[svn-r29224] Brought alpha2 branch in sync with revise_chunks (up to r29219)

Note: generated autotools files are from a VM and not THG
      machines. These will be updated immediately after
      check-in.

Tested on: 64-bit Ubuntu 15.10 w/ gcc 5.2.1
           autotools serial w/ Fortran & C++
           autotools parallel (MPICH 3.1.4) w/ Fortran
           CMake serial (cmakehdf5 w/ CMake 3.3.2)

46 files changed, 1491 insertions, 493 deletions

diff --git a/tools/h5format_convert/Makefile.in b/tools/h5format_convert/Makefile.in
index 79bc42f..fd31dce 100644
--- a/tools/h5format_convert/Makefile.in
+++ b/tools/h5format_convert/Makefile.in
@@ -432,16 +432,17 @@ AM_DEFAULT_VERBOSITY = @AM_DEFAULT_VERBOSITY@
 AM_FCFLAGS = @AM_FCFLAGS@ @H5_FCFLAGS@
 AM_LDFLAGS = @AM_LDFLAGS@ @H5_LDFLAGS@
 AR = @AR@
+ASSERTS = @ASSERTS@
 AUTOCONF = @AUTOCONF@
 AUTOHEADER = @AUTOHEADER@
 AUTOMAKE = @AUTOMAKE@
 AWK = @AWK@
+BUILD_MODE = @BUILD_MODE@
 BYTESEX = @BYTESEX@
 CC = @CC@
 CCDEPMODE = @CCDEPMODE@
 CC_VERSION = @CC_VERSION@
 CFLAGS = @CFLAGS@
-CLEARFILEBUF = @CLEARFILEBUF@
 CODESTACK = @CODESTACK@
 CONFIG_DATE = @CONFIG_DATE@
 CONFIG_MODE = @CONFIG_MODE@
@@ -454,7 +455,6 @@ CXXDEPMODE = @CXXDEPMODE@
 CXXFLAGS = @CXXFLAGS@
 CXX_VERSION = @CXX_VERSION@
 CYGPATH_W = @CYGPATH_W@
-DEBUG_PKG = @DEBUG_PKG@
 DEFAULT_API_VERSION = @DEFAULT_API_VERSION@
 DEFS = @DEFS@
 DEPDIR = @DEPDIR@
@@ -516,8 +516,8 @@ INSTALL_DATA = @INSTALL_DATA@
 INSTALL_PROGRAM = @INSTALL_PROGRAM@
 INSTALL_SCRIPT = @INSTALL_SCRIPT@
 INSTALL_STRIP_PROGRAM = @INSTALL_STRIP_PROGRAM@
-INSTRUMENT = @INSTRUMENT@
 INSTRUMENT_LIBRARY = @INSTRUMENT_LIBRARY@
+INTERNAL_DEBUG_OUTPUT = @INTERNAL_DEBUG_OUTPUT@
 LD = @LD@
 LDFLAGS = @LDFLAGS@
 LIBOBJS = @LIBOBJS@
@@ -528,11 +528,11 @@ LL_PATH = @LL_PATH@
 LN_S = @LN_S@
 LTLIBOBJS = @LTLIBOBJS@
 LT_STATIC_EXEC = @LT_STATIC_EXEC@
-LT_SYS_LIBRARY_PATH = @LT_SYS_LIBRARY_PATH@
 MAINT = @MAINT@
 MAKEINFO = @MAKEINFO@
 MANIFEST_TOOL = @MANIFEST_TOOL@
 MEMORYALLOCSANITYCHECK = @MEMORYALLOCSANITYCHECK@
+METADATATRACEFILE = @METADATATRACEFILE@
 MKDIR_P = @MKDIR_P@
 MPE = @MPE@
 NM = @NM@
@@ -540,6 +540,7 @@ NMEDIT = @NMEDIT@
 OBJDUMP = @OBJDUMP@
 OBJECT_NAMELEN_DEFAULT_F = @OBJECT_NAMELEN_DEFAULT_F@
 OBJEXT = @OBJEXT@
+OPTIMIZATION = @OPTIMIZATION@
 OTOOL = @OTOOL@
 OTOOL64 = @OTOOL64@
 PACKAGE = @PACKAGE@
@@ -563,6 +564,7 @@ PAC_FORTRAN_NATIVE_REAL_KIND = @PAC_FORTRAN_NATIVE_REAL_KIND@
 PAC_FORTRAN_NATIVE_REAL_SIZEOF = @PAC_FORTRAN_NATIVE_REAL_SIZEOF@
 PARALLEL = @PARALLEL@
 PATH_SEPARATOR = @PATH_SEPARATOR@
+PROFILING = @PROFILING@
 RANLIB = @RANLIB@
 ROOT = @ROOT@
 RUNPARALLEL = @RUNPARALLEL@
@@ -578,6 +580,7 @@ STATIC_EXEC = @STATIC_EXEC@
 STATIC_SHARED = @STATIC_SHARED@
 STRICT_FORMAT_CHECKS = @STRICT_FORMAT_CHECKS@
 STRIP = @STRIP@
+SYMBOLS = @SYMBOLS@
 TESTPARALLEL = @TESTPARALLEL@
 THREADSAFE = @THREADSAFE@
 TIME = @TIME@
diff --git a/tools/h5format_convert/h5fc_gentest.c b/tools/h5format_convert/h5fc_gentest.c
index 888aa27..54ef3df 100644
--- a/tools/h5format_convert/h5fc_gentest.c
+++ b/tools/h5format_convert/h5fc_gentest.c
@@ -23,15 +23,30 @@
  * of the expected output and update the corresponding *.ddl files.
  */
 #include "hdf5.h"
+#include "H5private.h"
+
+#define NON_V3_FILE		"h5fc_non_v3.h5"
+#define EDGE_V3_FILE		"h5fc_edge_v3.h5"
+
+const char *FILENAME[] = {
+    "h5fc_ext1_i.h5",	/* 0 */
+    "h5fc_ext1_s.h5",	/* 1 */
+    "h5fc_ext1_f.h5",	/* 2 */
+    "h5fc_ext2_is.h5", 	/* 3 */
+    "h5fc_ext2_if.h5",	/* 4 */
+    "h5fc_ext2_sf.h5", 	/* 5 */
+    "h5fc_ext3_isf.h5",	/* 6 */ 
+    "h5fc_ext_none.h5",	/* 7 */ 
+    NULL
+};
 
 #define GROUP			"GROUP"
 
-#define OLD_V1_FILE		"h5fc_v1.h5"
-#define DSET_NON_CHUNKED	"DSET_NON_CHUNKED"
 #define DSET_BT1		"DSET_BT1"
 #define DSET_NDATA_BT1		"DSET_NDATA_BT1"
+#define DSET_COMPACT		"DSET_COMPACT"
+#define DSET_CONTIGUOUS		"DSET_CONTIGUOUS"
 
-#define LATEST_V3_FILE		"h5fc_latest_v3.h5"
 #define DSET_EA			"DSET_EA"
 #define DSET_NDATA_EA		"DSET_NDATA_EA"
 #define DSET_BT2		"DSET_BT2"
@@ -41,58 +56,84 @@
 #define DSET_NONE		"DSET_NONE"
 #define DSET_NDATA_NONE		"DSET_NDATA_NONE"
 
-#define NON_V3_FILE		"h5fc_non_v3.h5"
-
-#define EDGE_V3_FILE		"h5fc_edge_v3.h5"
 #define DSET_EDGE		"DSET_EDGE"
 
+#define ISTORE_IK  64
+
 /*
- * Function: gen_old() 
+ * Function: gen_latest() 
  *
- * Create an old format file with:
- *	1) 1 non-chunked dataset
- *	2) 2 chunked datasets with version 1 B-tree chunk indexing type: with/without data
+ * Create a file with write+latest-format--this will result in v3 superblock+latest version support:
+ *	1) 2 chunked datasets with extensible array chunk indexing type (with/without data)
+ *	2) 2 chunked datasets with version 2 B-tree chunk indexing type (with/without data)
+ *	3) 2 chunked datasets with fixed array chunk indexing type (with/without data)
+ *	4) 2 chunked datasets with implicit array chunk indexing type (with/without data)
+ */
+
+/*
+ * Function: gen_non() 
+ *
+ * Create a file with SWMR write+non-latest-format--this will result in v3 superbock+latest version support:
+ *	1) 1 chunked dataset with extensible array chunk indexing type (without data)
+ *	2) 1 chunked dataset with version 2 B-tree chunk indexing type (with data)
+ * Re-open the file with write+non-latest-format and create:
+ *	3) 1 chunked dataset with version 2 B-tree chunk indexing type (without data)
+ * 	4) 1 chunked dataset with extensible array indexing type (with data)
+ *	5) 1 compact and 1 contiguous datasets
  */
 static void
-gen_old(const char *fname)
+gen_non(const char *fname)
 {
-    hid_t	fid = -1;	 	/* file id */
-    hid_t	fcpl = -1;	 	
-    hid_t	gid = -1;	 	/* group id */
-    hid_t   	sid = -1;	 	/* space id */
-    hid_t	dcpl = -1;	 	/* dataset creation property id */
+    hid_t	fid = -1;		/* file id */
+    hid_t	fcpl = -1;		/* file creation property list */
+    hid_t	gid = -1;		/* group id */
+    hid_t   	sid = -1;       	/* space id */
+    hid_t	dcpl = -1;		/* dataset creation property id */
     hid_t	did1 = -1, did2 = -1;	/* dataset id */
     hsize_t 	dims1[1] = {10};     	/* dataset dimension */
     hsize_t 	dims2[2] = {4, 6};     	/* dataset dimension */
+    hsize_t	max_dims[2];		/* maximum dataset dimension */
     hsize_t 	c_dims[2] = {2, 3};    	/* chunk dimension */
     int		i;		    	/* local index variable */
     int     	buf[24];            	/* data buffer */
 
     if((fcpl = H5Pcreate(H5P_FILE_CREATE)) < 0)
         goto error;
-
+    if(H5Pset_shared_mesg_nindexes(fcpl, 4) < 0)
+        goto error;
     if(H5Pset_istore_k(fcpl, 64) < 0)
         goto error;
 
-    /* Create file */
-    if((fid = H5Fcreate(fname, H5F_ACC_TRUNC, fcpl, H5P_DEFAULT)) < 0)
+    /* Create a new file with SWMR_WRITE + non-latest-format */
+    if((fid = H5Fcreate(fname, H5F_ACC_TRUNC|H5F_ACC_SWMR_WRITE, fcpl, H5P_DEFAULT)) < 0)
 	goto error;
 
     /* Create a group */
     if((gid = H5Gcreate2(fid, GROUP, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
 	goto error;
 
+    /* Create data */
+    for(i = 0; i < 24; i++)
+	buf[i] = i;
+
+    /* Set chunk */
+    if((dcpl = H5Pcreate(H5P_DATASET_CREATE)) < 0)
+	goto error;
+    if(H5Pset_chunk(dcpl, 2, c_dims) < 0)
+	goto error;
 
     /* 
-     * Create a non-chunked dataset 
+     * Create a chunked dataset with extensible array chunk indexing type (without data)
      */
 
     /* Create dataspace */
-    if((sid = H5Screate_simple(1, dims1, NULL)) < 0)
+    max_dims[0] = 10;
+    max_dims[1] = H5S_UNLIMITED;
+    if((sid = H5Screate_simple(2, dims2, max_dims)) < 0)
 	goto error;
 
     /* Create the dataset */
-    if((did1  = H5Dcreate2(fid, DSET_NON_CHUNKED, H5T_NATIVE_INT, sid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+    if((did1  = H5Dcreate2(fid, DSET_NDATA_EA, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
 	goto error;
 
     /* Closing */
@@ -102,114 +143,70 @@ gen_old(const char *fname)
 	goto error;
 
     /* 
-     * Create two chunked datasets with version 1 B-tree chunk indexing type
-     * (one with data, one without data)
+     * Create a chunked dataset with version 2 B-tree chunk indexing type (with data)
      */
 
-    /* Create data */
-    for(i = 0; i < 24; i++)
-	buf[i] = i;
-
-    /* Set chunk */
-    if((dcpl = H5Pcreate(H5P_DATASET_CREATE)) < 0)
-	goto error;
-    if(H5Pset_chunk(dcpl, 2, c_dims) < 0)
-	goto error;
-
     /* Create dataspace */
-    if((sid = H5Screate_simple(2, dims2, NULL)) < 0)
+    max_dims[0] = 10;
+    max_dims[0] = H5S_UNLIMITED;
+    max_dims[1] = H5S_UNLIMITED;
+    if((sid = H5Screate_simple(2, dims2, max_dims)) < 0)
 	goto error;
 
-    /* Create the 2 datasets */
-    if((did1 = H5Dcreate2(fid, DSET_NDATA_BT1, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+    /* Create the dataset */
+    if((did1  = H5Dcreate2(gid, DSET_BT2, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
 	goto error;
 
-    if((did2 = H5Dcreate2(gid, DSET_BT1, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
-	goto error;
-    
-    /* Write to one dataset */
-    if(H5Dwrite(did2, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf) < 0)
+    /* Write to the dataset */
+    if(H5Dwrite(did1, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf) < 0)
 	goto error;
 
     /* Closing */
-    if(H5Pclose(dcpl) < 0)
-	goto error;
     if(H5Sclose(sid) < 0)
 	goto error;
     if(H5Dclose(did1) < 0)
 	goto error;
-    if(H5Dclose(did2) < 0)
+    if(H5Pclose(dcpl) < 0)
 	goto error;
-
     if(H5Gclose(gid) < 0)
 	goto error;
     if(H5Fclose(fid) < 0)
 	goto error;
 
-error:
-    H5E_BEGIN_TRY {
-        H5Pclose(dcpl);
-        H5Sclose(sid);
-        H5Dclose(did1);
-        H5Dclose(did2);
-        H5Gclose(gid);
-        H5Fclose(fid);
-    } H5E_END_TRY;
+    /* Re-open the file with old format */
+    if((fid = H5Fopen(fname, H5F_ACC_RDWR, H5P_DEFAULT)) < 0)
+	goto error;
 
-} /* gen_old() */
+    /* Open the group */
+    if((gid = H5Gopen2(fid, GROUP, H5P_DEFAULT)) < 0)
+	goto error;
 
