+    /* Get the connector's ID */
+    if((vol_id_out = H5VLget_connector_id(NULL_VOL_CONNECTOR_NAME)) < 0)
+        TEST_ERROR;
+    if(vol_id != vol_id_out)
+        FAIL_PUTS_ERROR("VOL connector IDs don't match");
+
+    /* Unregister the connector */
+    if(H5VLunregister_connector(vol_id) < 0)
+        TEST_ERROR;
+
+    PASSED();
+    return SUCCEED;
+
+error:
+    H5E_BEGIN_TRY {
+        H5VLunregister_connector(vol_id);
+    } H5E_END_TRY;
+    return FAIL;
+
+} /* end test_getters() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    main
+ *
+ * Purpose:     Tests VOL connector plugin operations
+ *
+ * Return:      EXIT_SUCCESS/EXIT_FAILURE
+ *
+ *-------------------------------------------------------------------------
+ */
+int
+main(void)
+{
+    int nerrors = 0;
+
+    h5_reset();
+
+    HDputs("Testing VOL connector plugin functionality.");
+
+    nerrors += test_registration_by_name() < 0          ? 1 : 0;
+    nerrors += test_registration_by_value() < 0         ? 1 : 0;
+    nerrors += test_multiple_registration() < 0         ? 1 : 0;
+    nerrors += test_getters() < 0                       ? 1 : 0;
+
+    if(nerrors) {
+        HDprintf("***** %d VOL connector plugin TEST%s FAILED! *****\n",
+            nerrors, nerrors > 1 ? "S" : "");
+        HDexit(EXIT_FAILURE);
+    }
+
+    HDputs("All VOL connector plugin tests passed.");
+
+    HDexit(EXIT_SUCCESS);
+
+} /* end main() */
+
diff --git a/testpar/CMakeTests.cmake b/testpar/CMakeTests.cmake
index 87470f3..dffb813 100644
--- a/testpar/CMakeTests.cmake
+++ b/testpar/CMakeTests.cmake
@@ -27,47 +27,12 @@ endforeach ()
 set_property (TEST TEST_PAR_t_pflush1 PROPERTY PASS_REGULAR_EXPRESSION "PASSED")
 set_tests_properties (TEST_PAR_t_pflush2 PROPERTIES DEPENDS TEST_PAR_t_pflush1)
 
-if (HDF5_TEST_VFD)
-
-  set (VFD_LIST
-      sec2
-      stdio
-      core
-      split
-      multi
-      family
-  )
-
-  set (H5P_VFD_TESTS
-      t_pflush1
-      t_pflush2
-  )
-
-  if (DIRECT_VFD)
-    set (VFD_LIST ${VFD_LIST} direct)
-  endif ()
-
-  macro (ADD_VFD_TEST vfdname resultcode)
-    if (NOT HDF5_ENABLE_USING_MEMCHECKER)
-      foreach (test ${H5P_VFD_TESTS})
-        add_test (
-          NAME TEST_PAR_VFD-${vfdname}-${test}
-          COMMAND "${CMAKE_COMMAND}"
-              -D "TEST_PROGRAM=$<TARGET_FILE:${test}>"
-              -D "TEST_ARGS:STRING="
-              -D "TEST_VFD:STRING=${vfdname}"
-              -D "TEST_EXPECT=${resultcode}"
-              -D "TEST_OUTPUT=${test}"
-              -D "TEST_FOLDER=${PROJECT_BINARY_DIR}"
-              -P "${HDF_RESOURCES_DIR}/vfdTest.cmake"
-        )
-      endforeach ()
-    endif ()
-  endmacro ()
-
-  # Run test with different Virtual File Driver
-  foreach (vfd ${VFD_LIST})
-    ADD_VFD_TEST (${vfd} 0)
-  endforeach ()
+##############################################################################
+##############################################################################
+###                         V F D   T E S T S                              ###
+##############################################################################
+##############################################################################
 
+if (HDF5_TEST_VFD)
+  include (CMakeVFDTests.cmake)
 endif ()
diff --git a/testpar/CMakeVFDTests.cmake b/testpar/CMakeVFDTests.cmake
new file mode 100644
index 0000000..b6b065f
--- /dev/null
+++ b/testpar/CMakeVFDTests.cmake
@@ -0,0 +1,57 @@
+#
+# Copyright by The HDF Group.
+# All rights reserved.
+#
+# This file is part of HDF5.  The full HDF5 copyright notice, including
+# terms governing use, modification, and redistribution, is contained in
+# the COPYING file, which can be found at the root of the source code
+# distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.
+# If you do not have access to either file, you may request a copy from
+# help@hdfgroup.org.
+#
+
+##############################################################################
+##############################################################################
+###           T E S T I N G                                                ###
+##############################################################################
+##############################################################################
+  set (VFD_LIST
+      sec2
+      stdio
+      core
+      split
+      multi
+      family
+  )
+
+  set (H5P_VFD_TESTS
+      t_pflush1
+      t_pflush2
+  )
+
+  if (DIRECT_VFD)
+    set (VFD_LIST ${VFD_LIST} direct)
+  endif ()
+
+  macro (ADD_VFD_TEST vfdname resultcode)
+    if (NOT HDF5_ENABLE_USING_MEMCHECKER)
+      foreach (test ${H5P_VFD_TESTS})
+        add_test (
+          NAME TEST_PAR_VFD-${vfdname}-${test}
+          COMMAND "${CMAKE_COMMAND}"
+              -D "TEST_PROGRAM=$<TARGET_FILE:${test}>"
+              -D "TEST_ARGS:STRING="
+              -D "TEST_VFD:STRING=${vfdname}"
+              -D "TEST_EXPECT=${resultcode}"
+              -D "TEST_OUTPUT=${test}"
+              -D "TEST_FOLDER=${PROJECT_BINARY_DIR}"
+              -P "${HDF_RESOURCES_DIR}/vfdTest.cmake"
+        )
+      endforeach ()
+    endif ()
+  endmacro ()
+
+  # Run test with different Virtual File Driver
+  foreach (vfd ${VFD_LIST})
+    ADD_VFD_TEST (${vfd} 0)
+  endforeach ()
diff --git a/testpar/Makefile.am b/testpar/Makefile.am
index 7262ca6..a11099d 100644
--- a/testpar/Makefile.am
+++ b/testpar/Makefile.am
@@ -21,11 +21,19 @@ include $(top_srcdir)/config/commence.am
 
