Merge pull request #1671 from vchoi-hdfgroup/new_vds_feature_vfd_swmr

New vds feature vfd swmr

39 files changed, 944 insertions, 445 deletions

diff --git a/src/H5Dvirtual.c b/src/H5Dvirtual.c
index c26697c..c7d47ef 100644
--- a/src/H5Dvirtual.c
+++ b/src/H5Dvirtual.c
@@ -912,16 +912,10 @@ H5D__virtual_open_source_dset(const H5D_t *vdset, H5O_storage_virtual_ent_t *vir
         /* Get the virtual dataset's file open flags ("intent") */
         intent = H5F_INTENT(vdset->oloc.file);
 
-        /* Try opening the file */
-        /* XXX Pass the special file-access property list ID,
-         * H5P_FILE_ACCESS_ANY_VFD, so that if the file is already open in
-         * VFD SWMR mode, the library just creates a new H5F_t for the file
-         * instead of returning an error because of the discrepancy between
-         * the default file-access properties and the already-open file's
-         * VFD SWMR properties.
-         */
+        /* Remove H5P_FILE_ACCESS_ANY_VFD and restore the original code */
         src_file = H5F_prefix_open_file(vdset->oloc.file, H5F_PREFIX_VDS, vdset->shared->vds_prefix,
-                                        source_dset->file_name, intent, H5P_FILE_ACCESS_ANY_VFD);
+                                        source_dset->file_name, intent,
+                                        vdset->shared->layout.storage.u.virt.source_fapl);
 
         /* If we opened the source file here, we should close it when leaving */
         if (src_file)
diff --git a/src/H5FDprivate.h b/src/H5FDprivate.h
index fa51574..dae38b6 100644
--- a/src/H5FDprivate.h
+++ b/src/H5FDprivate.h
@@ -370,11 +370,15 @@ H5_DLL herr_t  H5FD_set_paged_aggr(H5FD_t *file, hbool_t paged);
 H5_DLL herr_t H5FD_init(void);
 
 /* Function prototypes for VFD SWMR */
-H5_DLL herr_t H5FD_vfd_swmr_get_tick_and_idx(H5FD_t *_file, hbool_t read_index, uint64_t *tick_ptr,
-                                             uint32_t *num_entries_ptr, H5FD_vfd_swmr_idx_entry_t index[]);
-H5_DLL void   H5FD_vfd_swmr_dump_status(H5FD_t *file, uint64_t page);
-H5_DLL void   H5FD_vfd_swmr_set_pb_configured(H5FD_t *_file);
-H5_DLL void   H5FD_vfd_swmr_record_elapsed_ticks(H5FD_t *_file, uint64_t elapsed);
+H5_DLL herr_t  H5FD_vfd_swmr_get_tick_and_idx(H5FD_t *_file, hbool_t read_index, uint64_t *tick_ptr,
+                                              uint32_t *num_entries_ptr, H5FD_vfd_swmr_idx_entry_t index[]);
+H5_DLL void    H5FD_vfd_swmr_dump_status(H5FD_t *file, uint64_t page);
+H5_DLL void    H5FD_vfd_swmr_set_pb_configured(H5FD_t *_file);
+H5_DLL void    H5FD_vfd_swmr_record_elapsed_ticks(H5FD_t *_file, uint64_t elapsed);
+H5_DLL void    H5FD_vfd_swmr_get_md_path_name(H5FD_t *_file, char **name);
+H5_DLL hbool_t H5FD_vfd_swmr_get_make_believe(H5FD_t *_file);
+H5_DLL void    H5FD_vfd_swmr_set_make_believe(H5FD_t *_file, hbool_t make_believe);
+H5_DLL htri_t  H5FD_vfd_swmr_assess_make_believe(H5FD_t *_file);
 H5_DLL H5FD_t *H5FD_vfd_swmr_dedup(H5FD_t *_self, H5FD_t *_other, hid_t fapl_id);
 