-/*
- * Function: gen_latest() 
- *
- * Create a file with write+latest-format--this will result in v3 superblock+latest version support:
- *	1) 2 chunked datasets with extensible array chunk indexing type (with/without data)
- *	2) 2 chunked datasets with version 2 B-tree chunk indexing type (with/without data)
- *	3) 2 chunked datasets with fixed array chunk indexing type (with/without data)
- *	4) 2 chunked datasets with implicit array chunk indexing type (with/without data)
- */
-static void
-gen_latest(const char *fname)
-{
-    hid_t	fid = -1;	 	/* file id */
-    hid_t	fapl = -1;	       	/* file access property list */
-    hid_t	fcpl = -1;	       	/* file creation property list */
-    hid_t	gid = -1;	       	/* group id */
-    hid_t   	sid = -1;       	/* space id */
-    hid_t	dcpl = -1;	    	/* dataset creation property id */
-    hid_t	did1 = -1, did2 = -1;	/* dataset id */
-    hsize_t 	dims2[2] = {4, 6};     	/* dataset dimension */
-    hsize_t	max_dims[2];		/* maximum dataset dimension */
-    hsize_t 	c_dims[2] = {2, 3};    	/* chunk dimension */
-    int		i;		    	/* local index variable */
-    int     	buf[24];            	/* data buffer */
+    /*
+     * Create a dataset with version 2 B-btree chunk indexing type (without data)
+     */
 
-    /* Create a new format file */
-    if((fapl = H5Pcreate(H5P_FILE_ACCESS)) < 0)
+    /* Set chunk */
+    if((dcpl = H5Pcreate(H5P_DATASET_CREATE)) < 0)
 	goto error;
-    if(H5Pset_libver_bounds(fapl, H5F_LIBVER_LATEST, H5F_LIBVER_LATEST) < 0)
+    if(H5Pset_chunk(dcpl, 2, c_dims) < 0)
 	goto error;
 
-    if((fcpl = H5Pcreate(H5P_FILE_CREATE)) < 0)
-        goto error;
-    if(H5Pset_shared_mesg_nindexes(fcpl, 4) < 0)
-        goto error;
-
-    if((fid = H5Fcreate(fname, H5F_ACC_TRUNC, fcpl, fapl)) < 0)
+    /* Create dataspace */
+    max_dims[0] = H5S_UNLIMITED;
+    max_dims[1] = H5S_UNLIMITED;
+    if((sid = H5Screate_simple(2, dims2, max_dims)) < 0)
 	goto error;
 
-    /* Create a group */
-    if((gid = H5Gcreate2(fid, GROUP, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+    /* Create the dataset */
+    if((did1 = H5Dcreate2(fid, DSET_NDATA_BT2, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
 	goto error;
 
-    /* Set chunk */
-    if((dcpl = H5Pcreate(H5P_DATASET_CREATE)) < 0)
-	goto error;
-    if(H5Pset_chunk(dcpl, 2, c_dims) < 0)
+    /* Close the dataspace */
+    if(H5Sclose(sid) < 0)
 	goto error;
 
-    /* 
-     * Create 2 chunked datasets with extensible array chunk indexing type 
-     * (one with data; one without data)
+    /*
+     * Create a dataset with extensible array chunk indexing type (with data) in the group
      */
 
     /* Create dataspace */
@@ -218,127 +215,155 @@ gen_latest(const char *fname)
     if((sid = H5Screate_simple(2, dims2, max_dims)) < 0)
 	goto error;
 
-    /* Create the 2 datasets */
-    if((did1  = H5Dcreate2(gid, DSET_NDATA_EA, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
-	goto error;
-
-    if((did2  = H5Dcreate2(fid, DSET_EA, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+    /* Create the dataset */
+    if((did2 = H5Dcreate2(gid, DSET_EA, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
 	goto error;
 
-    /* Create data */
-    for(i = 0; i < 24; i++)
-	buf[i] = i;
-
-    /* Write to one dataset */
+    /* Write to the dataset */
     if(H5Dwrite(did2, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf) < 0)
 	goto error;
 
     /* Closing */
     if(H5Sclose(sid) < 0)
 	goto error;
+    if(H5Pclose(dcpl) < 0)
+	goto error;
     if(H5Dclose(did1) < 0)
 	goto error;
     if(H5Dclose(did2) < 0)
 	goto error;
 
-
     /* 
-     * Create 2 chunked datasets with version 2 B-tree chunk indexing type 
-     * (one with data; one without data)
+     * Create a compact dataset in the group
      */
 
     /* Create dataspace */
-    max_dims[0] = 10;
-    max_dims[0] = H5S_UNLIMITED;
-    max_dims[1] = H5S_UNLIMITED;
-    if((sid = H5Screate_simple(2, dims2, max_dims)) < 0)
+    if((sid = H5Screate_simple(1, dims1, NULL)) < 0)
 	goto error;
 
-    /* Create the 2 datasets */
-    if((did1  = H5Dcreate2(fid, DSET_NDATA_BT2, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+    if((dcpl = H5Pcreate(H5P_DATASET_CREATE)) < 0)
 	goto error;
-
-    if((did2  = H5Dcreate2(gid, DSET_BT2, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+    if(H5Pset_layout(dcpl, H5D_COMPACT) < 0)
 	goto error;
 
-    /* Write to one dataset */
-    if(H5Dwrite(did2, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf) < 0)
+    /* Create the dataset */
+    if((did1  = H5Dcreate2(gid, DSET_COMPACT, H5T_NATIVE_INT, sid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
 	goto error;
 
     /* Closing */
-    if(H5Sclose(sid) < 0)
-	goto error;
     if(H5Dclose(did1) < 0)
 	goto error;
-    if(H5Dclose(did2) < 0)
+    if(H5Pclose(dcpl) < 0)
+	goto error;
+    if(H5Sclose(sid) < 0)
 	goto error;
 
-    /*
-     * Create 2 chunked datasets with fixed array chunk indexing type 
-     * (one with data; one without data)
+    /* 
+     * Create a contiguous dataset with (2d with data) in the file
      */
-
-    /* Create dataspace */
-    max_dims[0] = 20;
-    max_dims[1] = 10;
-    if((sid = H5Screate_simple(2, dims2, max_dims)) < 0)
+    if((dcpl = H5Pcreate(H5P_DATASET_CREATE)) < 0)
 	goto error;
-
-    /* Create the datasets */
-    if((did1  = H5Dcreate2(fid, DSET_FA, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+    if(H5Pset_layout(dcpl, H5D_CONTIGUOUS) < 0)
 	goto error;
 
-    if((did2  = H5Dcreate2(gid, DSET_NDATA_FA, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+    if((sid = H5Screate_simple(2, dims2, NULL)) < 0)
 	goto error;
 
+    /* Create the dataset */
+    if((did2  = H5Dcreate2(fid, DSET_CONTIGUOUS, H5T_NATIVE_INT, sid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+	goto error;
     /* Write to the dataset */
-    if(H5Dwrite(did1, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf) < 0)
+    if(H5Dwrite(did2, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf) < 0)
 	goto error;
 
     /* Closing */
+    if(H5Dclose(did2) < 0)
+	goto error;
+    if(H5Pclose(dcpl) < 0)
+	goto error;
     if(H5Sclose(sid) < 0)
 	goto error;
-    if(H5Dclose(did1) < 0)
+
+    if(H5Gclose(gid) < 0)
 	goto error;
-    if(H5Dclose(did2) < 0)
+    if(H5Fclose(fid) < 0)
 	goto error;
 
+error:
+    H5E_BEGIN_TRY {
+        H5Pclose(dcpl);
+        H5Sclose(sid);
+        H5Dclose(did1);
+        H5Dclose(did2);
+        H5Gclose(gid);
+        H5Fclose(fid);
+    } H5E_END_TRY;
 
-    /* 
-     * Create 2 chunked datasets with implicit chunk indexing type 
-     * (one with data; one without data)
-     */
+} /* gen_non() */
 
-    /* Create dataspace */
-    if((sid = H5Screate_simple(2, dims2, NULL)) < 0)
-	goto error;
+/*
+ * Function: gen_edge() 
+ *
+ * Create a file with write+latest-format--this will result in v3 superblock+latest version support:
+ *	A dataset: chunked, filtered, H5D_CHUNK_DONT_FILTER_PARTIAL_CHUNKS enabled
+ *	(i.e. the dataset does not filter partial edge chunks)
+ */
+static void
+gen_edge(const char *fname)
+{
+    hid_t	fid = -1;	    	/* file id */
+    hid_t	fapl = -1;	       	/* file access property list */
+    hid_t   	sid = -1;       	/* dataspace id */
+    hid_t	dcpl = -1;	    	/* dataset creation property id */
+    hid_t	did = -1;		/* dataset id */
+    hsize_t 	dims2[2] = {12, 6};	/* Dataset dimensions */
+    hsize_t 	c_dims[2] = {5, 5};	/* Chunk dimensions */
+    float 	buf[12][6];            	/* Buffer for writing data */
+    int		i, j;		    	/* local index variable */
 
-    /* Set early allocation */
-    if(H5Pset_alloc_time(dcpl, H5D_ALLOC_TIME_EARLY) < 0)
+    /* Create a new format file */
+    if((fapl = H5Pcreate(H5P_FILE_ACCESS)) < 0)
 	goto error;
-
-    /* Create the 2 datasets */
-    if((did1  = H5Dcreate2(fid, DSET_NONE, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+    if(H5Pset_libver_bounds(fapl, H5F_LIBVER_LATEST, H5F_LIBVER_LATEST) < 0)
+	goto error;
+    if((fid = H5Fcreate(fname, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0)
 	goto error;
 
-    if((did2  = H5Dcreate2(gid, DSET_NDATA_NONE, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+    /* Set chunk, filter, no-filter-edge-chunk */
+    if((dcpl = H5Pcreate(H5P_DATASET_CREATE)) < 0)
 	goto error;
+    if(H5Pset_chunk(dcpl, 2, c_dims) < 0)
+	goto error;
+    if(H5Pset_deflate(dcpl, 9) < 0)
+        goto error;
+    if(H5Pset_chunk_opts(dcpl, H5D_CHUNK_DONT_FILTER_PARTIAL_CHUNKS) < 0)
+        goto error;
 
-    /* Write to one dataset */
-    if(H5Dwrite(did1, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf) < 0)
+    /* Create dataspace */
+    if((sid = H5Screate_simple(2, dims2, NULL)) < 0)
+        goto error;
+
+    /* Create the dataset */
+    if((did = H5Dcreate2(fid, DSET_EDGE, H5T_NATIVE_FLOAT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+        goto error;
+
+    /* Create data */
+    for (i = 0; i< 12; i++)
+        for (j = 0; j< 6; j++)
+            buf[i][j] = 100.0F;
+
+    /* Write to the dataset */
+    if(H5Dwrite(did, H5T_NATIVE_FLOAT, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf) < 0)
 	goto error;
 
     /* Closing */
-    if(H5Dclose(did1) < 0)
-	goto error;
-    if(H5Dclose(did2) < 0)
+    if(H5Pclose(dcpl) < 0)
 	goto error;
     if(H5Sclose(sid) < 0)
 	goto error;
-
-    if(H5Pclose(dcpl) < 0)
+    if(H5Dclose(did) < 0)
 	goto error;
-    if(H5Gclose(gid) < 0)
+    if(H5Pclose(fapl) < 0)
 	goto error;
     if(H5Fclose(fid) < 0)
 	goto error;
@@ -347,34 +372,35 @@ error:
     H5E_BEGIN_TRY {
         H5Pclose(dcpl);
         H5Sclose(sid);
-        H5Dclose(did1);
-        H5Dclose(did2);
-        H5Gclose(gid);
+        H5Dclose(did);
         H5Fclose(fid);
         H5Pclose(fapl);
     } H5E_END_TRY;
 
-} /* gen_latest() */
+} /* gen_edge() */
+
 
 /*
- * Function: gen_non() 
+ * Function: gen_ext() 
  *
- * Create a file with SWMR write+non-latest-format--this will result in v3 superbock+latest version support:
- *	1) 1 chunked dataset with extensible array chunk indexing type (without data)
- *	2) 1 chunked dataset with version 2 B-tree chunk indexing type (with data)
- * Re-open the file with write+non-latest-format and create:
- *	3) 1 chunked dataset with version 2 B-tree chunk indexing type (without data)
- * 	4) 1 chunked dataset with extensible array indexing type (with data)
- *	5) 1 non-chunked dataset
+ * Create a file with/without latest format with:
+ *	1) 1 contiguous dataset (without data)
+ *	2) 2 chunked datasets with extensible array chunk indexing type (with/without data)
+ *	3) 2 chunked datasets with version 2 B-tree chunk indexing type (with/without data)
+ *	4) 2 chunked datasets with fixed array chunk indexing type (with/without data)
+ *	5) 2 chunked datasets with implicit array chunk indexing type (with/without data)
+ * It will create the file with/without messages in the superblock extension depending
+ * on the parameter "what".
  */
 static void
-gen_non(const char *fname)
+gen_ext(const char *fname, unsigned new, unsigned what)
 {
-    hid_t	fid = -1;		/* file id */
-    hid_t	fcpl = -1;		/* file creation property list */
-    hid_t	gid = -1;		/* group id */
+    hid_t	fid = -1;	 	/* file id */
+    hid_t	fapl = -1;	       	/* file access property list */
+    hid_t	fcpl = -1;	       	/* file creation property list */
+    hid_t	gid = -1;	       	/* group id */
     hid_t   	sid = -1;       	/* space id */
-    hid_t	dcpl = -1;		/* dataset creation property id */
+    hid_t	dcpl = -1;	    	/* dataset creation property id */
     hid_t	did1 = -1, did2 = -1;	/* dataset id */
     hsize_t 	dims1[1] = {10};     	/* dataset dimension */
     hsize_t 	dims2[2] = {4, 6};     	/* dataset dimension */
@@ -383,43 +409,75 @@ gen_non(const char *fname)
     int		i;		    	/* local index variable */
     int     	buf[24];            	/* data buffer */
 