 AM_CPPFLAGS+=-I$(top_srcdir)/src -I$(top_srcdir)/test
 
+# Test scripts--
+#       testpflush.sh:
+TEST_SCRIPT_PARA = testpflush.sh
+SCRIPT_DEPEND = t_pflush1$(EXEEXT) t_pflush2$(EXEEXT) 
+
+check_SCRIPTS = $(TEST_SCRIPT_PARA)
+
 # Test programs.  These are our main targets.
 #
-TEST_PROG_PARA=t_mpi t_bigio testphdf5 t_cache t_cache_image t_pflush1 t_pflush2 t_pread t_pshutdown t_prestart t_init_term t_shapesame t_filters_parallel
+TEST_PROG_PARA=t_mpi t_bigio testphdf5 t_cache t_cache_image t_pread t_pshutdown t_prestart t_init_term t_shapesame t_filters_parallel
 
-check_PROGRAMS = $(TEST_PROG_PARA)
+# t_pflush1 and t_pflush2 are used by testpflush.sh
+check_PROGRAMS = $(TEST_PROG_PARA) t_pflush1 t_pflush2
 
 testphdf5_SOURCES=testphdf5.c t_dset.c t_file.c t_file_image.c t_mdset.c \
 	t_ph5basic.c t_coll_chunk.c t_span_tree.c t_chunk_alloc.c t_filter_read.c \
diff --git a/testpar/t_cache.c b/testpar/t_cache.c
index da83884..7488728 100644
--- a/testpar/t_cache.c
+++ b/testpar/t_cache.c
@@ -467,9 +467,7 @@ static void lock_and_unlock_random_entry(H5F_t * file_ptr,
 static void lock_entry(H5F_t * file_ptr, int32_t idx);
 static void mark_entry_dirty(int32_t idx);
 static void pin_entry(H5F_t * file_ptr, int32_t idx, hbool_t global, hbool_t dirty);
-#ifdef H5_METADATA_TRACE_FILE
 static void pin_protected_entry(int32_t idx, hbool_t global);
-#endif /* H5_METADATA_TRACE_FILE */
 static void move_entry(H5F_t * file_ptr, int32_t old_idx, int32_t new_idx);
 static hbool_t reset_server_counts(void);
 static void resize_entry(int32_t idx, size_t  new_size);
@@ -3693,7 +3691,6 @@ pin_entry(H5F_t * file_ptr,
 
 } /* pin_entry() */
 
-#ifdef H5_METADATA_TRACE_FILE
 
 /*****************************************************************************
  * Function:    pin_protected_entry()
@@ -3762,7 +3759,6 @@ pin_protected_entry(int32_t idx,
     return;
 
 } /* pin_protected_entry() */
-#endif /* H5_METADATA_TRACE_FILE */
 
 
 /*****************************************************************************
@@ -6809,8 +6805,6 @@ smoke_check_5(int metadata_write_strategy)
  *                    - H5AC_expunge_entry()
  *                    - H5AC_resize_entry()
  *
- *              This test is skipped if H5_METADATA_TRACE_FILE is undefined.
- *
  * Return:    Success:    TRUE
  *
  *        Failure:    FALSE
@@ -6823,63 +6817,63 @@ trace_file_check(int metadata_write_strategy)
 {
     hbool_t success = TRUE;
 