 /* Function prototypes for MPI based VFDs*/
diff --git a/src/H5FDpublic.h b/src/H5FDpublic.h
index a8d85c6..9411874 100644
--- a/src/H5FDpublic.h
+++ b/src/H5FDpublic.h
@@ -179,6 +179,12 @@
  * operations when appropriate.
  */
 #define H5FD_FEAT_MEMMANAGE 0x00010000
+/*
+ * Defining H5FD_FEAT_SUPPORTS_VFD_SWMR for a VFL driver means that the
+ * driver supports the SWMR feature that is implemented in a more modular
+ * fashion and simplifies maintenance.
+ */
+#define H5FD_FEAT_SUPPORTS_VFD_SWMR 0x00020000
 
 /* ctl function definitions: */
 #define H5FD_CTL_OPC_RESERVED 512 /* Opcodes below this value are reserved for library use */
diff --git a/src/H5FDvfd_swmr.c b/src/H5FDvfd_swmr.c
index fb88de3..892d084 100644
--- a/src/H5FDvfd_swmr.c
+++ b/src/H5FDvfd_swmr.c
@@ -15,9 +15,10 @@
  */
 
 #include "H5FDdrvr_module.h" /* This source code file is part of the H5FD driver module */
+#define H5F_FRIEND           /* Suppress error about including H5Fpkg            */
 
 #include "H5Eprivate.h"      /* Error handling           */
-#include "H5Fprivate.h"      /* File access              */
+#include "H5Fpkg.h"          /* Files                    */
 #include "H5FDprivate.h"     /* File drivers             */
 #include "H5FDvfd_swmr.h"    /* VFD SWMR file driver     */
 #include "H5FLprivate.h"     /* Free Lists               */
@@ -40,9 +41,9 @@ typedef struct H5FD_vfd_swmr_t {
     /* Metadata file */
     int                     md_fd;             /* File descriptor for the metadata file */
     uint32_t                md_pages_reserved; /* # of pages reserved at the head of the metadata file */
-    char                    md_file_path[H5FD_MAX_FILENAME_LEN]; /* Name of the metadate file */
-    H5FD_vfd_swmr_md_header md_header;                           /* Metadata file header */
-    H5FD_vfd_swmr_md_index  md_index;                            /* Metadata file index */
+    char                    md_file_path_name[H5FD_MAX_FILENAME_LEN + 1]; /* Name of the metadate file */
+    H5FD_vfd_swmr_md_header md_header;                                    /* Metadata file header */
+    H5FD_vfd_swmr_md_index  md_index;                                     /* Metadata file index */
 
     /* Histogram of ticks elapsed inside the API (reader only).
      * api_elapsed_ticks[elapsed] is the number of times
@@ -60,10 +61,15 @@ typedef struct H5FD_vfd_swmr_t {
      * to the lower VFD instance.
      */
     hbool_t writer;
+    /*
+     * Indicate whether we are in make_believe state or not
+     */
+    hbool_t make_believe;
 
 } H5FD_vfd_swmr_t;
 
-#define MAXADDR (((haddr_t)1 << (8 * sizeof(HDoff_t) - 1)) - 1)
+#define MAXADDR            (((haddr_t)1 << (8 * sizeof(HDoff_t) - 1)) - 1)
+#define VFD_SWMR_MD_SUFFIX ".md"
 
 /* Prototypes */
 static herr_t  H5FD__vfd_swmr_term(void);
@@ -217,6 +223,10 @@ done:
  *
  * Return:      SUCCEED/FAIL
  *
+ * Modifications:
+ *  Vailin Choi: 2/18/2022
+ *  VDS changes: Try opening metadata file and loading header/index if make_believe is FALSE.
+ *
  *-------------------------------------------------------------------------
  */
 static herr_t
@@ -235,30 +245,119 @@ H5FD__swmr_reader_open(H5FD_vfd_swmr_t *file)
     if (file->api_elapsed_ticks == NULL)
         HGOTO_ERROR(H5E_VFL, H5E_CANTALLOC, FAIL, "could not allocate API elapsed ticks")
 