-    if((fcpl = H5Pcreate(H5P_FILE_CREATE)) < 0)
-        goto error;
-    if(H5Pset_shared_mesg_nindexes(fcpl, 4) < 0)
-        goto error;
-    if(H5Pset_istore_k(fcpl, 64) < 0)
-        goto error;
+    if((fapl = H5Pcreate(H5P_FILE_ACCESS)) < 0)
+	goto error;
 
-    /* Create a new file with SWMR_WRITE + non-latest-format */
-    if((fid = H5Fcreate(fname, H5F_ACC_TRUNC|H5F_ACC_SWMR_WRITE, fcpl, H5P_DEFAULT)) < 0)
+    if(new) {
+	/* Create a new format file */
+	if(H5Pset_libver_bounds(fapl, H5F_LIBVER_LATEST, H5F_LIBVER_LATEST) < 0)
+	    goto error;
+    }
+
+    /* Create a file creation property list */
+    fcpl = H5Pcreate(H5P_FILE_CREATE);
+
+    /* Generate messages that might be placed in superblock extension */
+    switch(what) {
+	case 0:
+	    H5Pset_istore_k(fcpl, ISTORE_IK);
+	    break;
+	case 1:
+	    H5Pset_shared_mesg_nindexes(fcpl, 4);
+	    break;
+	case 2:
+	    H5Pset_file_space(fcpl, H5F_FILE_SPACE_ALL_PERSIST, (hsize_t)0);
+	    break;
+	case 3:
+	    H5Pset_istore_k(fcpl, ISTORE_IK);
+	    H5Pset_shared_mesg_nindexes(fcpl, 4);
+	    break;
+	case 4:
+	    H5Pset_istore_k(fcpl, ISTORE_IK);
+	    H5Pset_file_space(fcpl, 0, (hsize_t)2);
+	    break;
+	case 5:
+	    H5Pset_shared_mesg_nindexes(fcpl, 4);
+	    H5Pset_file_space(fcpl, H5F_FILE_SPACE_VFD, (hsize_t)0);
+	    break;
+	case 6:
+	    H5Pset_istore_k(fcpl, ISTORE_IK);
+	    H5Pset_shared_mesg_nindexes(fcpl, 4);
+	    H5Pset_file_space(fcpl, H5F_FILE_SPACE_AGGR_VFD, (hsize_t)0);
+	    break;
+	default:
+	    break;
+    }
+
+    /* Create the file */
+    if((fid = H5Fcreate(fname, H5F_ACC_TRUNC, fcpl, fapl)) < 0)
 	goto error;
 
     /* Create a group */
     if((gid = H5Gcreate2(fid, GROUP, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
 	goto error;
 
-    /* Create data */
-    for(i = 0; i < 24; i++)
-	buf[i] = i;
-
     /* Set chunk */
     if((dcpl = H5Pcreate(H5P_DATASET_CREATE)) < 0)
 	goto error;
     if(H5Pset_chunk(dcpl, 2, c_dims) < 0)
 	goto error;
 
+
     /* 
-     * Create a chunked dataset with extensible array chunk indexing type  (without data)
+     * Create a contiguous dataset 
      */
 
     /* Create dataspace */
-    max_dims[0] = 10;
-    max_dims[1] = H5S_UNLIMITED;
-    if((sid = H5Screate_simple(2, dims2, max_dims)) < 0)
+    if((sid = H5Screate_simple(1, dims1, NULL)) < 0)
 	goto error;
 
     /* Create the dataset */
-    if((did1  = H5Dcreate2(fid, DSET_NDATA_EA, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+    if((did1  = H5Dcreate2(fid, DSET_CONTIGUOUS, H5T_NATIVE_INT, sid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
 	goto error;
 
     /* Closing */
@@ -429,22 +487,29 @@ gen_non(const char *fname)
 	goto error;
 
     /* 
-     * Create a chunked dataset with version 2 B-tree chunk indexing type (with data)
+     * Create 2 chunked datasets with extensible array chunk indexing type 
+     * (one with data; one without data)
      */
 
     /* Create dataspace */
     max_dims[0] = 10;
-    max_dims[0] = H5S_UNLIMITED;
     max_dims[1] = H5S_UNLIMITED;
     if((sid = H5Screate_simple(2, dims2, max_dims)) < 0)
 	goto error;
 
-    /* Create the dataset */
-    if((did1  = H5Dcreate2(gid, DSET_BT2, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+    /* Create the 2 datasets */
+    if((did1  = H5Dcreate2(gid, DSET_NDATA_EA, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
 	goto error;
 
-    /* Write to the dataset */
-    if(H5Dwrite(did1, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf) < 0)
+    if((did2  = H5Dcreate2(fid, DSET_EA, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+	goto error;
+
+    /* Create data */
+    for(i = 0; i < 24; i++)
+	buf[i] = i;
+
+    /* Write to one dataset */
+    if(H5Dwrite(did2, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf) < 0)
 	goto error;
 
     /* Closing */
@@ -452,61 +517,61 @@ gen_non(const char *fname)
 	goto error;
     if(H5Dclose(did1) < 0)
 	goto error;
-    if(H5Pclose(dcpl) < 0)
-	goto error;
-    if(H5Gclose(gid) < 0)
-	goto error;
-    if(H5Fclose(fid) < 0)
-	goto error;
-
-    /* Re-open the file with old format */
-    if((fid = H5Fopen(fname, H5F_ACC_RDWR, H5P_DEFAULT)) < 0)
+    if(H5Dclose(did2) < 0)
 	goto error;
 
-    /* Open the group */
-    if((gid = H5Gopen2(fid, GROUP, H5P_DEFAULT)) < 0)
-	goto error;
 
-    /*
-     * Create a dataset with version 2 B-btree chunk indexing type (without data)
+    /* 
+     * Create 2 chunked datasets with version 2 B-tree chunk indexing type 
+     * (one with data; one without data)
      */
 
-    /* Set chunk */
-    if((dcpl = H5Pcreate(H5P_DATASET_CREATE)) < 0)
-	goto error;
-    if(H5Pset_chunk(dcpl, 2, c_dims) < 0)
-	goto error;
-
     /* Create dataspace */
+    max_dims[0] = 10;
     max_dims[0] = H5S_UNLIMITED;
     max_dims[1] = H5S_UNLIMITED;
     if((sid = H5Screate_simple(2, dims2, max_dims)) < 0)
 	goto error;
 
-    /* Create the dataset */
-    if((did1 = H5Dcreate2(fid, DSET_NDATA_BT2, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+    /* Create the 2 datasets */
+    if((did1  = H5Dcreate2(fid, DSET_NDATA_BT2, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
 	goto error;
 
-    /* Close the dataspace */
+    if((did2  = H5Dcreate2(gid, DSET_BT2, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+	goto error;
+
+    /* Write to one dataset */
+    if(H5Dwrite(did2, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf) < 0)
+	goto error;
+
+    /* Closing */
     if(H5Sclose(sid) < 0)
 	goto error;
+    if(H5Dclose(did1) < 0)
+	goto error;
+    if(H5Dclose(did2) < 0)
+	goto error;
 
     /*
-     * Create a dataset with version extensible array chunk indexing type (with data) in the group
+     * Create 2 chunked datasets with fixed array chunk indexing type 
+     * (one with data; one without data)
      */
 
     /* Create dataspace */
-    max_dims[0] = 10;
-    max_dims[1] = H5S_UNLIMITED;
+    max_dims[0] = 20;
+    max_dims[1] = 10;
     if((sid = H5Screate_simple(2, dims2, max_dims)) < 0)
 	goto error;
 
-    /* Create the dataset */
-    if((did2 = H5Dcreate2(gid, DSET_EA, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+    /* Create the datasets */
+    if((did1  = H5Dcreate2(fid, DSET_FA, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
+	goto error;
+
+    if((did2  = H5Dcreate2(gid, DSET_NDATA_FA, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
 	goto error;
 
     /* Write to the dataset */
-    if(H5Dwrite(did2, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf) < 0)
+    if(H5Dwrite(did1, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf) < 0)
 	goto error;
 
     /* Closing */
@@ -517,106 +582,42 @@ gen_non(const char *fname)
     if(H5Dclose(did2) < 0)
 	goto error;
 
+
     /* 
-     * Create a non-chunked dataset in the group
+     * Create 2 chunked datasets with implicit chunk indexing type 
+     * (one with data; one without data)
      */
 
     /* Create dataspace */
-    if((sid = H5Screate_simple(1, dims1, NULL)) < 0)
+    if((sid = H5Screate_simple(2, dims2, NULL)) < 0)
 	goto error;
 
-    /* Create the dataset */
-    if((did1  = H5Dcreate2(gid, DSET_NON_CHUNKED, H5T_NATIVE_INT, sid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+    /* Set early allocation */
+    if(H5Pset_alloc_time(dcpl, H5D_ALLOC_TIME_EARLY) < 0)
 	goto error;
 
-    /* Closing */
-    if(H5Sclose(sid) < 0)
-	goto error;
-    if(H5Dclose(did1) < 0)
+    /* Create the 2 datasets */
+    if((did1  = H5Dcreate2(fid, DSET_NONE, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
 	goto error;
 
-    if(H5Gclose(gid) < 0)
-	goto error;
-    if(H5Fclose(fid) < 0)
-	goto error;
-    if(H5Pclose(dcpl) < 0)
+    if((did2  = H5Dcreate2(gid, DSET_NDATA_NONE, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
 	goto error;
 
-error:
-    H5E_BEGIN_TRY {
-        H5Pclose(dcpl);
-        H5Sclose(sid);
-        H5Dclose(did1);
-        H5Dclose(did2);
-        H5Gclose(gid);
-        H5Fclose(fid);
-    } H5E_END_TRY;
-
-} /* gen_non() */
-
-/*
- * Function: gen_edge() 
- *
- * Create a file with write+latest-format--this will result in v3 superblock+latest version support:
- *	A dataset: chunked, filtered, H5D_CHUNK_DONT_FILTER_PARTIAL_CHUNKS enabled
- *	(i.e. the dataset does not filter partial edge chunks)
- */
-static void
-gen_edge(const char *fname)
-{
-    hid_t	fid = -1;	    	/* file id */
-    hid_t	fapl = -1;	       	/* file access property list */
-    hid_t   	sid = -1;       	/* dataspace id */
-    hid_t	dcpl = -1;	    	/* dataset creation property id */
-    hid_t	did = -1;		/* dataset id */
-    hsize_t 	dims2[2] = {12, 6};	/* Dataset dimensions */
-    hsize_t 	c_dims[2] = {5, 5};	/* Chunk dimensions */
-    float 	buf[12][6];            	/* Buffer for writing data */
-    int		i, j;		    	/* local index variable */
-
-    /* Create a new format file */
-    if((fapl = H5Pcreate(H5P_FILE_ACCESS)) < 0)
-	goto error;
-    if(H5Pset_libver_bounds(fapl, H5F_LIBVER_LATEST, H5F_LIBVER_LATEST) < 0)
-	goto error;
-    if((fid = H5Fcreate(fname, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0)
+    /* Write to one dataset */
+    if(H5Dwrite(did1, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf) < 0)
 	goto error;
 
-    /* Set chunk, filter, no-filter-edge-chunk */
-    if((dcpl = H5Pcreate(H5P_DATASET_CREATE)) < 0)
+    /* Closing */
+    if(H5Dclose(did1) < 0)
 	goto error;
-    if(H5Pset_chunk(dcpl, 2, c_dims) < 0)
+    if(H5Dclose(did2) < 0)
 	goto error;
-    if(H5Pset_deflate(dcpl, 9) < 0)
-        goto error;
-    if(H5Pset_chunk_opts(dcpl, H5D_CHUNK_DONT_FILTER_PARTIAL_CHUNKS) < 0)
-        goto error;
-
-    /* Create dataspace */
-    if((sid = H5Screate_simple(2, dims2, NULL)) < 0)
-        goto error;
-
-    /* Create the dataset */
-    if((did = H5Dcreate2(fid, DSET_EDGE, H5T_NATIVE_FLOAT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0)
-        goto error;
-
-    /* Create data */
-    for (i = 0; i< 12; i++)
-        for (j = 0; j< 6; j++)
-            buf[i][j] = 100.0F;
-
-    /* Write to the dataset */
-    if(H5Dwrite(did, H5T_NATIVE_FLOAT, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf) < 0)
+    if(H5Sclose(sid) < 0)
 	goto error;
 
-    /* Closing */
     if(H5Pclose(dcpl) < 0)
 	goto error;
-    if(H5Sclose(sid) < 0)
-	goto error;
-    if(H5Dclose(did) < 0)
-	goto error;
-    if(H5Pclose(fapl) < 0)
+    if(H5Gclose(gid) < 0)
 	goto error;
     if(H5Fclose(fid) < 0)
 	goto error;
@@ -625,25 +626,39 @@ error:
     H5E_BEGIN_TRY {
         H5Pclose(dcpl);
         H5Sclose(sid);
-        H5Dclose(did);
+        H5Dclose(did1);
+        H5Dclose(did2);
+        H5Gclose(gid);
         H5Fclose(fid);
         H5Pclose(fapl);
+        H5Pclose(fcpl);
     } H5E_END_TRY;
 
-} /* gen_edge() */
+} /* gen_ext() */
 
 int main(void)
 {
-    /* Generate an old format file with v1 superbock */
-    gen_old(OLD_V1_FILE);
-
-    /* Generate a latest-format file with v3 superblock */
-    gen_latest(LATEST_V3_FILE);
+    unsigned i, new;
 
     /* Generate a non-latest-format file with v3 superblock */
     gen_non(NON_V3_FILE);
 