-#ifdef H5_METADATA_TRACE_FILE
-
     const char *((* expected_output)[]) = NULL;
     const char * expected_output_0[] =
     {
       "### HDF5 metadata cache trace file version 1 ###\n",
-      "H5AC_set_cache_auto_resize_config 1 0 1 0 \"t_cache_trace.txt\" 1 0 2097152 0.300000 33554432 1048576 50000 1 0.900000 2.000000 1 1.000000 0.250000 1 4194304 3 0.999000 0.900000 1 1048576 3 1 0.100000 262144 0 0\n",
-      "H5AC_insert_entry 0x400 27 0x0 2 0\n",
-      "H5AC_insert_entry 0x402 27 0x0 2 0\n",
-      "H5AC_insert_entry 0x404 27 0x0 4 0\n",
-      "H5AC_insert_entry 0x408 27 0x0 6 0\n",
-      "H5AC_protect 0x400 27 0x0 2 1\n",
-      "H5AC_mark_entry_dirty 0x400 0\n",
-      "H5AC_unprotect 0x400 27 0x0 0\n",
-      "H5AC_protect 0x402 27 0x0 2 1\n",
-      "H5AC_pin_protected_entry 0x402 0\n",
-      "H5AC_unprotect 0x402 27 0x0 0\n",
-      "H5AC_unpin_entry 0x402 0\n",
-      "H5AC_expunge_entry 0x402 27 0\n",
-      "H5AC_protect 0x404 27 0x0 4 1\n",
-      "H5AC_pin_protected_entry 0x404 0\n",
-      "H5AC_unprotect 0x404 27 0x0 0\n",
-      "H5AC_mark_entry_dirty 0x404 0\n",
-      "H5AC_resize_entry 0x404 2 0\n",
-      "H5AC_resize_entry 0x404 4 0\n",
-      "H5AC_unpin_entry 0x404 0\n",
-      "H5AC_move_entry 0x400 0x8e65 27 0\n",
-      "H5AC_move_entry 0x8e65 0x400 27 0\n",
-      "H5AC_flush 0\n",
+      "H5AC_set_cache_auto_resize_config",
+      "H5AC_insert_entry",
+      "H5AC_insert_entry",
+      "H5AC_insert_entry",
+      "H5AC_insert_entry",
+      "H5AC_protect",
+      "H5AC_mark_entry_dirty",
+      "H5AC_unprotect",
+      "H5AC_protect",
+      "H5AC_pin_protected_entry",
+      "H5AC_unprotect",
+      "H5AC_unpin_entry",
+      "H5AC_expunge_entry",
+      "H5AC_protect",
+      "H5AC_pin_protected_entry",
+      "H5AC_unprotect",
+      "H5AC_mark_entry_dirty",
+      "H5AC_resize_entry",
+      "H5AC_resize_entry",
+      "H5AC_unpin_entry",
+      "H5AC_move_entry",
+      "H5AC_move_entry",
+      "H5AC_flush",
+      "H5AC_flush",
       NULL
     };
     const char * expected_output_1[] =
     {
       "### HDF5 metadata cache trace file version 1 ###\n",
-      "H5AC_set_cache_auto_resize_config 1 0 1 0 \"t_cache_trace.txt\" 1 0 2097152 0.300000 33554432 1048576 50000 1 0.900000 2.000000 1 1.000000 0.250000 1 4194304 3 0.999000 0.900000 1 1048576 3 1 0.100000 262144 1 0\n",
-      "H5AC_insert_entry 0x400 27 0x0 2 0\n",
-      "H5AC_insert_entry 0x402 27 0x0 2 0\n",
-      "H5AC_insert_entry 0x404 27 0x0 4 0\n",
-      "H5AC_insert_entry 0x408 27 0x0 6 0\n",
-      "H5AC_protect 0x400 27 0x0 2 1\n",
-      "H5AC_mark_entry_dirty 0x400 0\n",
-      "H5AC_unprotect 0x400 27 0x0 0\n",
-      "H5AC_protect 0x402 27 0x0 2 1\n",
-      "H5AC_pin_protected_entry 0x402 0\n",
-      "H5AC_unprotect 0x402 27 0x0 0\n",
-      "H5AC_unpin_entry 0x402 0\n",
-      "H5AC_expunge_entry 0x402 27 0\n",
-      "H5AC_protect 0x404 27 0x0 4 1\n",
-      "H5AC_pin_protected_entry 0x404 0\n",
-      "H5AC_unprotect 0x404 27 0x0 0\n",
-      "H5AC_mark_entry_dirty 0x404 0\n",
-      "H5AC_resize_entry 0x404 2 0\n",
-      "H5AC_resize_entry 0x404 4 0\n",
-      "H5AC_unpin_entry 0x404 0\n",
-      "H5AC_move_entry 0x400 0x8e65 27 0\n",
-      "H5AC_move_entry 0x8e65 0x400 27 0\n",
-      "H5AC_flush 0\n",
+      "H5AC_set_cache_auto_resize_config",
+      "H5AC_insert_entry",
+      "H5AC_insert_entry",
+      "H5AC_insert_entry",
+      "H5AC_insert_entry",
+      "H5AC_protect",
+      "H5AC_mark_entry_dirty",
+      "H5AC_unprotect",
+      "H5AC_protect",
+      "H5AC_pin_protected_entry",
+      "H5AC_unprotect",
+      "H5AC_unpin_entry",
+      "H5AC_expunge_entry",
+      "H5AC_protect",
+      "H5AC_pin_protected_entry",
+      "H5AC_unprotect",
+      "H5AC_mark_entry_dirty",
+      "H5AC_resize_entry",
+      "H5AC_resize_entry",
+      "H5AC_unpin_entry",
+      "H5AC_move_entry",
+      "H5AC_move_entry",
+      "H5AC_flush",
+      "H5AC_flush",
       NULL
     };
     char buffer[256];
@@ -6887,8 +6881,8 @@ trace_file_check(int metadata_write_strategy)
     hbool_t done = FALSE;
     int i;
     int max_nerrors;
-    int expected_line_len;
-    int actual_line_len;
+    size_t expected_line_len;
+    size_t actual_line_len;
     hid_t fid = -1;
     H5F_t * file_ptr = NULL;
     H5C_t * cache_ptr = NULL;
@@ -6896,188 +6890,151 @@ trace_file_check(int metadata_write_strategy)
     H5AC_cache_config_t config;
     struct mssg_t mssg;
 