-    /* Retry on opening the metadata file */
-    for (do_try         = H5_retry_init(&retry, H5FD_VFD_SWMR_MD_FILE_RETRY_MAX, H5_RETRY_DEFAULT_MINIVAL,
-                                H5_RETRY_DEFAULT_MAXIVAL);
-         do_try; do_try = H5_retry_next(&retry)) {
-        if ((file->md_fd = HDopen(file->md_file_path, O_RDONLY)) >= 0)
-            break;
-    }
+    if (!file->make_believe) {
+        /* Retry on opening the metadata file */
+        for (do_try         = H5_retry_init(&retry, H5FD_VFD_SWMR_MD_FILE_RETRY_MAX, H5_RETRY_DEFAULT_MINIVAL,
+                                    H5_RETRY_DEFAULT_MAXIVAL);
+             do_try; do_try = H5_retry_next(&retry)) {
+            if ((file->md_fd = HDopen(file->md_file_path_name, O_RDONLY)) >= 0)
+                break;
+        }
 
-    /* Exhaust all retries for opening the md file */
-    if (!do_try)
-        HGOTO_ERROR(H5E_VFL, H5E_OPENERROR, FAIL,
-                    "unable to open the metadata file after all retry attempts");
+        /* Exhaust all retries for opening the md file */
+        if (!do_try)
+            HGOTO_ERROR(H5E_VFL, H5E_OPENERROR, FAIL,
+                        "unable to open the metadata file after all retry attempts");
 
-    /* Retry on loading and decoding the header and index in the
-     *  metadata file
-     */
-    if (H5FD__vfd_swmr_load_hdr_and_idx(file, TRUE) < 0)
-        HGOTO_ERROR(H5E_VFL, H5E_CANTGET, FAIL, "unable to load/decode the md file header/index");
+        /* Retry on loading and decoding the header and index in the
+         *  metadata file
+         */
+        if (H5FD__vfd_swmr_load_hdr_and_idx(file, TRUE) < 0)
+            HGOTO_ERROR(H5E_VFL, H5E_CANTGET, FAIL, "unable to load/decode the md file header/index");
+    }
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5FD__swmr_reader_open() */
 
 /*-------------------------------------------------------------------------
+ *
+ * Function:    H5FD__vfd_swmr_build_md_path_name
+ *
+ * Purpose:     To construct the metadata file's full name based on config's
+ *              md_file_path and md_file_name.  See RFC for details.
+ *
+ *
+ * Return:      Success:        SUCCEED
+ *              Failure:        FAIL
+ *
+ * Programmer:  Vailin Choi -- 1/13/2022
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5FD__vfd_swmr_build_md_path_name(H5F_vfd_swmr_config_t *config, const char *hdf5_filename,
+                                  char *name /*out*/)
+{
+    size_t tot_len   = 0;
+    size_t tmp_len   = 0;
+    herr_t ret_value = SUCCEED; /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    if ((tot_len = HDstrlen(config->md_file_path)) != 0) {
+
+        /* md_file_path + '/' */
+        if (++tot_len > H5F__MAX_VFD_SWMR_FILE_NAME_LEN)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTCOPY, FAIL, "md_file_path and md_file_name exceeds maximum");
+        HDstrcat(name, config->md_file_path);
+        HDstrcat(name, "/");
+    }
+
+    if ((tmp_len = HDstrlen(config->md_file_name)) != 0) {
+        if ((tot_len += tmp_len) > H5F__MAX_VFD_SWMR_FILE_NAME_LEN)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTCOPY, FAIL, "md_file_path and md_file_name exceeds maximum");
+        HDstrcat(name, config->md_file_name);
+    }
+    else {
+        /* Automatic generation of metadata file name based on hdf5_filename + '.md' */
+        if ((tot_len += (HDstrlen(hdf5_filename) + 3)) > H5F__MAX_VFD_SWMR_FILE_NAME_LEN)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTCOPY, FAIL, "md_file_path and md_file_name maximum");
+
+        HDstrcat(name, hdf5_filename);
+        HDstrcat(name, VFD_SWMR_MD_SUFFIX);
+    }
+
+done:
+
+    FUNC_LEAVE_NOAPI(ret_value)
+
+} /* H5FD__vfd_swmr_build_md_path_name() */
+
+/*-------------------------------------------------------------------------
+ * Function:    H5FD__vfd_swmr_create_make_believe_data
+ *
+ * Purpose:     Set up pretend data when make_believe is true
+ *
+ * Return:      VOID
+ *
+ * Programmer:  Vailin Choi -- 1/13/2022
+ *
+ *-------------------------------------------------------------------------
+ */
+static void
+H5FD__vfd_swmr_create_make_believe_data(H5FD_vfd_swmr_t *_file)
+{
+    H5FD_vfd_swmr_t *file = (H5FD_vfd_swmr_t *)_file;
+
+    FUNC_ENTER_PACKAGE_NOERR
+
+    HDassert(file->make_believe);
+
+    /* Create make_believe data: empty header and index */
+    file->md_header.fs_page_size = 0;
+    file->md_header.tick_num     = 0;
+    file->md_header.index_offset = H5FD_MD_HEADER_SIZE;
+    file->md_header.index_length = H5FD_MD_INDEX_SIZE(0);
+
+    file->md_index.tick_num    = 0;
+    file->md_index.num_entries = 0;
+
+    FUNC_LEAVE_NOAPI_VOID
+
+} /* H5FD__vfd_swmr_create_make_believe_data() */
+
+/*-------------------------------------------------------------------------
  * Function:    H5FD__vfd_swmr_open
  *
  * Purpose:     Open the metadata file and the underlying HDF5 file
@@ -268,6 +367,11 @@ done:
  *                          caller, which is always H5FD_open().
  *              Failure:    NULL
  *
+ * Modifications:
+ *  Vailin Choi: 2/18/2022
+ *  VDS changes: --Build metadata file name
+ *               --Determine make_believe or not
+ *
  *-------------------------------------------------------------------------
  */
 static H5FD_t *
@@ -278,6 +382,7 @@ H5FD__vfd_swmr_open(const char *name, unsigned flags, hid_t fapl_id, haddr_t max
     H5P_genplist_t *       plist;
     H5F_vfd_swmr_config_t *vfd_swmr_config;
     H5FD_t *               ret_value = NULL; /* Return value     */
+    htri_t                 is_hdf5;
 