-    /* Generate a new format file with a no-filter-edge-chunk dataset for testing */
+    /* Generate a new format file with a no-filter-edge-chunk dataset */
     gen_edge(EDGE_V3_FILE);
+
+    /* Generate old/new format file with/without messages in the superblock extension */
+    for(new = FALSE; new <= TRUE; new++) {
+	for(i = 0; i < 8; i++) {
+            char filename[50];
+
+	    HDmemset(filename, 0, sizeof(filename));
+	    if(!new)
+		HDstrcat(filename, "old_");
+	    HDstrcat(filename, FILENAME[i]);
+
+	    gen_ext(filename, new, i);
+	}
+    } /* end for new */
+
     return 0;
 }
diff --git a/tools/h5format_convert/h5format_convert.c b/tools/h5format_convert/h5format_convert.c
index a80e332..105ac5d 100644
--- a/tools/h5format_convert/h5format_convert.c
+++ b/tools/h5format_convert/h5format_convert.c
@@ -88,16 +88,20 @@ static void usage(const char *prog)
 	printf("Examples of use:\n");
 	printf("\n");
 	printf("h5format_convert -d /group/dataset file_name\n");
-	printf("  Convert the chunk indexing type to version 1 B-tree\n");
-	printf("  for the chunked dataset </group/dataset> in the HDF5 file <file_name>.\n");
+	printf("  Convert the dataset </group/dataset> in the HDF5 file <file_name>:\n");
+	printf("    a. chunked dataset: convert the chunk indexing type to version 1 B-tree\n");
+	printf("    b. compact/contiguous dataset: downgrade the layout version to 3\n");
+	printf("    c. virtual dataset: no action\n");
 	printf("\n");
 	printf("h5format_convert file_name\n");
-	printf("  Convert the chunk indexing type to version 1 B-tree\n");
-	printf("  for all the chunked datasets in the HDF5 file <file_name>.\n");
+	printf("  Convert all datasets in the HDF5 file <file_name>:\n");
+	printf("    a. chunked dataset: convert the chunk indexing type to version 1 B-tree\n");
+	printf("    b. compact/contiguous dataset: downgrade the layout version to 3\n");
+	printf("    c. virtual dataset: no action\n");
 	printf("\n");
 	printf("h5format_convert -n -d /group/dataset file_name\n");
 	printf("  Go through all the steps except the actual conversion when \n");
-	printf("  converting the chunked dataset </group/dataset> in the HDF5 file <file_name>.\n");
+	printf("  converting the dataset </group/dataset> in the HDF5 file <file_name>.\n");
 } /* usage() */
 
 /*-------------------------------------------------------------------------
@@ -200,11 +204,15 @@ leave(int ret)
 /*-------------------------------------------------------------------------
  * Function: convert()
  *
- * Purpose: To change the chunk indexing type for the dataset to version 1 B-tree.
- *	    -- the dataset has to be chunked
- *	    -- the dataset's chunk indexing type is not already version 1 B-tree.
- *	    If the above conditions are not fulfilled, the tool will not perform
- *	    the conversion but will exit with success.
+ * Purpose: To downgrade a dataset's indexing type or layout version:
+ *		For chunked:
+ *		  Downgrade the chunk indexing type to version 1 B-tree
+ *	    	  If type is already version 1 B-tree, no further action
+ *		For compact/contiguous:
+ *		  Downgrade the layout version from 4 to 3
+ *		  If version is already <= 3, no further action
+ *		For virtual:
+ *		  No further action
  *
  * Return: Success: 0
  *  	   Failure: 1
@@ -244,34 +252,49 @@ convert(hid_t fid, const char *dname)
     } else if(verbose_g)
 	printf("Retrieve the dataset's layout\n");
 
-    /* No further action if not a chunked dataset */
-    if(layout_type != H5D_CHUNKED) {
-	if(verbose_g)
-	    printf("Dataset is not chunked: no further action\n");
-	h5tools_setstatus(EXIT_SUCCESS);
-	goto done;
+    switch(layout_type) {
+	case H5D_CHUNKED:
+	    if(verbose_g)
+		printf("Dataset is a chunked dataset\n");
 
-    } else if(verbose_g)
-	printf("Verify the dataset is a chunked dataset\n");
+	    /* Get the dataset's chunk indexing type */
+	    if(H5Dget_chunk_index_type(did, &idx_type) < 0) {
+		error_msg("unable to get the chunk indexing type for \"%s\"\n", dname);
+		h5tools_setstatus(EXIT_FAILURE);
+		goto error;
+	    } else if(verbose_g)
+		printf("Retrieve the dataset's chunk indexing type\n");
 
-    /* Get the dataset's chunk indexing type */
-    if(H5Dget_chunk_index_type(did, &idx_type) < 0) {
-	error_msg("unable to get the chunk indexing type for \"%s\"\n", dname);
-	h5tools_setstatus(EXIT_FAILURE);
-	goto error;
+	    if(idx_type == H5D_CHUNK_IDX_BTREE) {
+		if(verbose_g)
+		    printf("Dataset's chunk indexing type is already version 1 B-tree: no further action\n");
+		h5tools_setstatus(EXIT_SUCCESS);
+		goto done;
+	    } else if (verbose_g)
+		printf("Dataset's chunk indexing type is not version 1 B-tree\n");
+	    break;
 
-    } else if(verbose_g)
-	printf("Retrieve the dataset's chunk indexing type\n");
+	case H5D_CONTIGUOUS:
+	    if(verbose_g)
+		printf("Dataset is a contiguous dataset: downgrade layout version as needed\n");
+	    break;
 
-    /* No further action if the chunk indexing type is already version 1 B-tree */
-    if(idx_type == H5D_CHUNK_IDX_BTREE) {
-	if(verbose_g)
-	    printf("Chunk indexing type is already version 1 B-tree: no further action\n");
-	h5tools_setstatus(EXIT_SUCCESS);
-	goto done;
+        case H5D_COMPACT:
+	    if(verbose_g)
+		printf("Dataset is a compact dataset: downgrade layout version as needed\n");
+	    break;
+
+        case H5D_VIRTUAL:
+	    if(verbose_g)
+		printf("No further action for virtual dataset\n");
+	    goto done;
 
-    } else if (verbose_g)
-	printf("Verify the dataset's chunk indexing type is not version 1 B-tree\n");
+	default:
+	    error_msg("unknown layout type for \"%s\"\n", dname);
+	    h5tools_setstatus(EXIT_FAILURE);
+	    goto error;
+
+    } /* end switch */
 
     /* No further action if it is a noop */
     if(noop_g) {
@@ -284,12 +307,11 @@ convert(hid_t fid, const char *dname)
     if(verbose_g)
 	printf("Converting the dataset...\n");
 
-    /* Convert the dataset's chunk indexing type to version 1 B-tree */
+    /* Downgrade the dataset */
     if(H5Dformat_convert(did) < 0) {
-	error_msg("unable to convert chunk indexing for \"%s\"\n", dname);
+	error_msg("unable to downgrade dataset for \"%s\"\n", dname);
 	h5tools_setstatus(EXIT_FAILURE);
 	goto error;
-
     } else if(verbose_g)
 	printf("Done\n");
 
@@ -377,9 +399,6 @@ main(int argc, const char *argv[])
     H5E_auto2_t func;
     void *edata;
     hid_t fid = -1;
-    hid_t fcpl = -1;
-    H5F_file_space_type_t strategy;
-    hsize_t threshold;
 
     h5tools_setprogname(PROGRAMNAME);
     h5tools_setstatus(EXIT_SUCCESS);
@@ -408,28 +427,6 @@ main(int argc, const char *argv[])
     } else if(verbose_g)
 	printf("Open the file %s\n", fname_g);
 
-    /* A temporaray fix: 
-     * need to handle H5O_FSINFO_ID message when downgrade superblock version from 3 to 2 
-     */
-    if((fcpl = H5Fget_create_plist(fid)) < 0) {
-	error_msg("unable to get file creation property list for \"%s\"\n", fname_g);
-	h5tools_setstatus(EXIT_FAILURE);
-	goto done;
-    }
-    if(H5Pget_file_space(fcpl, &strategy, &threshold) < 0) {
-	error_msg("unable to get file space strategy/threshold\n");
-	h5tools_setstatus(EXIT_FAILURE);
-	goto done;
-    }
-    /* Check for non-default strategy/threshold: 
-     * --whether there is H5O_FSINFO_ID message in the superblock extension 
-     */
-    if(strategy != H5F_FILE_SPACE_ALL || threshold != 1) {
-	error_msg("unable to convert due to non-default file space strategy/threshold\n");
-	h5tools_setstatus(EXIT_FAILURE);
-	goto done;
-    }
-
     if(dset_g) { /* Convert a specified dataset in the file */
 	if(verbose_g)
 	    printf("Going to process dataset: %s...\n", dname_g);
@@ -443,16 +440,17 @@ main(int argc, const char *argv[])
     }
 
     if(verbose_g) {
-	if(noop_g) {
-            printf("Not processing the file's superblock version...\n");
-	    h5tools_setstatus(EXIT_SUCCESS);
-	    goto done;
-	}
-	printf("Processing the file's superblock version...\n");
+        if(noop_g) {
+            printf("Not processing the file's superblock...\n");
+            h5tools_setstatus(EXIT_SUCCESS);
+            goto done;
+        }
+        printf("Processing the file's superblock...\n");
     }
 
-    if(H5Fformat_convert_super(fid) < 0) {
-        error_msg("unable to convert file's superblock version\"%s\"\n", fname_g);
+    /* Process superblock */
+    if(H5Fformat_convert(fid) < 0) {
+        error_msg("unable to convert file's superblock\"%s\"\n", fname_g);
         h5tools_setstatus(EXIT_FAILURE);
         goto done;
     }
diff --git a/tools/h5format_convert/testfiles/h5fc_d_file.ddl b/tools/h5format_convert/testfiles/h5fc_d_file.ddl
index 3641a4f..ad7a2f4 100644
--- a/tools/h5format_convert/testfiles/h5fc_d_file.ddl
+++ b/tools/h5format_convert/testfiles/h5fc_d_file.ddl
@@ -9,14 +9,18 @@ usage: h5format_convert [OPTIONS] file_name
 Examples of use:
 
 h5format_convert -d /group/dataset file_name
-  Convert the chunk indexing type to version 1 B-tree
-  for the chunked dataset </group/dataset> in the HDF5 file <file_name>.
+  Convert the dataset </group/dataset> in the HDF5 file <file_name>:
+    a. chunked dataset: convert the chunk indexing type to version 1 B-tree
+    b. compact/contiguous dataset: downgrade the layout version to 3
+    c. virtual dataset: no action
 
 h5format_convert file_name
-  Convert the chunk indexing type to version 1 B-tree
-  for all the chunked datasets in the HDF5 file <file_name>.
+  Convert all datasets in the HDF5 file <file_name>:
+    a. chunked dataset: convert the chunk indexing type to version 1 B-tree
+    b. compact/contiguous dataset: downgrade the layout version to 3
+    c. virtual dataset: no action
 
 h5format_convert -n -d /group/dataset file_name
   Go through all the steps except the actual conversion when 
-  converting the chunked dataset </group/dataset> in the HDF5 file <file_name>.
+  converting the dataset </group/dataset> in the HDF5 file <file_name>.
 h5format_convert error: missing file name
diff --git a/tools/h5format_convert/testfiles/h5fc_dname.ddl b/tools/h5format_convert/testfiles/h5fc_dname.ddl
index c391764..0de42cb 100644
--- a/tools/h5format_convert/testfiles/h5fc_dname.ddl
+++ b/tools/h5format_convert/testfiles/h5fc_dname.ddl
@@ -9,14 +9,18 @@ usage: h5format_convert [OPTIONS] file_name
 Examples of use:
 
 h5format_convert -d /group/dataset file_name
-  Convert the chunk indexing type to version 1 B-tree
-  for the chunked dataset </group/dataset> in the HDF5 file <file_name>.
+  Convert the dataset </group/dataset> in the HDF5 file <file_name>:
+    a. chunked dataset: convert the chunk indexing type to version 1 B-tree
+    b. compact/contiguous dataset: downgrade the layout version to 3
+    c. virtual dataset: no action
 
 h5format_convert file_name
-  Convert the chunk indexing type to version 1 B-tree
-  for all the chunked datasets in the HDF5 file <file_name>.
+  Convert all datasets in the HDF5 file <file_name>:
+    a. chunked dataset: convert the chunk indexing type to version 1 B-tree
+    b. compact/contiguous dataset: downgrade the layout version to 3
+    c. virtual dataset: no action
 