-#endif /* H5_METADATA_TRACE_FILE */
 
-    switch ( metadata_write_strategy ) {
+    switch(metadata_write_strategy) {
+
+        case H5AC_METADATA_WRITE_STRATEGY__PROCESS_0_ONLY:
 
-    case H5AC_METADATA_WRITE_STRATEGY__PROCESS_0_ONLY:
-#ifdef H5_METADATA_TRACE_FILE
             expected_output = &expected_output_0;
-#endif /* H5_METADATA_TRACE_FILE */
-            if ( world_mpi_rank == 0 ) {
-            TESTING(
-            "trace file collection -- process 0 only md write strategy");
-            }
-        break;
 
-    case H5AC_METADATA_WRITE_STRATEGY__DISTRIBUTED:
-#ifdef H5_METADATA_TRACE_FILE
+            if(world_mpi_rank == 0)
+                TESTING("trace file collection -- process 0 only md write strategy");
+            break;
+
+        case H5AC_METADATA_WRITE_STRATEGY__DISTRIBUTED:
+
             expected_output = &expected_output_1;
-#endif /* H5_METADATA_TRACE_FILE */
-            if ( world_mpi_rank == 0 ) {
-            TESTING(
-            "trace file collection -- distributed md write strategy");
-            }
-        break;
+
+            if(world_mpi_rank == 0)
+                TESTING("trace file collection -- distributed md write strategy");
+            break;
 
         default:
-#ifdef H5_METADATA_TRACE_FILE
+
             /* this will almost certainly cause a failure, but it keeps us
              * from de-referenceing a NULL pointer.
              */
             expected_output = &expected_output_0;
-#endif /* H5_METADATA_TRACE_FILE */
-            if ( world_mpi_rank == 0 ) {
-            TESTING("trace file collection -- unknown md write strategy");
-            }
-        break;
-    }
 
-#ifdef H5_METADATA_TRACE_FILE
+            if(world_mpi_rank == 0)
+                TESTING("trace file collection -- unknown md write strategy");
+            break;
+    } /* end switch */
+
 
     nerrors = 0;
     init_data();
     reset_stats();
 
-    if ( world_mpi_rank == world_server_mpi_rank ) {
+    if(world_mpi_rank == world_server_mpi_rank) {
 
-    if ( ! server_main() ) {
+        if(!server_main()) {
 
             /* some error occured in the server -- report failure */
             nerrors++;
-            if ( verbose ) {
-        HDfprintf(stdout, "%d:%s: server_main() failed.\n",
-                          world_mpi_rank, FUNC);
-            }
+            if ( verbose )
+                HDfprintf(stdout, "%d:%s: server_main() failed.\n", world_mpi_rank, FUNC);
         }
     }
-    else /* run the clients */
-    {
+    else {
+        /* run the clients */
 
-        if ( ! setup_cache_for_test(&fid, &file_ptr, &cache_ptr,
-                                    metadata_write_strategy) ) {
+        if(!setup_cache_for_test(&fid, &file_ptr, &cache_ptr, metadata_write_strategy) ) {
 
             nerrors++;
             fid = -1;
             cache_ptr = NULL;
-            if ( verbose ) {
-        HDfprintf(stdout, "%d:%s: setup_cache_for_test() failed.\n",
-                          world_mpi_rank, FUNC);
-            }
+            if(verbose)
+                HDfprintf(stdout, "%d:%s: setup_cache_for_test() failed.\n", world_mpi_rank, FUNC);
         }
 
-        if ( nerrors == 0 ) {
+        if(nerrors == 0) {
 
             config.version = H5AC__CURR_CACHE_CONFIG_VERSION;
 
-            if ( H5AC_get_cache_auto_resize_config(cache_ptr, &config)
-                 != SUCCEED ) {
-
-        nerrors++;
-            HDfprintf(stdout,
-                        "%d:%s: H5AC_get_cache_auto_resize_config() failed.\n",
-                        world_mpi_rank, FUNC);
-
-            } else {
-
+            if(H5AC_get_cache_auto_resize_config(cache_ptr, &config) != SUCCEED) {
+                nerrors++;
+                HDfprintf(stdout, "%d:%s: H5AC_get_cache_auto_resize_config() failed.\n", world_mpi_rank, FUNC);
+            }
+            else {
                 config.open_trace_file = TRUE;
-        strcpy(config.trace_file_name, "t_cache_trace.txt");
+                strcpy(config.trace_file_name, "t_cache_trace.txt");
 
-                if ( H5AC_set_cache_auto_resize_config(cache_ptr, &config)
-            != SUCCEED ) {
-
-            nerrors++;
-                HDfprintf(stdout,
-                         "%d:%s: H5AC_set_cache_auto_resize_config() failed.\n",
-                          world_mpi_rank, FUNC);
+                if(H5AC_set_cache_auto_resize_config(cache_ptr, &config) != SUCCEED) {
+                    nerrors++;
+                    HDfprintf(stdout, "%d:%s: H5AC_set_cache_auto_resize_config() failed.\n", world_mpi_rank, FUNC);
                 }
             }
-        }
+        } /* end if */
 
-    insert_entry(cache_ptr, file_ptr, 0, H5AC__NO_FLAGS_SET);
-    insert_entry(cache_ptr, file_ptr, 1, H5AC__NO_FLAGS_SET);
-    insert_entry(cache_ptr, file_ptr, 2, H5AC__NO_FLAGS_SET);
-    insert_entry(cache_ptr, file_ptr, 3, H5AC__NO_FLAGS_SET);
+        insert_entry(cache_ptr, file_ptr, 0, H5AC__NO_FLAGS_SET);
+        insert_entry(cache_ptr, file_ptr, 1, H5AC__NO_FLAGS_SET);
+        insert_entry(cache_ptr, file_ptr, 2, H5AC__NO_FLAGS_SET);
+        insert_entry(cache_ptr, file_ptr, 3, H5AC__NO_FLAGS_SET);
 