     FUNC_ENTER_PACKAGE
 
@@ -314,16 +419,32 @@ H5FD__vfd_swmr_open(const char *name, unsigned flags, hid_t fapl_id, haddr_t max
     file->hdf5_filename[sizeof(file->hdf5_filename) - 1] = '\0';
 
     /* Retain a copy of the metadata file name */
-    HDstrncpy(file->md_file_path, vfd_swmr_config->md_file_path, sizeof(file->md_file_path));
-    file->md_file_path[sizeof(file->md_file_path) - 1] = '\0';
+    if (H5FD__vfd_swmr_build_md_path_name(vfd_swmr_config, name, file->md_file_path_name) < 0)
+        HGOTO_ERROR(H5E_VFL, H5E_OPENERROR, NULL, "building md_file_path and md_file_name failed")
+
+    file->md_file_path_name[sizeof(file->md_file_path_name) - 1] = '\0';
 
     file->writer = vfd_swmr_config->writer;
 
-    /* Ensure that this is the reader */
-    if (!vfd_swmr_config->writer && H5FD__swmr_reader_open(file) < 0)
-        HGOTO_ERROR(H5E_VFL, H5E_OPENERROR, NULL, "perform reader-specific opening steps failed")
+    /* Make sure the hdf5 file exists and is valid */
+    is_hdf5 = H5F__is_hdf5(name, H5P_FILE_ACCESS_DEFAULT);
+
+    /* Ensure reader */
+    if (!vfd_swmr_config->writer) {
+        /* Metadata file does not exist, presume_posix is true, HDF5 file exist */
+        if (HDaccess(file->md_file_path_name, F_OK) < 0 && vfd_swmr_config->presume_posix_semantics &&
+            is_hdf5 == TRUE) {
+
+            file->make_believe = TRUE;
+            H5FD__vfd_swmr_create_make_believe_data(file);
+        }
+        if (H5FD__swmr_reader_open(file) < 0)
+            HGOTO_ERROR(H5E_VFL, H5E_OPENERROR, NULL, "perform reader-specific opening steps failed")
+    }
 