 h5format_convert -n -d /group/dataset file_name
   Go through all the steps except the actual conversion when 
-  converting the chunked dataset </group/dataset> in the HDF5 file <file_name>.
+  converting the dataset </group/dataset> in the HDF5 file <file_name>.
 h5format_convert error: No dataset name
diff --git a/tools/h5format_convert/testfiles/h5fc_ext1_f.ddl b/tools/h5format_convert/testfiles/h5fc_ext1_f.ddl
new file mode 100644
index 0000000..fb5192d
--- /dev/null
+++ b/tools/h5format_convert/testfiles/h5fc_ext1_f.ddl
@@ -0,0 +1,58 @@
+HDF5 "./testfiles/tmp.h5" {
+SUPER_BLOCK {
+   SUPERBLOCK_VERSION 2
+   FREELIST_VERSION 0
+   SYMBOLTABLE_VERSION 0
+   OBJECTHEADER_VERSION 0
+   OFFSET_SIZE 8
+   LENGTH_SIZE 8
+   BTREE_RANK 16
+   BTREE_LEAF 4
+   ISTORE_K 32
+   FILE_SPACE_STRATEGY H5F_FILE_SPACE_ALL
+   FREE_SPACE_THRESHOLD 1
+   USER_BLOCK {
+      USERBLOCK_SIZE 0
+   }
+}
+GROUP "/" {
+   DATASET "DSET_CONTIGUOUS" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 10 ) / ( 10 ) }
+   }
+   DATASET "DSET_EA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_FA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+   }
+   DATASET "DSET_NDATA_BT2" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_NONE" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+   }
+   GROUP "GROUP" {
+      DATASET "DSET_BT2" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_EA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_FA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+      }
+      DATASET "DSET_NDATA_NONE" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+      }
+   }
+}
+}
diff --git a/tools/h5format_convert/testfiles/h5fc_ext1_f.h5 b/tools/h5format_convert/testfiles/h5fc_ext1_f.h5
new file mode 100644
index 0000000..b5c5867
--- /dev/null
+++ b/tools/h5format_convert/testfiles/h5fc_ext1_f.h5
diff --git a/tools/h5format_convert/testfiles/h5fc_ext1_i.ddl b/tools/h5format_convert/testfiles/h5fc_ext1_i.ddl
new file mode 100644
index 0000000..2fff4ac
--- /dev/null
+++ b/tools/h5format_convert/testfiles/h5fc_ext1_i.ddl
@@ -0,0 +1,58 @@
+HDF5 "./testfiles/tmp.h5" {
+SUPER_BLOCK {
+   SUPERBLOCK_VERSION 2
+   FREELIST_VERSION 0
+   SYMBOLTABLE_VERSION 0
+   OBJECTHEADER_VERSION 0
+   OFFSET_SIZE 8
+   LENGTH_SIZE 8
+   BTREE_RANK 16
+   BTREE_LEAF 4
+   ISTORE_K 64
+   FILE_SPACE_STRATEGY H5F_FILE_SPACE_ALL
+   FREE_SPACE_THRESHOLD 1
+   USER_BLOCK {
+      USERBLOCK_SIZE 0
+   }
+}
+GROUP "/" {
+   DATASET "DSET_CONTIGUOUS" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 10 ) / ( 10 ) }
+   }
+   DATASET "DSET_EA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_FA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+   }
+   DATASET "DSET_NDATA_BT2" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_NONE" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+   }
+   GROUP "GROUP" {
+      DATASET "DSET_BT2" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_EA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_FA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+      }
+      DATASET "DSET_NDATA_NONE" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+      }
+   }
+}
+}
diff --git a/tools/h5format_convert/testfiles/h5fc_ext1_i.h5 b/tools/h5format_convert/testfiles/h5fc_ext1_i.h5
new file mode 100644
index 0000000..960a8d5
--- /dev/null
+++ b/tools/h5format_convert/testfiles/h5fc_ext1_i.h5
diff --git a/tools/h5format_convert/testfiles/h5fc_ext1_s.ddl b/tools/h5format_convert/testfiles/h5fc_ext1_s.ddl
new file mode 100644
index 0000000..fb5192d
--- /dev/null
+++ b/tools/h5format_convert/testfiles/h5fc_ext1_s.ddl
@@ -0,0 +1,58 @@
+HDF5 "./testfiles/tmp.h5" {
+SUPER_BLOCK {
+   SUPERBLOCK_VERSION 2
+   FREELIST_VERSION 0
+   SYMBOLTABLE_VERSION 0
+   OBJECTHEADER_VERSION 0
+   OFFSET_SIZE 8
+   LENGTH_SIZE 8
+   BTREE_RANK 16
+   BTREE_LEAF 4
+   ISTORE_K 32
+   FILE_SPACE_STRATEGY H5F_FILE_SPACE_ALL
+   FREE_SPACE_THRESHOLD 1
+   USER_BLOCK {
+      USERBLOCK_SIZE 0
+   }
+}
+GROUP "/" {
+   DATASET "DSET_CONTIGUOUS" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 10 ) / ( 10 ) }
+   }
+   DATASET "DSET_EA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_FA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+   }
+   DATASET "DSET_NDATA_BT2" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_NONE" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+   }
+   GROUP "GROUP" {
+      DATASET "DSET_BT2" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_EA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_FA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+      }
+      DATASET "DSET_NDATA_NONE" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+      }
+   }
+}
+}
diff --git a/tools/h5format_convert/testfiles/h5fc_ext1_s.h5 b/tools/h5format_convert/testfiles/h5fc_ext1_s.h5
new file mode 100644
index 0000000..103bde6
--- /dev/null
+++ b/tools/h5format_convert/testfiles/h5fc_ext1_s.h5
diff --git a/tools/h5format_convert/testfiles/h5fc_ext2_if.ddl b/tools/h5format_convert/testfiles/h5fc_ext2_if.ddl
new file mode 100644
index 0000000..2fff4ac
--- /dev/null
+++ b/tools/h5format_convert/testfiles/h5fc_ext2_if.ddl
@@ -0,0 +1,58 @@
+HDF5 "./testfiles/tmp.h5" {
+SUPER_BLOCK {
+   SUPERBLOCK_VERSION 2
+   FREELIST_VERSION 0
+   SYMBOLTABLE_VERSION 0
+   OBJECTHEADER_VERSION 0
+   OFFSET_SIZE 8
+   LENGTH_SIZE 8
+   BTREE_RANK 16
+   BTREE_LEAF 4
+   ISTORE_K 64
+   FILE_SPACE_STRATEGY H5F_FILE_SPACE_ALL
+   FREE_SPACE_THRESHOLD 1
+   USER_BLOCK {
+      USERBLOCK_SIZE 0
+   }
+}
+GROUP "/" {
+   DATASET "DSET_CONTIGUOUS" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 10 ) / ( 10 ) }
+   }
+   DATASET "DSET_EA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_FA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+   }
+   DATASET "DSET_NDATA_BT2" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_NONE" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+   }
+   GROUP "GROUP" {
+      DATASET "DSET_BT2" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_EA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_FA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+      }
+      DATASET "DSET_NDATA_NONE" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+      }
+   }
+}
+}
diff --git a/tools/h5format_convert/testfiles/h5fc_ext2_if.h5 b/tools/h5format_convert/testfiles/h5fc_ext2_if.h5
new file mode 100644
index 0000000..88e42e7
--- /dev/null
+++ b/tools/h5format_convert/testfiles/h5fc_ext2_if.h5
diff --git a/tools/h5format_convert/testfiles/h5fc_ext2_is.ddl b/tools/h5format_convert/testfiles/h5fc_ext2_is.ddl
new file mode 100644
index 0000000..2fff4ac
--- /dev/null
+++ b/tools/h5format_convert/testfiles/h5fc_ext2_is.ddl
@@ -0,0 +1,58 @@
+HDF5 "./testfiles/tmp.h5" {
+SUPER_BLOCK {
+   SUPERBLOCK_VERSION 2
+   FREELIST_VERSION 0
+   SYMBOLTABLE_VERSION 0
+   OBJECTHEADER_VERSION 0
+   OFFSET_SIZE 8
+   LENGTH_SIZE 8
+   BTREE_RANK 16
+   BTREE_LEAF 4
+   ISTORE_K 64
+   FILE_SPACE_STRATEGY H5F_FILE_SPACE_ALL
+   FREE_SPACE_THRESHOLD 1
+   USER_BLOCK {
+      USERBLOCK_SIZE 0
+   }
+}
+GROUP "/" {
+   DATASET "DSET_CONTIGUOUS" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 10 ) / ( 10 ) }
+   }
+   DATASET "DSET_EA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_FA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+   }
+   DATASET "DSET_NDATA_BT2" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_NONE" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+   }
+   GROUP "GROUP" {
+      DATASET "DSET_BT2" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_EA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_FA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+      }
+      DATASET "DSET_NDATA_NONE" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+      }
+   }
+}
+}
diff --git a/tools/h5format_convert/testfiles/h5fc_ext2_is.h5 b/tools/h5format_convert/testfiles/h5fc_ext2_is.h5
new file mode 100644
index 0000000..4d76436
--- /dev/null
+++ b/tools/h5format_convert/testfiles/h5fc_ext2_is.h5
diff --git a/tools/h5format_convert/testfiles/h5fc_ext2_sf.ddl b/tools/h5format_convert/testfiles/h5fc_ext2_sf.ddl
new file mode 100644
index 0000000..fb5192d
--- /dev/null
+++ b/tools/h5format_convert/testfiles/h5fc_ext2_sf.ddl
@@ -0,0 +1,58 @@
+HDF5 "./testfiles/tmp.h5" {
+SUPER_BLOCK {
+   SUPERBLOCK_VERSION 2
+   FREELIST_VERSION 0
+   SYMBOLTABLE_VERSION 0
+   OBJECTHEADER_VERSION 0
+   OFFSET_SIZE 8
+   LENGTH_SIZE 8
+   BTREE_RANK 16
+   BTREE_LEAF 4
+   ISTORE_K 32
+   FILE_SPACE_STRATEGY H5F_FILE_SPACE_ALL
+   FREE_SPACE_THRESHOLD 1
+   USER_BLOCK {
+      USERBLOCK_SIZE 0
+   }
+}
+GROUP "/" {
+   DATASET "DSET_CONTIGUOUS" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 10 ) / ( 10 ) }
+   }
+   DATASET "DSET_EA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_FA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+   }
+   DATASET "DSET_NDATA_BT2" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_NONE" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+   }
+   GROUP "GROUP" {
+      DATASET "DSET_BT2" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_EA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_FA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+      }
+      DATASET "DSET_NDATA_NONE" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+      }
+   }
+}
+}
diff --git a/tools/h5format_convert/testfiles/h5fc_ext2_sf.h5 b/tools/h5format_convert/testfiles/h5fc_ext2_sf.h5
new file mode 100644
index 0000000..c59a3ca
--- /dev/null
+++ b/tools/h5format_convert/testfiles/h5fc_ext2_sf.h5
diff --git a/tools/h5format_convert/testfiles/h5fc_ext3_isf.ddl b/tools/h5format_convert/testfiles/h5fc_ext3_isf.ddl
new file mode 100644
index 0000000..2fff4ac
--- /dev/null
+++ b/tools/h5format_convert/testfiles/h5fc_ext3_isf.ddl
@@ -0,0 +1,58 @@
+HDF5 "./testfiles/tmp.h5" {
+SUPER_BLOCK {
+   SUPERBLOCK_VERSION 2
+   FREELIST_VERSION 0
+   SYMBOLTABLE_VERSION 0
+   OBJECTHEADER_VERSION 0
+   OFFSET_SIZE 8
+   LENGTH_SIZE 8
+   BTREE_RANK 16
+   BTREE_LEAF 4
+   ISTORE_K 64
+   FILE_SPACE_STRATEGY H5F_FILE_SPACE_ALL
+   FREE_SPACE_THRESHOLD 1
+   USER_BLOCK {
+      USERBLOCK_SIZE 0
+   }
+}
+GROUP "/" {
+   DATASET "DSET_CONTIGUOUS" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 10 ) / ( 10 ) }
+   }
+   DATASET "DSET_EA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_FA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+   }
+   DATASET "DSET_NDATA_BT2" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_NONE" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+   }
+   GROUP "GROUP" {
+      DATASET "DSET_BT2" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_EA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_FA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+      }
+      DATASET "DSET_NDATA_NONE" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+      }
+   }
+}
+}
diff --git a/tools/h5format_convert/testfiles/h5fc_ext3_isf.h5 b/tools/h5format_convert/testfiles/h5fc_ext3_isf.h5
new file mode 100644
index 0000000..d00fc55
--- /dev/null
+++ b/tools/h5format_convert/testfiles/h5fc_ext3_isf.h5
diff --git a/tools/h5format_convert/testfiles/h5fc_latest_v3.h5 b/tools/h5format_convert/testfiles/h5fc_ext_none.h5
index f7de743..b1b1553 100644
--- a/tools/h5format_convert/testfiles/h5fc_latest_v3.h5
+++ b/tools/h5format_convert/testfiles/h5fc_ext_none.h5
diff --git a/tools/h5format_convert/testfiles/h5fc_help.ddl b/tools/h5format_convert/testfiles/h5fc_help.ddl
index 9081ab8..aef8c63 100644
--- a/tools/h5format_convert/testfiles/h5fc_help.ddl
+++ b/tools/h5format_convert/testfiles/h5fc_help.ddl
@@ -9,13 +9,17 @@ usage: h5format_convert [OPTIONS] file_name
 Examples of use:
 
 h5format_convert -d /group/dataset file_name
-  Convert the chunk indexing type to version 1 B-tree
-  for the chunked dataset </group/dataset> in the HDF5 file <file_name>.
+  Convert the dataset </group/dataset> in the HDF5 file <file_name>:
+    a. chunked dataset: convert the chunk indexing type to version 1 B-tree
+    b. compact/contiguous dataset: downgrade the layout version to 3
+    c. virtual dataset: no action
 
 h5format_convert file_name
-  Convert the chunk indexing type to version 1 B-tree
-  for all the chunked datasets in the HDF5 file <file_name>.
+  Convert all datasets in the HDF5 file <file_name>:
+    a. chunked dataset: convert the chunk indexing type to version 1 B-tree
+    b. compact/contiguous dataset: downgrade the layout version to 3
+    c. virtual dataset: no action
 
 h5format_convert -n -d /group/dataset file_name
   Go through all the steps except the actual conversion when 
-  converting the chunked dataset </group/dataset> in the HDF5 file <file_name>.
+  converting the dataset </group/dataset> in the HDF5 file <file_name>.
diff --git a/tools/h5format_convert/testfiles/h5fc_non_v3.h5 b/tools/h5format_convert/testfiles/h5fc_non_v3.h5
index b1bffa8..af2e8c4 100644
--- a/tools/h5format_convert/testfiles/h5fc_non_v3.h5
+++ b/tools/h5format_convert/testfiles/h5fc_non_v3.h5
diff --git a/tools/h5format_convert/testfiles/h5fc_nooption.ddl b/tools/h5format_convert/testfiles/h5fc_nooption.ddl
index 9081ab8..aef8c63 100644
--- a/tools/h5format_convert/testfiles/h5fc_nooption.ddl
+++ b/tools/h5format_convert/testfiles/h5fc_nooption.ddl
@@ -9,13 +9,17 @@ usage: h5format_convert [OPTIONS] file_name
 Examples of use:
 
 h5format_convert -d /group/dataset file_name
-  Convert the chunk indexing type to version 1 B-tree
-  for the chunked dataset </group/dataset> in the HDF5 file <file_name>.
+  Convert the dataset </group/dataset> in the HDF5 file <file_name>:
+    a. chunked dataset: convert the chunk indexing type to version 1 B-tree
+    b. compact/contiguous dataset: downgrade the layout version to 3
+    c. virtual dataset: no action
 
 h5format_convert file_name
-  Convert the chunk indexing type to version 1 B-tree
-  for all the chunked datasets in the HDF5 file <file_name>.
+  Convert all datasets in the HDF5 file <file_name>:
+    a. chunked dataset: convert the chunk indexing type to version 1 B-tree
+    b. compact/contiguous dataset: downgrade the layout version to 3
+    c. virtual dataset: no action
 