-    lock_entry(file_ptr, 0);
-    mark_entry_dirty(0);
-    unlock_entry(file_ptr, 0, H5AC__NO_FLAGS_SET);
+        lock_entry(file_ptr, 0);
+        mark_entry_dirty(0);
+        unlock_entry(file_ptr, 0, H5AC__NO_FLAGS_SET);
 
-    lock_entry(file_ptr, 1);
+        lock_entry(file_ptr, 1);
         pin_protected_entry(1, TRUE);
-    unlock_entry(file_ptr, 1, H5AC__NO_FLAGS_SET);
+        unlock_entry(file_ptr, 1, H5AC__NO_FLAGS_SET);
         unpin_entry(file_ptr, 1, TRUE, FALSE, FALSE);
 
         expunge_entry(file_ptr, 1);
 
-    lock_entry(file_ptr, 2);
+        lock_entry(file_ptr, 2);
         pin_protected_entry(2, TRUE);
-    unlock_entry(file_ptr, 2, H5AC__NO_FLAGS_SET);
-    mark_entry_dirty(2);
+        unlock_entry(file_ptr, 2, H5AC__NO_FLAGS_SET);
+        mark_entry_dirty(2);
         resize_entry(2, data[2].len / 2);
         resize_entry(2, data[2].len);
         unpin_entry(file_ptr, 2, TRUE, FALSE, FALSE);
 
-    move_entry(file_ptr, 0, 20);
-    move_entry(file_ptr, 0, 20);
+        move_entry(file_ptr, 0, 20);
+        move_entry(file_ptr, 0, 20);
 
-        if ( H5Fflush(fid, H5F_SCOPE_GLOBAL) < 0 ) {
+        if(H5Fflush(fid, H5F_SCOPE_GLOBAL) < 0) {
             nerrors++;
-            if ( verbose ) {
-            HDfprintf(stdout, "%d:%s: H5Fflush() failed.\n",
-                          world_mpi_rank, FUNC);
-            }
+            if(verbose)
+                HDfprintf(stdout, "%d:%s: H5Fflush() failed.\n", world_mpi_rank, FUNC);
         }
 
-        if ( nerrors == 0 ) {
-
+        if(nerrors == 0) {
             config.version = H5AC__CURR_CACHE_CONFIG_VERSION;
 
-            if ( H5AC_get_cache_auto_resize_config(cache_ptr, &config)
-                 != SUCCEED ) {
-
-        nerrors++;
-            HDfprintf(stdout,
-                        "%d:%s: H5AC_get_cache_auto_resize_config() failed.\n",
-                        world_mpi_rank, FUNC);
-
-            } else {
-
+            if(H5AC_get_cache_auto_resize_config(cache_ptr, &config) != SUCCEED) {
+                nerrors++;
+                HDfprintf(stdout, "%d:%s: H5AC_get_cache_auto_resize_config() failed.\n", world_mpi_rank, FUNC);
+            }
+            else {
                 config.open_trace_file = FALSE;
                 config.close_trace_file = TRUE;
-        config.trace_file_name[0] = '\0';
+                config.trace_file_name[0] = '\0';
 
-                if ( H5AC_set_cache_auto_resize_config(cache_ptr, &config)
-            != SUCCEED ) {
-
-            nerrors++;
-                HDfprintf(stdout,
-                        "%d:%s: H5AC_set_cache_auto_resize_config() failed.\n",
-                        world_mpi_rank, FUNC);
+                if(H5AC_set_cache_auto_resize_config(cache_ptr, &config) != SUCCEED) {
+                    nerrors++;
+                    HDfprintf(stdout, "%d:%s: H5AC_set_cache_auto_resize_config() failed.\n", world_mpi_rank, FUNC);
                 }
             }
-        }
-
-        if ( fid >= 0 ) {
+        } /* end if */
 
-            if ( ! take_down_cache(fid, cache_ptr) ) {
+        if(fid >= 0) {
+            if(!take_down_cache(fid, cache_ptr)) {
 
                 nerrors++;
-                if ( verbose ) {
-            HDfprintf(stdout, "%d:%s: take_down_cache() failed.\n",
-                              world_mpi_rank, FUNC);
-                }
+                if(verbose)
+                    HDfprintf(stdout, "%d:%s: take_down_cache() failed.\n", world_mpi_rank, FUNC);
             }
-        }
+        } /* end if */
 
         /* verify that all instance of datum are back where the started
          * and are clean.
          */
 
-        for ( i = 0; i < NUM_DATA_ENTRIES; i++ )
-        {
-            HDassert( data_index[i] == i );
-            HDassert( ! (data[i].dirty) );
+        for(i = 0; i < NUM_DATA_ENTRIES; i++) {
+            HDassert(data_index[i] == i);
+            HDassert(!(data[i].dirty));
         }
 
         /* compose the done message */
@@ -7091,117 +7048,121 @@ trace_file_check(int metadata_write_strategy)
         mssg.count     = 0; /* not used */
         mssg.magic     = MSSG_MAGIC;
 