     /* Hard-wired to open the underlying HDF5 file with SEC2 */
+    /* H5FD_SEC2 is the default driver for H5P_FILE_ACCESS_DEFAULT except when
+       the environment variable HDF5_DRIVER is set to otherwise */
     if ((file->hdf5_file_lf = H5FD_open(name, flags, H5P_FILE_ACCESS_DEFAULT, maxaddr)) == NULL)
         HGOTO_ERROR(H5E_VFL, H5E_CANTOPENFILE, NULL, "can't set driver info");
 
@@ -453,10 +574,10 @@ H5FD__vfd_swmr_cmp(const H5FD_t *_f1, const H5FD_t *_f2)
     ret_value = H5FD_cmp(f1->hdf5_file_lf, f2->hdf5_file_lf);
 
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5FD_vfd__swmr_cmp() */
+} /* end H5FD__vfd__swmr_cmp() */
 
 /*-------------------------------------------------------------------------
- * Function:    H5FD_vfd_swmr_dedup
+ * Function:    H5FD_vfd_swmr_dedup (original description with H5P_FILE_ACCESS_ANY_VFD)
  *
  * Purpose:     Compare the already-opened VFD instance `_self` with the
  *              VFD instance `_other` newly-opened with file-access properties
@@ -497,6 +618,42 @@ H5FD__vfd_swmr_cmp(const H5FD_t *_f1, const H5FD_t *_f2)
  *              Failure:    NULL
  *-------------------------------------------------------------------------
  */
+/*-------------------------------------------------------------------------
+ * Function:    H5FD_vfd_swmr_dedup (modified version without H5P_FILE_ACCESS_ANY_VFD)
+ *
+ * Purpose:     Compare the already-opened VFD instance `_self` with the
+ *              VFD instance `_other` newly-opened with file-access properties
+ *              `fapl_id` and indicate whether the instances duplicate each
+ *              other, if they conflict with each other, or if they are
+ *              dissimilar.
+ *
+ *              If `_self` duplicates `_other`, return `_self`.
+ *
+ *              Return NULL on error, or if `_other` and `_self` refer to the
+ *              same file but the file-access properties, `fapl_id`, conflict
+ *              with the properties of `_self`.
+ *
+ *              If `_other` neither duplicates nor conflicts with `_self`,
+ *              then return `_other`.
+ *
+ * NOTE:        Judging duplicate/conflicting/dissimilar VFD instances
+ *
+ *              `_self` DUPLICATES `_other` if `_other` is also an instance
+ *              of SWMR class, the instances' lower files are equal under
+ *              `H5FD_cmp()`, and the file-access properties of `_self` match
+ *              `fapl_id`.
+ *
+ *              `_self` and `_other` CONFLICT if both are SWMR instances
+ *              referring to the same lower file, and their file-access
+ *              properties differ.
+ *
+ *              `_self` and `_other` CONFLICT if `_other` is not a SWMR
+ *              instance, it equals the lower file of `_self`.
+ *
+ * Return:      Success:    `_self' or `_other', as described above
+ *              Failure:    NULL
+ *-------------------------------------------------------------------------
+ */
 H5FD_t *
 H5FD_vfd_swmr_dedup(H5FD_t *_self, H5FD_t *_other, hid_t fapl_id)
 {
@@ -523,12 +680,6 @@ H5FD_vfd_swmr_dedup(H5FD_t *_self, H5FD_t *_other, hid_t fapl_id)
         if (H5FD_cmp(self->hdf5_file_lf, other->hdf5_file_lf) != 0)
             HGOTO_DONE(_other)
 
-        /* If fapl_id == _ANY_VFD, then the match between lower files is
-         * sufficient.
-         */
-        if (fapl_id == H5P_FILE_ACCESS_ANY_VFD)
-            HGOTO_DONE(_self)
-
         /* If fapl_id != _ANY_VFD, then we have either a duplicate or
          * a conflict.  If the VFD SWMR parameters match, then
          * return `self` to indicate a duplicate.  Otherwise, return
@@ -552,7 +703,7 @@ H5FD_vfd_swmr_dedup(H5FD_t *_self, H5FD_t *_other, hid_t fapl_id)
         HGOTO_ERROR(H5E_VFL, H5E_CANTGET, NULL, "inconsistent VFD SWMR config")
     }
     else if (H5FD_cmp(self->hdf5_file_lf, _other) == 0)
-        ret_value = (fapl_id == H5P_FILE_ACCESS_ANY_VFD) ? _self : NULL;
+        ret_value = NULL;
     else
         ret_value = _other;
 