 h5format_convert -n -d /group/dataset file_name
   Go through all the steps except the actual conversion when 
-  converting the chunked dataset </group/dataset> in the HDF5 file <file_name>.
+  converting the dataset </group/dataset> in the HDF5 file <file_name>.
diff --git a/tools/h5format_convert/testfiles/h5fc_v1.h5 b/tools/h5format_convert/testfiles/h5fc_v1.h5
deleted file mode 100644
index d3d66f8..0000000
--- a/tools/h5format_convert/testfiles/h5fc_v1.h5
+++ /dev/null
diff --git a/tools/h5format_convert/testfiles/h5fc_v_all.ddl b/tools/h5format_convert/testfiles/h5fc_v_all.ddl
index 5a35c55..5e7365d 100644
--- a/tools/h5format_convert/testfiles/h5fc_v_all.ddl
+++ b/tools/h5format_convert/testfiles/h5fc_v_all.ddl
@@ -1,27 +1,77 @@
 Process command line options
 Open the file tmp.h5
 Processing all datasets in the file...
-Going to process dataset:/DSET_NDATA_BT1...
+Going to process dataset:/DSET_CONTIGUOUS...
 Open the dataset
 Retrieve the dataset's layout
-Verify the dataset is a chunked dataset
+Dataset is a contiguous dataset: downgrade layout version as needed
+Converting the dataset...
+Done
+Close the dataset
+Close the dataset creation property list
+Going to process dataset:/DSET_EA...
+Open the dataset
+Retrieve the dataset's layout
+Dataset is a chunked dataset
+Retrieve the dataset's chunk indexing type
+Dataset's chunk indexing type is already version 1 B-tree: no further action
+Close the dataset
+Close the dataset creation property list
+Going to process dataset:/DSET_FA...
+Open the dataset
+Retrieve the dataset's layout
+Dataset is a chunked dataset
+Retrieve the dataset's chunk indexing type
+Dataset's chunk indexing type is already version 1 B-tree: no further action
+Close the dataset
+Close the dataset creation property list
+Going to process dataset:/DSET_NDATA_BT2...
+Open the dataset
+Retrieve the dataset's layout
+Dataset is a chunked dataset
+Retrieve the dataset's chunk indexing type
+Dataset's chunk indexing type is already version 1 B-tree: no further action
+Close the dataset
+Close the dataset creation property list
+Going to process dataset:/DSET_NONE...
+Open the dataset
+Retrieve the dataset's layout
+Dataset is a chunked dataset
 Retrieve the dataset's chunk indexing type
-Chunk indexing type is already version 1 B-tree: no further action
+Dataset's chunk indexing type is already version 1 B-tree: no further action
 Close the dataset
 Close the dataset creation property list
-Going to process dataset:/DSET_NON_CHUNKED...
+Going to process dataset:/GROUP/DSET_BT2...
 Open the dataset
 Retrieve the dataset's layout
-Dataset is not chunked: no further action
+Dataset is a chunked dataset
+Retrieve the dataset's chunk indexing type
+Dataset's chunk indexing type is already version 1 B-tree: no further action
+Close the dataset
+Close the dataset creation property list
+Going to process dataset:/GROUP/DSET_NDATA_EA...
+Open the dataset
+Retrieve the dataset's layout
+Dataset is a chunked dataset
+Retrieve the dataset's chunk indexing type
+Dataset's chunk indexing type is already version 1 B-tree: no further action
+Close the dataset
+Close the dataset creation property list
+Going to process dataset:/GROUP/DSET_NDATA_FA...
+Open the dataset
+Retrieve the dataset's layout
+Dataset is a chunked dataset
+Retrieve the dataset's chunk indexing type
+Dataset's chunk indexing type is already version 1 B-tree: no further action
 Close the dataset
 Close the dataset creation property list
-Going to process dataset:/GROUP/DSET_BT1...
+Going to process dataset:/GROUP/DSET_NDATA_NONE...
 Open the dataset
 Retrieve the dataset's layout
-Verify the dataset is a chunked dataset
+Dataset is a chunked dataset
 Retrieve the dataset's chunk indexing type
-Chunk indexing type is already version 1 B-tree: no further action
+Dataset's chunk indexing type is already version 1 B-tree: no further action
 Close the dataset
 Close the dataset creation property list
-Processing the file's superblock version...
+Processing the file's superblock...
 Close the file
diff --git a/tools/h5format_convert/testfiles/h5fc_v_bt1.ddl b/tools/h5format_convert/testfiles/h5fc_v_bt1.ddl
index c96b647..c501eb0 100644
--- a/tools/h5format_convert/testfiles/h5fc_v_bt1.ddl
+++ b/tools/h5format_convert/testfiles/h5fc_v_bt1.ddl
@@ -1,12 +1,12 @@
 Process command line options
 Open the file tmp.h5
-Going to process dataset: /GROUP/DSET_BT1...
+Going to process dataset: /GROUP/DSET_BT2...
 Open the dataset
 Retrieve the dataset's layout
-Verify the dataset is a chunked dataset
+Dataset is a chunked dataset
 Retrieve the dataset's chunk indexing type
-Chunk indexing type is already version 1 B-tree: no further action
+Dataset's chunk indexing type is already version 1 B-tree: no further action
 Close the dataset
 Close the dataset creation property list
-Processing the file's superblock version...
+Processing the file's superblock...
 Close the file
diff --git a/tools/h5format_convert/testfiles/h5fc_v_n_1d.ddl b/tools/h5format_convert/testfiles/h5fc_v_n_1d.ddl
index a7a622a..ff5da4a 100644
--- a/tools/h5format_convert/testfiles/h5fc_v_n_1d.ddl
+++ b/tools/h5format_convert/testfiles/h5fc_v_n_1d.ddl
@@ -4,11 +4,11 @@ Open the file tmp.h5
 Going to process dataset: /DSET_EA...
 Open the dataset
 Retrieve the dataset's layout
-Verify the dataset is a chunked dataset
+Dataset is a chunked dataset
 Retrieve the dataset's chunk indexing type
-Verify the dataset's chunk indexing type is not version 1 B-tree
+Dataset's chunk indexing type is not version 1 B-tree
 Not converting the dataset
 Close the dataset
 Close the dataset creation property list
-Not processing the file's superblock version...
+Not processing the file's superblock...
 Close the file
diff --git a/tools/h5format_convert/testfiles/h5fc_v_n_all.ddl b/tools/h5format_convert/testfiles/h5fc_v_n_all.ddl
index 3e92568..d2ffbbf 100644
--- a/tools/h5format_convert/testfiles/h5fc_v_n_all.ddl
+++ b/tools/h5format_convert/testfiles/h5fc_v_n_all.ddl
@@ -2,47 +2,55 @@ Process command line options
 It is noop...
 Open the file tmp.h5
 Processing all datasets in the file...
+Going to process dataset:/DSET_CONTIGUOUS...
+Open the dataset
+Retrieve the dataset's layout
+Dataset is a contiguous dataset: downgrade layout version as needed
+Not converting the dataset
+Close the dataset
+Close the dataset creation property list
 Going to process dataset:/DSET_NDATA_BT2...
 Open the dataset
 Retrieve the dataset's layout
-Verify the dataset is a chunked dataset
+Dataset is a chunked dataset
 Retrieve the dataset's chunk indexing type
-Verify the dataset's chunk indexing type is not version 1 B-tree
+Dataset's chunk indexing type is not version 1 B-tree
 Not converting the dataset
 Close the dataset
 Close the dataset creation property list
 Going to process dataset:/DSET_NDATA_EA...
 Open the dataset
 Retrieve the dataset's layout
-Verify the dataset is a chunked dataset
+Dataset is a chunked dataset
 Retrieve the dataset's chunk indexing type
-Verify the dataset's chunk indexing type is not version 1 B-tree
+Dataset's chunk indexing type is not version 1 B-tree
 Not converting the dataset
 Close the dataset
 Close the dataset creation property list
 Going to process dataset:/GROUP/DSET_BT2...
 Open the dataset
 Retrieve the dataset's layout
-Verify the dataset is a chunked dataset
+Dataset is a chunked dataset
 Retrieve the dataset's chunk indexing type
-Verify the dataset's chunk indexing type is not version 1 B-tree
+Dataset's chunk indexing type is not version 1 B-tree
 Not converting the dataset
 Close the dataset
 Close the dataset creation property list
-Going to process dataset:/GROUP/DSET_EA...
+Going to process dataset:/GROUP/DSET_COMPACT...
 Open the dataset
 Retrieve the dataset's layout
-Verify the dataset is a chunked dataset
-Retrieve the dataset's chunk indexing type
-Verify the dataset's chunk indexing type is not version 1 B-tree
+Dataset is a contiguous dataset: downgrade layout version as needed
 Not converting the dataset
 Close the dataset
 Close the dataset creation property list
-Going to process dataset:/GROUP/DSET_NON_CHUNKED...
+Going to process dataset:/GROUP/DSET_EA...
 Open the dataset
 Retrieve the dataset's layout
-Dataset is not chunked: no further action
+Dataset is a chunked dataset
+Retrieve the dataset's chunk indexing type
+Dataset's chunk indexing type is not version 1 B-tree
+Not converting the dataset
 Close the dataset
 Close the dataset creation property list
-Not processing the file's superblock version...
+Not processing the file's superblock...
 Close the file
diff --git a/tools/h5format_convert/testfiles/h5fc_v_ndata_bt1.ddl b/tools/h5format_convert/testfiles/h5fc_v_ndata_bt1.ddl
index bdf3380..ba794a7 100644
--- a/tools/h5format_convert/testfiles/h5fc_v_ndata_bt1.ddl
+++ b/tools/h5format_convert/testfiles/h5fc_v_ndata_bt1.ddl
@@ -1,13 +1,13 @@
 Process command line options
 It is noop...
 Open the file tmp.h5
-Going to process dataset: /DSET_NDATA_BT1...
+Going to process dataset: /DSET_NDATA_BT2...
 Open the dataset
 Retrieve the dataset's layout
-Verify the dataset is a chunked dataset
+Dataset is a chunked dataset
 Retrieve the dataset's chunk indexing type
-Chunk indexing type is already version 1 B-tree: no further action
+Dataset's chunk indexing type is already version 1 B-tree: no further action
 Close the dataset
 Close the dataset creation property list
-Not processing the file's superblock version...
+Not processing the file's superblock...
 Close the file
diff --git a/tools/h5format_convert/testfiles/h5fc_v_non_chunked.ddl b/tools/h5format_convert/testfiles/h5fc_v_non_chunked.ddl
index 4caafe9..aba0740 100644
--- a/tools/h5format_convert/testfiles/h5fc_v_non_chunked.ddl
+++ b/tools/h5format_convert/testfiles/h5fc_v_non_chunked.ddl
@@ -1,10 +1,12 @@
 Process command line options
 Open the file tmp.h5
-Going to process dataset: /DSET_NON_CHUNKED...
+Going to process dataset: /DSET_CONTIGUOUS...
 Open the dataset
 Retrieve the dataset's layout
-Dataset is not chunked: no further action
+Dataset is a contiguous dataset: downgrade layout version as needed
+Converting the dataset...
+Done
 Close the dataset
 Close the dataset creation property list
-Processing the file's superblock version...
+Processing the file's superblock...
 Close the file
diff --git a/tools/h5format_convert/testfiles/old_h5fc_ext1_f.ddl b/tools/h5format_convert/testfiles/old_h5fc_ext1_f.ddl
new file mode 100644
index 0000000..fb5192d
--- /dev/null
+++ b/tools/h5format_convert/testfiles/old_h5fc_ext1_f.ddl
@@ -0,0 +1,58 @@
+HDF5 "./testfiles/tmp.h5" {
+SUPER_BLOCK {
+   SUPERBLOCK_VERSION 2
+   FREELIST_VERSION 0
+   SYMBOLTABLE_VERSION 0
+   OBJECTHEADER_VERSION 0
+   OFFSET_SIZE 8
+   LENGTH_SIZE 8
+   BTREE_RANK 16
+   BTREE_LEAF 4
+   ISTORE_K 32
+   FILE_SPACE_STRATEGY H5F_FILE_SPACE_ALL
+   FREE_SPACE_THRESHOLD 1
+   USER_BLOCK {
+      USERBLOCK_SIZE 0
+   }
+}
+GROUP "/" {
+   DATASET "DSET_CONTIGUOUS" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 10 ) / ( 10 ) }
+   }
+   DATASET "DSET_EA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_FA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+   }
+   DATASET "DSET_NDATA_BT2" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_NONE" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+   }
+   GROUP "GROUP" {
+      DATASET "DSET_BT2" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_EA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_FA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+      }
+      DATASET "DSET_NDATA_NONE" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+      }
+   }
+}
+}
diff --git a/tools/h5format_convert/testfiles/old_h5fc_ext1_f.h5 b/tools/h5format_convert/testfiles/old_h5fc_ext1_f.h5
new file mode 100644
index 0000000..3cbc7f4
--- /dev/null
+++ b/tools/h5format_convert/testfiles/old_h5fc_ext1_f.h5
diff --git a/tools/h5format_convert/testfiles/old_h5fc_ext1_i.ddl b/tools/h5format_convert/testfiles/old_h5fc_ext1_i.ddl
new file mode 100644
index 0000000..c906082
--- /dev/null
+++ b/tools/h5format_convert/testfiles/old_h5fc_ext1_i.ddl
@@ -0,0 +1,58 @@
+HDF5 "./testfiles/tmp.h5" {
+SUPER_BLOCK {
+   SUPERBLOCK_VERSION 1
+   FREELIST_VERSION 0
+   SYMBOLTABLE_VERSION 0
+   OBJECTHEADER_VERSION 0
+   OFFSET_SIZE 8
+   LENGTH_SIZE 8
+   BTREE_RANK 16
+   BTREE_LEAF 4
+   ISTORE_K 64
+   FILE_SPACE_STRATEGY H5F_FILE_SPACE_ALL
+   FREE_SPACE_THRESHOLD 1
+   USER_BLOCK {
+      USERBLOCK_SIZE 0
+   }
+}
+GROUP "/" {
+   DATASET "DSET_CONTIGUOUS" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 10 ) / ( 10 ) }
+   }
+   DATASET "DSET_EA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_FA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+   }
+   DATASET "DSET_NDATA_BT2" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_NONE" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+   }
+   GROUP "GROUP" {
+      DATASET "DSET_BT2" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_EA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_FA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+      }
+      DATASET "DSET_NDATA_NONE" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+      }
+   }
+}
+}
diff --git a/tools/h5format_convert/testfiles/old_h5fc_ext1_i.h5 b/tools/h5format_convert/testfiles/old_h5fc_ext1_i.h5
new file mode 100644
index 0000000..a2c9187
--- /dev/null
+++ b/tools/h5format_convert/testfiles/old_h5fc_ext1_i.h5
diff --git a/tools/h5format_convert/testfiles/old_h5fc_ext1_s.ddl b/tools/h5format_convert/testfiles/old_h5fc_ext1_s.ddl
new file mode 100644
index 0000000..fb5192d
--- /dev/null
+++ b/tools/h5format_convert/testfiles/old_h5fc_ext1_s.ddl
@@ -0,0 +1,58 @@
+HDF5 "./testfiles/tmp.h5" {
+SUPER_BLOCK {
+   SUPERBLOCK_VERSION 2
+   FREELIST_VERSION 0
+   SYMBOLTABLE_VERSION 0
+   OBJECTHEADER_VERSION 0
+   OFFSET_SIZE 8
+   LENGTH_SIZE 8
+   BTREE_RANK 16
+   BTREE_LEAF 4
+   ISTORE_K 32
+   FILE_SPACE_STRATEGY H5F_FILE_SPACE_ALL
+   FREE_SPACE_THRESHOLD 1
+   USER_BLOCK {
+      USERBLOCK_SIZE 0
+   }
+}
+GROUP "/" {
+   DATASET "DSET_CONTIGUOUS" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 10 ) / ( 10 ) }
+   }
+   DATASET "DSET_EA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_FA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+   }
+   DATASET "DSET_NDATA_BT2" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_NONE" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+   }
+   GROUP "GROUP" {
+      DATASET "DSET_BT2" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_EA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_FA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+      }
+      DATASET "DSET_NDATA_NONE" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+      }
+   }
+}
+}
diff --git a/tools/h5format_convert/testfiles/old_h5fc_ext1_s.h5 b/tools/h5format_convert/testfiles/old_h5fc_ext1_s.h5
new file mode 100644
index 0000000..fdf4f33
--- /dev/null
+++ b/tools/h5format_convert/testfiles/old_h5fc_ext1_s.h5
diff --git a/tools/h5format_convert/testfiles/old_h5fc_ext2_if.ddl b/tools/h5format_convert/testfiles/old_h5fc_ext2_if.ddl
new file mode 100644
index 0000000..2fff4ac
--- /dev/null
+++ b/tools/h5format_convert/testfiles/old_h5fc_ext2_if.ddl
@@ -0,0 +1,58 @@
+HDF5 "./testfiles/tmp.h5" {
+SUPER_BLOCK {
+   SUPERBLOCK_VERSION 2
+   FREELIST_VERSION 0
+   SYMBOLTABLE_VERSION 0
+   OBJECTHEADER_VERSION 0
+   OFFSET_SIZE 8
+   LENGTH_SIZE 8
+   BTREE_RANK 16
+   BTREE_LEAF 4
+   ISTORE_K 64
+   FILE_SPACE_STRATEGY H5F_FILE_SPACE_ALL
+   FREE_SPACE_THRESHOLD 1
+   USER_BLOCK {
+      USERBLOCK_SIZE 0
+   }
+}
+GROUP "/" {
+   DATASET "DSET_CONTIGUOUS" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 10 ) / ( 10 ) }
+   }
+   DATASET "DSET_EA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_FA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+   }
+   DATASET "DSET_NDATA_BT2" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_NONE" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+   }
+   GROUP "GROUP" {
+      DATASET "DSET_BT2" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_EA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_FA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+      }
+      DATASET "DSET_NDATA_NONE" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+      }
+   }
+}
+}
diff --git a/tools/h5format_convert/testfiles/old_h5fc_ext2_if.h5 b/tools/h5format_convert/testfiles/old_h5fc_ext2_if.h5
new file mode 100644
index 0000000..6bf0a2f
--- /dev/null
+++ b/tools/h5format_convert/testfiles/old_h5fc_ext2_if.h5
diff --git a/tools/h5format_convert/testfiles/old_h5fc_ext2_is.ddl b/tools/h5format_convert/testfiles/old_h5fc_ext2_is.ddl
new file mode 100644
index 0000000..2fff4ac
--- /dev/null
+++ b/tools/h5format_convert/testfiles/old_h5fc_ext2_is.ddl
@@ -0,0 +1,58 @@
+HDF5 "./testfiles/tmp.h5" {
+SUPER_BLOCK {
+   SUPERBLOCK_VERSION 2
+   FREELIST_VERSION 0
+   SYMBOLTABLE_VERSION 0
+   OBJECTHEADER_VERSION 0
+   OFFSET_SIZE 8
+   LENGTH_SIZE 8
+   BTREE_RANK 16
+   BTREE_LEAF 4
+   ISTORE_K 64
+   FILE_SPACE_STRATEGY H5F_FILE_SPACE_ALL
+   FREE_SPACE_THRESHOLD 1
+   USER_BLOCK {
+      USERBLOCK_SIZE 0
+   }
+}
+GROUP "/" {
+   DATASET "DSET_CONTIGUOUS" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 10 ) / ( 10 ) }
+   }
+   DATASET "DSET_EA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_FA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+   }
+   DATASET "DSET_NDATA_BT2" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_NONE" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+   }
+   GROUP "GROUP" {
+      DATASET "DSET_BT2" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_EA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_FA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+      }
+      DATASET "DSET_NDATA_NONE" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+      }
+   }
+}
+}
diff --git a/tools/h5format_convert/testfiles/old_h5fc_ext2_is.h5 b/tools/h5format_convert/testfiles/old_h5fc_ext2_is.h5
new file mode 100644
index 0000000..c0c7ecc
--- /dev/null
+++ b/tools/h5format_convert/testfiles/old_h5fc_ext2_is.h5
diff --git a/tools/h5format_convert/testfiles/old_h5fc_ext2_sf.ddl b/tools/h5format_convert/testfiles/old_h5fc_ext2_sf.ddl
new file mode 100644
index 0000000..fb5192d
--- /dev/null
+++ b/tools/h5format_convert/testfiles/old_h5fc_ext2_sf.ddl
@@ -0,0 +1,58 @@
+HDF5 "./testfiles/tmp.h5" {
+SUPER_BLOCK {
+   SUPERBLOCK_VERSION 2
+   FREELIST_VERSION 0
+   SYMBOLTABLE_VERSION 0
+   OBJECTHEADER_VERSION 0
+   OFFSET_SIZE 8
+   LENGTH_SIZE 8
+   BTREE_RANK 16
+   BTREE_LEAF 4
+   ISTORE_K 32
+   FILE_SPACE_STRATEGY H5F_FILE_SPACE_ALL
+   FREE_SPACE_THRESHOLD 1
+   USER_BLOCK {
+      USERBLOCK_SIZE 0
+   }
+}
+GROUP "/" {
+   DATASET "DSET_CONTIGUOUS" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 10 ) / ( 10 ) }
+   }
+   DATASET "DSET_EA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_FA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+   }
+   DATASET "DSET_NDATA_BT2" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_NONE" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+   }
+   GROUP "GROUP" {
+      DATASET "DSET_BT2" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_EA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_FA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+      }
+      DATASET "DSET_NDATA_NONE" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+      }
+   }
+}
+}
diff --git a/tools/h5format_convert/testfiles/old_h5fc_ext2_sf.h5 b/tools/h5format_convert/testfiles/old_h5fc_ext2_sf.h5
new file mode 100644
index 0000000..055cabf
--- /dev/null
+++ b/tools/h5format_convert/testfiles/old_h5fc_ext2_sf.h5
diff --git a/tools/h5format_convert/testfiles/old_h5fc_ext3_isf.ddl b/tools/h5format_convert/testfiles/old_h5fc_ext3_isf.ddl
new file mode 100644
index 0000000..2fff4ac
--- /dev/null
+++ b/tools/h5format_convert/testfiles/old_h5fc_ext3_isf.ddl
@@ -0,0 +1,58 @@
+HDF5 "./testfiles/tmp.h5" {
+SUPER_BLOCK {
+   SUPERBLOCK_VERSION 2
+   FREELIST_VERSION 0
+   SYMBOLTABLE_VERSION 0
+   OBJECTHEADER_VERSION 0
+   OFFSET_SIZE 8
+   LENGTH_SIZE 8
+   BTREE_RANK 16
+   BTREE_LEAF 4
+   ISTORE_K 64
+   FILE_SPACE_STRATEGY H5F_FILE_SPACE_ALL
+   FREE_SPACE_THRESHOLD 1
+   USER_BLOCK {
+      USERBLOCK_SIZE 0
+   }
+}
+GROUP "/" {
+   DATASET "DSET_CONTIGUOUS" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 10 ) / ( 10 ) }
+   }
+   DATASET "DSET_EA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_FA" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+   }
+   DATASET "DSET_NDATA_BT2" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+   }
+   DATASET "DSET_NONE" {
+      DATATYPE  H5T_STD_I32LE
+      DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+   }
+   GROUP "GROUP" {
+      DATASET "DSET_BT2" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( H5S_UNLIMITED, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_EA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 10, H5S_UNLIMITED ) }
+      }
+      DATASET "DSET_NDATA_FA" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 20, 10 ) }
+      }
+      DATASET "DSET_NDATA_NONE" {
+         DATATYPE  H5T_STD_I32LE
+         DATASPACE  SIMPLE { ( 4, 6 ) / ( 4, 6 ) }
+      }
+   }
+}
+}
diff --git a/tools/h5format_convert/testfiles/old_h5fc_ext3_isf.h5 b/tools/h5format_convert/testfiles/old_h5fc_ext3_isf.h5
new file mode 100644
index 0000000..f4caaf4
--- /dev/null
+++ b/tools/h5format_convert/testfiles/old_h5fc_ext3_isf.h5
diff --git a/tools/h5format_convert/testfiles/old_h5fc_ext_none.h5 b/tools/h5format_convert/testfiles/old_h5fc_ext_none.h5
new file mode 100644
index 0000000..d0bf344
--- /dev/null
+++ b/tools/h5format_convert/testfiles/old_h5fc_ext_none.h5
diff --git a/tools/h5format_convert/testh5fc.sh.in b/tools/h5format_convert/testh5fc.sh.in
index dc5aa48..f712434 100644
--- a/tools/h5format_convert/testh5fc.sh.in
+++ b/tools/h5format_convert/testh5fc.sh.in
@@ -41,6 +41,8 @@ RM='rm -rf'
 CMP='cmp -s'
 DIFF='diff -c'
 CP='cp'
+H5DUMP=../h5dump/h5dump         # The h5dump tool name
+H5DUMP_BIN=`pwd`/$H5DUMP        # The path of the h5dump tool binary
 DIRNAME='dirname'
 LS='ls'
 AWK='awk'
@@ -79,10 +81,24 @@ TMPFILE=tmp.h5
 #       Comment '#' without space can be used.
 # --------------------------------------------------------------------
 LIST_HDF5_TEST_FILES="
-$SRC_H5FORMCONV_TESTFILES/h5fc_v1.h5
-$SRC_H5FORMCONV_TESTFILES/h5fc_latest_v3.h5
 $SRC_H5FORMCONV_TESTFILES/h5fc_non_v3.h5
 $SRC_H5FORMCONV_TESTFILES/h5fc_edge_v3.h5
+$SRC_H5FORMCONV_TESTFILES/h5fc_ext_none.h5
+$SRC_H5FORMCONV_TESTFILES/old_h5fc_ext_none.h5
+$SRC_H5FORMCONV_TESTFILES/h5fc_ext1_i.h5
+$SRC_H5FORMCONV_TESTFILES/h5fc_ext1_s.h5
+$SRC_H5FORMCONV_TESTFILES/h5fc_ext1_f.h5
+$SRC_H5FORMCONV_TESTFILES/h5fc_ext2_if.h5
+$SRC_H5FORMCONV_TESTFILES/h5fc_ext2_is.h5
+$SRC_H5FORMCONV_TESTFILES/h5fc_ext2_sf.h5
+$SRC_H5FORMCONV_TESTFILES/h5fc_ext3_isf.h5
+$SRC_H5FORMCONV_TESTFILES/old_h5fc_ext1_i.h5
+$SRC_H5FORMCONV_TESTFILES/old_h5fc_ext1_s.h5
+$SRC_H5FORMCONV_TESTFILES/old_h5fc_ext1_f.h5
+$SRC_H5FORMCONV_TESTFILES/old_h5fc_ext2_if.h5
+$SRC_H5FORMCONV_TESTFILES/old_h5fc_ext2_is.h5
+$SRC_H5FORMCONV_TESTFILES/old_h5fc_ext2_sf.h5
+$SRC_H5FORMCONV_TESTFILES/old_h5fc_ext3_isf.h5
 "
 