-        if ( success ) {
-
+        if(success) {
             success = send_mssg(&mssg, FALSE);
 
-            if ( ! success ) {
-
+            if(!success) {
                 nerrors++;
-                if ( verbose ) {
-                    HDfprintf(stdout, "%d:%s: send_mssg() failed on done.\n",
-                              world_mpi_rank, FUNC);
-                }
+                if(verbose)
+                    HDfprintf(stdout, "%d:%s: send_mssg() failed on done.\n", world_mpi_rank, FUNC);
             }
-        }
+        } /* end if */
 
-        if ( nerrors == 0 ) {
+        if(nerrors == 0) {
+            HDsprintf(trace_file_name, "t_cache_trace.txt.%d", (int)file_mpi_rank);
 
-        sprintf(trace_file_name, "t_cache_trace.txt.%d",
-            (int)file_mpi_rank);
-
-        if ( (trace_file_ptr = HDfopen(trace_file_name, "r")) == NULL ) {
+            if((trace_file_ptr = HDfopen(trace_file_name, "r")) == NULL ) {
 
                 nerrors++;
-                if ( verbose ) {
-                    HDfprintf(stdout, "%d:%s: HDfopen failed.\n",
-                              world_mpi_rank, FUNC);
-                }
+                if(verbose)
+                    HDfprintf(stdout, "%d:%s: HDfopen failed.\n", world_mpi_rank, FUNC);
             }
-    }
-
-    i = 0;
-    while ( ( nerrors == 0 ) && ( ! done ) )
-    {
-        if ( (*expected_output)[i] == NULL ) {
-
-        expected_line_len = 0;
-
-        } else {
-
-        expected_line_len = HDstrlen((*expected_output)[i]);
-        }
+        } /* end if */
 
-        if ( HDfgets(buffer, 255, trace_file_ptr) != NULL ) {
 
-            actual_line_len = HDstrlen(buffer);
-
-        } else {
-
-            actual_line_len = 0;
-        }
+        i = 0;
+        while((nerrors == 0) && (!done)) {
+            /* Get lines of actual and expected data */
+            if((*expected_output)[i] == NULL)
+                expected_line_len = (size_t)0;
+            else
+                expected_line_len = HDstrlen((*expected_output)[i]);
+
+            if(HDfgets(buffer, 255, trace_file_ptr) != NULL)
+                actual_line_len = HDstrlen(buffer);
+            else
+                actual_line_len = (size_t)0;
+
+            /* Compare the lines */
+            /* Handle running out of data */
+            if((actual_line_len == 0) || (expected_line_len == 0)) {
+                if((actual_line_len == 0) && (expected_line_len == 0)) {
+                    /* Both ran out at the same time - we're done */
+                    done = TRUE;
+                }
+                else {
+                    /* One ran out before the other - BADNESS */
+                    nerrors++;
+                    if(verbose) {
+                        HDfprintf(stdout, "%d:%s: Unexpected data in trace file line %d.\n", world_mpi_rank, FUNC, i);
+                        if(expected_line_len == 0) {
+                            HDfprintf(stdout, "%d:%s: expected = \"%s\" %d\n", world_mpi_rank, FUNC, "<EMPTY>", expected_line_len);
+                            HDfprintf(stdout, "%d:%s: actual   = \"%s\" %d\n", world_mpi_rank, FUNC, buffer, actual_line_len);
+                        }
+                        if(actual_line_len == 0) {
+                            HDfprintf(stdout, "%d:%s: expected = \"%s\" %d\n", world_mpi_rank, FUNC, (*expected_output)[i], expected_line_len);
+                            HDfprintf(stdout, "%d:%s: actual   = \"%s\" %d\n", world_mpi_rank, FUNC, "<EMPTY>", actual_line_len);
+                        }
+                    }
+                    HDfprintf(stdout, "BADNESS BADNESS BADNESS\n");
+                }
+            }
+            /* We directly compare the header line (line 0) */
+            else if(0 == i) {
+                if((actual_line_len != expected_line_len) || (HDstrcmp(buffer, (*expected_output)[i]) != 0 )) {
 
-        if ( ( actual_line_len == 0 ) && ( expected_line_len == 0 ) ) {
+                    nerrors++;
+                    if(verbose) {
+                        HDfprintf(stdout, "%d:%s: Unexpected data in trace file line %d.\n", world_mpi_rank, FUNC, i);
+                        HDfprintf(stdout, "%d:%s: expected = \"%s\" %d\n", world_mpi_rank, FUNC, (*expected_output)[i], expected_line_len);
+                        HDfprintf(stdout, "%d:%s: actual   = \"%s\" %d\n", world_mpi_rank, FUNC, buffer, actual_line_len);
+                    }
+                }
+            }
+            /* All other lines we tokenize and just compare the function name. This
+             * keeps the test from being too fragile.
+             */
+            else {
+                char *tok = NULL;     /* token for actual line */
 
-            done = TRUE;
+                tok = HDstrtok(buffer, " ");
 
-        } else if ( ( actual_line_len != expected_line_len ) ||
-                ( HDstrcmp(buffer, (*expected_output)[i]) != 0 ) ) {
+                if(HDstrcmp(tok, (*expected_output)[i]) != 0 ) {
 