 LIST_OTHER_TEST_FILES="
@@ -98,6 +114,20 @@ $SRC_H5FORMCONV_TESTFILES/h5fc_v_ndata_bt1.ddl
 $SRC_H5FORMCONV_TESTFILES/h5fc_v_all.ddl
 $SRC_H5FORMCONV_TESTFILES/h5fc_v_n_1d.ddl
 $SRC_H5FORMCONV_TESTFILES/h5fc_v_n_all.ddl
+$SRC_H5FORMCONV_TESTFILES/h5fc_ext1_i.ddl
+$SRC_H5FORMCONV_TESTFILES/h5fc_ext1_s.ddl
+$SRC_H5FORMCONV_TESTFILES/h5fc_ext1_f.ddl
+$SRC_H5FORMCONV_TESTFILES/h5fc_ext2_if.ddl
+$SRC_H5FORMCONV_TESTFILES/h5fc_ext2_is.ddl
+$SRC_H5FORMCONV_TESTFILES/h5fc_ext2_sf.ddl
+$SRC_H5FORMCONV_TESTFILES/h5fc_ext3_isf.ddl
+$SRC_H5FORMCONV_TESTFILES/old_h5fc_ext1_i.ddl
+$SRC_H5FORMCONV_TESTFILES/old_h5fc_ext1_s.ddl
+$SRC_H5FORMCONV_TESTFILES/old_h5fc_ext1_f.ddl
+$SRC_H5FORMCONV_TESTFILES/old_h5fc_ext2_if.ddl
+$SRC_H5FORMCONV_TESTFILES/old_h5fc_ext2_is.ddl
+$SRC_H5FORMCONV_TESTFILES/old_h5fc_ext2_sf.ddl
+$SRC_H5FORMCONV_TESTFILES/old_h5fc_ext3_isf.ddl
 "
 