-            nerrors++;
-                if ( verbose ) {
-                    HDfprintf(stdout,
-                "%d:%s: Unexpected data in trace file line %d.\n",
-                              world_mpi_rank, FUNC, i);
-            HDfprintf(stdout, "%d:%s: expected = \"%s\" %d\n",
-                world_mpi_rank, FUNC, (*expected_output)[i],
-                expected_line_len);
-            HDfprintf(stdout, "%d:%s: actual   = \"%s\" %d\n",
-                world_mpi_rank, FUNC, buffer,
-                actual_line_len);
+                    nerrors++;
+                    if(verbose) {
+                        HDfprintf(stdout, "%d:%s: Unexpected data in trace file line %d.\n", world_mpi_rank, FUNC, i);
+                        HDfprintf(stdout, "%d:%s: expected = \"%s\"\n", world_mpi_rank, FUNC, (*expected_output)[i]);
+                        HDfprintf(stdout, "%d:%s: actual   = \"%s\"\n", world_mpi_rank, FUNC, tok);
+                    }
                 }
-        } else {
-            i++;
-        }
-    }
+            } /* end else */
 
-    if ( trace_file_ptr != NULL ) {
+            i++;
+        } /* end while */
 
-        HDfclose(trace_file_ptr);
-        trace_file_ptr = NULL;
-#if 1
-        HDremove(trace_file_name);
-#endif
+        /* Clean up the trace file */
+        if(trace_file_ptr != NULL) {
+            HDfclose(trace_file_ptr);
+            trace_file_ptr = NULL;
+            HDremove(trace_file_name);
         }
-    }
+    } /* end giant else that runs clients */
 
     max_nerrors = get_max_nerrors();
 
-    if ( world_mpi_rank == 0 ) {
-
-    if ( max_nerrors == 0 ) {
-
-        PASSED();
-
-        } else {
+    if(world_mpi_rank == 0) {
 
+        if(max_nerrors == 0) {
+            PASSED();
+        }
+        else {
             failures++;
             H5_FAILED();
         }
     }
 
-    success = ( ( success ) && ( max_nerrors == 0 ) );
-
-#else /* H5_METADATA_TRACE_FILE */
-
-    if ( world_mpi_rank == 0 ) {
-
-        SKIPPED();
-
-        HDfprintf(stdout, " trace file support disabled.\n");
-    }
-
-#endif /* H5_METADATA_TRACE_FILE */
+    success = ((success) && (max_nerrors == 0));
 
     return(success);
 
diff --git a/testpar/testpflush.sh.in b/testpar/testpflush.sh.in
new file mode 100644
index 0000000..02f0e26
--- /dev/null
+++ b/testpar/testpflush.sh.in
@@ -0,0 +1,64 @@
+#! /bin/sh
+#
+# Copyright by The HDF Group.
+# Copyright by the Board of Trustees of the University of Illinois.
+# All rights reserved.
+#
+# This file is part of HDF5.  The full HDF5 copyright notice, including
+# terms governing use, modification, and redistribution, is contained in
+# the COPYING file, which can be found at the root of the source code
+# distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.
+# If you do not have access to either file, you may request a copy from
+# help@hdfgroup.org.
+#
+#
+# Test script for the parallel flush test
+#
+# The parallel flush test uses two programs to test flush operations
+# in parallel HDF5. The first program purposely exits without calling
+# MPI_Finalize(), which is an error under the MPI standard and mpiexec
+# in some implementations will return an error code even though all
+# processes exit successfully. This script lets us swallow the error
+# from the first program.
+#
+# True errors in the first program will be detected as errors in the
+# second program, so watch out for that.
+#
+# Programmer:   Dana Robinson
+#               Fall 2018
+
+# The build (current) directory might be different than the source directory.
+if test -z "$srcdir"; then
+   srcdir=.
+fi
+
+# Turn the $$ we use to avoid Autotools munging into $
+#
+# Allowing $$ to substitute in both the RUNPARALLEL string and the
+# regexp is intentional. There doesn't seem to be a way around
+# this using quote shenanigans. The downside is that there is a remote
+# chance that the shell's pid will match a number in the RUNPARALLEL
+# variable, but that seems less likely to cause problems than expecting
+# library builders to specify two almost identical versions of the
+# RUNPARALLEL command, one for use in scripts and one via Makefiles.
+RUNPARALLELSCRIPT=`echo "@RUNPARALLEL@" | sed "s/$$/\$/g"`
+
+# ==========================================
+# Run the first parallel flush test program
+# (note that we ignore any errors here)
+# ==========================================
+echo "*** NOTE ***********************************************************"
+echo "You may see complaints from mpiexec et al. that not all processes"
+echo "called MPI_Finalize(). This is an intended characteristic of the"
+echo "test and should not be considered an  error."
+echo "********************************************************************"
+eval ${RUNPARALLELSCRIPT} ./t_pflush1
+
+
+# ===========================================
+# Run the second parallel flush test program
+# The return code of this call is the return
+# code of the script.
+# ===========================================
+eval ${RUNPARALLELSCRIPT} ./t_pflush2
+
diff --git a/tools/test/h5jam/tellub.c b/tools/test/h5jam/tellub.c
index aa779b3..559c677 100644
--- a/tools/test/h5jam/tellub.c
+++ b/tools/test/h5jam/tellub.c
@@ -53,7 +53,7 @@ usage (const char *prog)
 /*-------------------------------------------------------------------------
  * Function:    parse_command_line
  *
- * Purpose:     Parse the command line for the h5dumper.
+ * Purpose:     Parse the command line.
  *
  * Return:      Success:    void
  *              Failure:    Exits program with EXIT_FAILURE value.
@@ -89,7 +89,7 @@ parse_command_line (int argc, const char *argv[])
 /*-------------------------------------------------------------------------
  * Function:    main
  *
- * Purpose:     HDF5 user block unjammer
+ * Purpose:     HDF5 user block tell size
  *
  * Return:      EXIT_SUCCESS/EXIT_FAILURE
  *-------------------------------------------------------------------------
diff --git a/tools/test/h5repack/CMakeTests.cmake b/tools/test/h5repack/CMakeTests.cmake
index ad468f0..c2a2be7 100644
--- a/tools/test/h5repack/CMakeTests.cmake
+++ b/tools/test/h5repack/CMakeTests.cmake
@@ -16,39 +16,6 @@
 ##############################################################################
 ##############################################################################
 
-  if (HDF5_TEST_VFD)
-    set (VFD_LIST
-        sec2
-        stdio
-        core
-        split
-        multi
-        family
-    )
-
-    if (DIRECT_VFD)
-      set (VFD_LIST ${VFD_LIST} direct)
-    endif ()
-
-    macro (ADD_VFD_TEST vfdname resultcode)
-      add_test (
-        NAME H5REPACK-VFD-${vfdname}-h5repacktest
-        COMMAND "${CMAKE_COMMAND}"
-            -D "TEST_PROGRAM=$<TARGET_FILE:h5repacktest>"
-            -D "TEST_ARGS:STRING="
-            -D "TEST_VFD:STRING=${vfdname}"
-            -D "TEST_EXPECT=${resultcode}"
-            -D "TEST_OUTPUT=h5repacktest"
-            -D "TEST_FOLDER=${PROJECT_BINARY_DIR}"
-            -P "${HDF_RESOURCES_DIR}/vfdTest.cmake"
-      )
-      if (NOT "${last_test}" STREQUAL "")
-        set_tests_properties (H5REPACK-VFD-${vfdname}-h5repacktest PROPERTIES DEPENDS ${last_test})
-      endif ()
-      set (last_test "H5REPACK-VFD-${vfdname}-h5repacktest")
-    endmacro ()
-  endif ()
-
   # --------------------------------------------------------------------
   # Copy all the HDF5 files from the source directory into the test directory
   # --------------------------------------------------------------------
@@ -1459,9 +1426,12 @@ if (BUILD_SHARED_LIBS)
   ADD_H5_UD_TEST (plugin_zero 0 h5repack_layout.h5 -v -f UD=250,0,0)
 endif ()
 
-  if (HDF5_TEST_VFD)
-    # Run test with different Virtual File Driver
-    foreach (vfd ${VFD_LIST})
-      ADD_VFD_TEST (${vfd} 0)
-    endforeach ()
-  endif ()
+##############################################################################
+##############################################################################
+###                         V F D   T E S T S                              ###
+##############################################################################
+##############################################################################
+
+if (HDF5_TEST_VFD)
+  include (CMakeVFDTests.cmake)
+endif ()
diff --git a/tools/test/h5repack/CMakeVFDTests.cmake b/tools/test/h5repack/CMakeVFDTests.cmake
new file mode 100644
index 0000000..2042f31
--- /dev/null
+++ b/tools/test/h5repack/CMakeVFDTests.cmake
@@ -0,0 +1,65 @@
+#
+# Copyright by The HDF Group.
+# All rights reserved.
+#
+# This file is part of HDF5.  The full HDF5 copyright notice, including
+# terms governing use, modification, and redistribution, is contained in
+# the COPYING file, which can be found at the root of the source code
+# distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.
+# If you do not have access to either file, you may request a copy from
+# help@hdfgroup.org.
+#
+
+##############################################################################
+##############################################################################
+###           T E S T I N G                                                ###
+##############################################################################
+##############################################################################
+
+    set (VFD_LIST
+        sec2
+        stdio
+        core
+        split
+        multi
+        family
+    )
+
+    if (DIRECT_VFD)
+      set (VFD_LIST ${VFD_LIST} direct)
+    endif ()
+
+##############################################################################
+##############################################################################
+###           T H E   T E S T S  M A C R O S                               ###
+##############################################################################
+##############################################################################
+
+  macro (ADD_VFD_TEST vfdname resultcode)
+    add_test (
+      NAME H5REPACK-VFD-${vfdname}-h5repacktest
+      COMMAND "${CMAKE_COMMAND}"
+          -D "TEST_PROGRAM=$<TARGET_FILE:h5repacktest>"
+          -D "TEST_ARGS:STRING="
+          -D "TEST_VFD:STRING=${vfdname}"
+          -D "TEST_EXPECT=${resultcode}"
+          -D "TEST_OUTPUT=h5repacktest"
+          -D "TEST_FOLDER=${PROJECT_BINARY_DIR}"
+          -P "${HDF_RESOURCES_DIR}/vfdTest.cmake"
+    )
+    if (NOT "${last_test}" STREQUAL "")
+      set_tests_properties (H5REPACK-VFD-${vfdname}-h5repacktest PROPERTIES DEPENDS ${last_test})
+    endif ()
+    set (last_test "H5REPACK-VFD-${vfdname}-h5repacktest")
+  endmacro ()
+
+##############################################################################
+##############################################################################
+###           T H E   T E S T S                                            ###
+##############################################################################
+##############################################################################
+
+  # Run test with different Virtual File Driver
+  foreach (vfd ${VFD_LIST})
+    ADD_VFD_TEST (${vfd} 0)
+  endforeach ()