 #
@@ -199,14 +229,7 @@ TOOLTEST_OUT() {
     cat $actual_err >> $actual
 
     # Compare output
-    if $CMP $expect $actual; then
-	echo " PASSED"
-    else
-	echo "*FAILED*"
-	echo "    Expected result (*.ddl) differs from actual result (*.out)"
-	nerrors="`expr $nerrors + 1`"
-	test yes = "$verbose" && $DIFF $expect $actual |sed 's/^/    /'
-    fi
+    COMPARE_OUT $expect $actual
 
     # Clean up output file
     if test -z "$HDF5_NOCLEANUP"; then
@@ -243,8 +266,8 @@ CHECKING() {
    echo "Verifying $* $SPACES" | cut -c1-80 | tr -d '\012'
 }
 
-# $1 dataset name
 # Assume $TESTDIR/$TMPFILE is the converted test file
+# $1 dataset name
 IDX_CHECK() {
     CHECKING $1
     $RUNSERIAL $CHK_IDX_BIN $TESTDIR/$TMPFILE $1
@@ -258,6 +281,39 @@ IDX_CHECK() {
     fi
 }
 
+# $1 is the expected output
+# $2 is the output from testing
+COMPARE_OUT() {
+    if $CMP $1 $2; then
+        echo " PASSED"
+    else
+        echo "*FAILED*"
+        echo "    Expected result (*.ddl) differs from actual result (*.out)"
+        nerrors="`expr $nerrors + 1`"
+        test yes = "$verbose" && $DIFF $expect $actual |sed 's/^/    /'
+    fi
+}
+
+# Assume $TESTDIR/$TMPFILE is the converted test file
+# $1 is the test file for verifying h5dump output
+# $2 is the expected output from h5dump
+H5DUMP_CHECK() {
+    CHECKING h5dump output for $1
+    expect="$TESTDIR/$2"
+    actual="$TESTDIR/`basename $2 .ddl`.out"
+    actual_err="$TESTDIR/`basename $2 .ddl`.err"
+    $RUNSERIAL $H5DUMP_BIN -BH $TESTDIR/$TMPFILE > $actual 2>$actual_err
+    cat $actual_err >> $actual
+
+    # Compare output
+    COMPARE_OUT $expect $actual
+
+    # Clean up output file
+    if test -z "$HDF5_NOCLEANUP"; then
+	$RM $actual $actual_err
+    fi
+}
+
 # Print a "SKIP" message
 SKIP() {
     TESTING $STAT $@
@@ -284,31 +340,31 @@ TOOLTEST_OUT h5fc_nooption.ddl ''
 TOOLTEST_OUT h5fc_nonexistfile.ddl nonexist.h5
 #
 #
-# h5format_convert -d h5fc_v1.h5 (just -d option, file exists)
-# h5format_convert --dname h5fc_v1.h5 (just --dname option, file exists)
+# h5format_convert -d old_h5fc_ext_none.h5 (just -d option, file exists)
+# h5format_convert --dname old_h5fc_ext_none.h5 (just --dname option, file exists)
 # h5format_convert --dname (just --dname option)
-# h5format_convert --dname=nonexist h5fc_v1.h5 (dataset does not exist, file exists)
-TOOLTEST_OUT h5fc_d_file.ddl h5fc_v1.h5 -d
-TOOLTEST_OUT h5fc_d_file.ddl h5fc_v1.h5 --dname
+# h5format_convert --dname=nonexist old_h5fc_ext_none.h5 (dataset does not exist, file exists)
+TOOLTEST_OUT h5fc_d_file.ddl old_h5fc_ext_none.h5 -d
+TOOLTEST_OUT h5fc_d_file.ddl old_h5fc_ext_none.h5 --dname
 TOOLTEST_OUT h5fc_dname.ddl '' --dname
-TOOLTEST_OUT h5fc_nonexistdset_file.ddl h5fc_v1.h5 --dname=nonexist
+TOOLTEST_OUT h5fc_nonexistdset_file.ddl old_h5fc_ext_none.h5 --dname=nonexist
 #
 #
 #
-# h5format_convert -d /DSET_NON_CHUNKED -v h5fc_v1.h5 (verbose, non-chunked dataset)
-# h5format_convert -d /GROUP/DSET_BT1 --verbose h5fc_v1.h5 (verbose, bt1 dataset)
-# h5format_convert -d /DSET_NDATA_BT1 -v -n h5fc_v1.h5 (verbose, noop, bt1+nodata dataset)
-# h5format_convert -v h5fc_v1.h5 (verbose, all datasets)
-TOOLTEST_OUT h5fc_v_non_chunked.ddl h5fc_v1.h5 -d /DSET_NON_CHUNKED -v
-TOOLTEST_OUT h5fc_v_bt1.ddl h5fc_v1.h5 -d /GROUP/DSET_BT1 --verbose
-TOOLTEST_OUT h5fc_v_ndata_bt1.ddl h5fc_v1.h5 -d /DSET_NDATA_BT1 -v -n
-TOOLTEST_OUT h5fc_v_all.ddl h5fc_v1.h5 -v
+# h5format_convert -d /DSET_CONTIGUOUS -v old_h5fc_ext_none.h5 (verbose, contiguous dataset)
+# h5format_convert -d /GROUP/DSET_BT2 --verbose old_h5fc_ext_none.h5 (verbose, bt1 dataset)
+# h5format_convert -d /DSET_NDATA_BT2 -v -n old_h5fc_ext_none.h5 (verbose, noop, bt1+nodata dataset)
+# h5format_convert -v old_h5fc_ext_none.h5 (verbose, all datasets)
+TOOLTEST_OUT h5fc_v_non_chunked.ddl old_h5fc_ext_none.h5 -d /DSET_CONTIGUOUS -v
+TOOLTEST_OUT h5fc_v_bt1.ddl old_h5fc_ext_none.h5 -d /GROUP/DSET_BT2 --verbose
+TOOLTEST_OUT h5fc_v_ndata_bt1.ddl old_h5fc_ext_none.h5 -d /DSET_NDATA_BT2 -v -n
+TOOLTEST_OUT h5fc_v_all.ddl old_h5fc_ext_none.h5 -v
 #
 #
 #
-# h5format_convert -d /DSET_EA -v -n h5fc_latest_v3.h5 (verbose, noop, one ea dataset)
+# h5format_convert -d /DSET_EA -v -n h5fc_ext_none.h5 (verbose, noop, one ea dataset)
 # h5format_convert -v -n h5fc_non_v3.h5 (verbose, noop, all datasets)
-TOOLTEST_OUT h5fc_v_n_1d.ddl h5fc_latest_v3.h5 -d /DSET_EA -v -n
+TOOLTEST_OUT h5fc_v_n_1d.ddl h5fc_ext_none.h5 -d /DSET_EA -v -n
 TOOLTEST_OUT h5fc_v_n_all.ddl h5fc_non_v3.h5 -v -n
 #
 #
@@ -316,45 +372,45 @@ TOOLTEST_OUT h5fc_v_n_all.ddl h5fc_non_v3.h5 -v -n
 # No output from tests
 # 1) Use the tool to convert the dataset
 # 2) Verify the chunk indexing type is correct
-# h5format_convert -d /DSET_EA h5fc_latest_v3.h5
-# h5format_convert -d /GROUP/DSET_NDATA_EA h5fc_latest_v3.h5
-# h5format_convert -d /GROUP/DSET_BT2 h5fc_latest_v3.h5
-# h5format_convert -d /DSET_NDATA_BT2 h5fc_latest_v3.h5
-# h5format_convert -d /DSET_FA h5fc_latest_v3.h5
-# h5format_convert -d /GROUP/DSET_FA h5fc_latest_v3.h5
-# h5format_convert -d /DSET_NONE h5fc_latest_v3.h5
-# h5format_convert -d /GROUP/DSET_NONE h5fc_latest_v3.h5
-TOOLTEST h5fc_latest_v3.h5 -d /DSET_EA
+# h5format_convert -d /DSET_EA h5fc_ext_none.h5
+# h5format_convert -d /GROUP/DSET_NDATA_EA h5fc_ext_none.h5
+# h5format_convert -d /GROUP/DSET_BT2 h5fc_ext_none.h5
+# h5format_convert -d /DSET_NDATA_BT2 h5fc_ext_none.h5
+# h5format_convert -d /DSET_FA h5fc_ext_none.h5
+# h5format_convert -d /GROUP/DSET_FA h5fc_ext_none.h5
+# h5format_convert -d /DSET_NONE h5fc_ext_none.h5
+# h5format_convert -d /GROUP/DSET_NDATA_NONE h5fc_ext_none.h5
+TOOLTEST h5fc_ext_none.h5 -d /DSET_EA
 IDX_CHECK /DSET_EA
 #
-TOOLTEST h5fc_latest_v3.h5 -d /GROUP/DSET_NDATA_EA
+TOOLTEST h5fc_ext_none.h5 -d /GROUP/DSET_NDATA_EA
 IDX_CHECK /GROUP/DSET_NDATA_EA
 #
-TOOLTEST h5fc_latest_v3.h5 -d /GROUP/DSET_BT2
+TOOLTEST h5fc_ext_none.h5 -d /GROUP/DSET_BT2
 IDX_CHECK /GROUP/DSET_BT2
 #
-TOOLTEST h5fc_latest_v3.h5 -d /DSET_NDATA_BT2
+TOOLTEST h5fc_ext_none.h5 -d /DSET_NDATA_BT2
 IDX_CHECK /DSET_NDATA_BT2
 #
-TOOLTEST h5fc_latest_v3.h5 -d /DSET_FA
+TOOLTEST h5fc_ext_none.h5 -d /DSET_FA
 IDX_CHECK /DSET_FA
 #
-TOOLTEST h5fc_latest_v3.h5 -d /GROUP/DSET_NDATA_FA
+TOOLTEST h5fc_ext_none.h5 -d /GROUP/DSET_NDATA_FA
 IDX_CHECK /GROUP/DSET_NDATA_FA
 #
-TOOLTEST h5fc_latest_v3.h5 -d /DSET_NONE
+TOOLTEST h5fc_ext_none.h5 -d /DSET_NONE
 IDX_CHECK /DSET_NONE
 #
-TOOLTEST h5fc_latest_v3.h5 -d /GROUP/DSET_NDATA_NONE
+TOOLTEST h5fc_ext_none.h5 -d /GROUP/DSET_NDATA_NONE
 IDX_CHECK /GROUP/DSET_NDATA_NONE
 #
 #
 #
 # No output from tests: just check exit code
-# h5format_convert -d /DSET_NDATA_BT1 h5fc_v1.h5 (v1-btree dataset)
-# h5format_convert -d /GROUP/DSET_NON_CHUNKED h5fc_non_v3.h5 (non-chunked dataset)
-TOOLTEST h5fc_v1.h5 -d /DSET_NDATA_BT1
-TOOLTEST h5fc_non_v3.h5 -d /GROUP/DSET_NON_CHUNKED
+# h5format_convert -d /DSET_NDATA_BT2 old_h5fc_ext_none.h5 (v1-btree dataset)
+# h5format_convert -d /DSET_CONTIGUOUS h5fc_non_v3.h5 (non-chunked dataset)
+TOOLTEST old_h5fc_ext_none.h5 -d /DSET_NDATA_BT2
+TOOLTEST h5fc_non_v3.h5 -d /DSET_CONTIGUOUS
 #
 #
 #
@@ -386,6 +442,44 @@ TOOLTEST h5fc_edge_v3.h5
 IDX_CHECK /DSET_EDGE
 #
 #
+
+# The following test files have messages in the superblock extension.
+# Verify h5dump output for correctness after conversion
+TOOLTEST h5fc_ext1_i.h5
+H5DUMP_CHECK h5fc_ext1_i.h5 h5fc_ext1_i.ddl
+TOOLTEST h5fc_ext1_s.h5
+H5DUMP_CHECK h5fc_ext1_s.h5 h5fc_ext1_s.ddl
+TOOLTEST h5fc_ext1_f.h5
+H5DUMP_CHECK h5fc_ext1_f.h5 h5fc_ext1_f.ddl
+#
+TOOLTEST h5fc_ext2_if.h5
+H5DUMP_CHECK h5fc_ext2_if.h5 h5fc_ext2_if.ddl
+TOOLTEST h5fc_ext2_is.h5
+H5DUMP_CHECK h5fc_ext2_is.h5 h5fc_ext2_is.ddl
+TOOLTEST h5fc_ext2_sf.h5
+H5DUMP_CHECK h5fc_ext2_sf.h5 h5fc_ext2_sf.ddl
+#
+TOOLTEST h5fc_ext3_isf.h5
+H5DUMP_CHECK h5fc_ext3_isf.h5 h5fc_ext3_isf.ddl
+#
+#
+#
+TOOLTEST old_h5fc_ext1_i.h5
+H5DUMP_CHECK old_h5fc_ext1_i.h5 old_h5fc_ext1_i.ddl
+TOOLTEST old_h5fc_ext1_s.h5
+H5DUMP_CHECK old_h5fc_ext1_s.h5 old_h5fc_ext1_s.ddl
+TOOLTEST old_h5fc_ext1_f.h5
+H5DUMP_CHECK old_h5fc_ext1_f.h5 old_h5fc_ext1_f.ddl
+#
+TOOLTEST old_h5fc_ext2_if.h5
+H5DUMP_CHECK old_h5fc_ext2_if.h5 old_h5fc_ext2_if.ddl
+TOOLTEST old_h5fc_ext2_is.h5
+H5DUMP_CHECK old_h5fc_ext2_is.h5 old_h5fc_ext2_is.ddl
+TOOLTEST old_h5fc_ext2_sf.h5
+H5DUMP_CHECK old_h5fc_ext2_sf.h5 old_h5fc_ext2_sf.ddl
+#
+TOOLTEST old_h5fc_ext3_isf.h5
+H5DUMP_CHECK old_h5fc_ext3_isf.h5 old_h5fc_ext3_isf.ddl
 #
 # Clean up temporary files/directories
 CLEAN_TESTFILES_AND_TESTDIR