@@ -752,6 +903,11 @@ done:
  *                          buffer BUF.
  *              Failure:    FAIL, Contents of buffer BUF are undefined.
  *
+ * Modifications:
+ *  Vailin Choi: 2/18/2022
+ *  VDS changes: If fs_page_size is 0, i.e. in make_believe state,
+ *               read from the underlying HDF5 file
+ *
  *-------------------------------------------------------------------------
  */
 static herr_t
@@ -780,10 +936,17 @@ H5FD__vfd_swmr_read(H5FD_t *_file, H5FD_mem_t type, hid_t H5_ATTR_UNUSED dxpl_id
     num_entries  = file->md_index.num_entries;
     fs_page_size = file->md_header.fs_page_size;
 
-    /* Try finding the addr from the index */
-    target_page = addr / fs_page_size;
+    if (!fs_page_size) {
+        HDassert(!num_entries);
+        HDassert(file->make_believe);
+        entry = NULL;
+    }
+    else {
+        /* Try finding the addr from the index */
+        target_page = addr / fs_page_size;
 
-    entry = H5FD_vfd_swmr_pageno_to_mdf_idx_entry(index, num_entries, target_page, FALSE);
+        entry = H5FD_vfd_swmr_pageno_to_mdf_idx_entry(index, num_entries, target_page, FALSE);
+    }
 
     if (entry == NULL) {
         /* Cannot find addr in index, read from the underlying hdf5 file */
@@ -1008,6 +1171,10 @@ done:
  * Return:      Success:    SUCCEED
  *              Failure:    FAIL
  *
+ * Modifications:
+ *  Vailin Choi: 2/18/2022
+ *  VDS changes: Update the header's fs_page size if it is still 0
+ *
  *-------------------------------------------------------------------------
  */
 static herr_t
@@ -1113,6 +1280,14 @@ H5FD__vfd_swmr_load_hdr_and_idx(H5FD_vfd_swmr_t *file, hbool_t open)
     md_index.entries = NULL;
 
 done:
+    /* Need to update the header's fs_page_size if it is still 0
+       because it is possible that md_header.tick_num == file->md_header.tick_num
+       and the loading is not done */
+    if (ret_value == SUCCEED && !file->md_header.fs_page_size) {
+        HDassert(md_header.fs_page_size);
+        HDassert(file->make_believe);
+        file->md_header.fs_page_size = md_header.fs_page_size;
+    }
 
     FUNC_LEAVE_NOAPI(ret_value)
 
@@ -1501,3 +1676,138 @@ H5FD_vfd_swmr_record_elapsed_ticks(H5FD_t *_file, uint64_t elapsed)
 
     FUNC_LEAVE_NOAPI_VOID
 } /* end H5FD_vfd_swmr_record_elapsed_ticks() */
+
+/*-------------------------------------------------------------------------
+ * Function:    H5FD_vfd_swmr_get_md_name
+ *
+ * Purpose:     To retrieve the metadata file's full name
+ *
+ * Return:      VOID
+ *
+ * Programmer:  Vailin Choi; 02/18/2022
+ *
+ *-------------------------------------------------------------------------
+ *
+ */
+void
+H5FD_vfd_swmr_get_md_path_name(H5FD_t *_file, char **name)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    H5FD_vfd_swmr_t *file = (H5FD_vfd_swmr_t *)_file;
+
+    *name = H5MM_xstrdup(file->md_file_path_name);
+
+    FUNC_LEAVE_NOAPI_VOID
+
+} /* H5FD_vfd_swmr_get_md_path_name() */
+
+/*-------------------------------------------------------------------------
+ * Function:    H5FD_vfd_swmr_get_make_believe
+ *
+ * Purpose:     To retrieve the value of make_believe
+ *
+ * Return:      TRUE/FALSE
+ *
+ * Programmer:  Vailin Choi; 02/18/2022
+ *
+ *-------------------------------------------------------------------------
+ *
+ */
+hbool_t
+H5FD_vfd_swmr_get_make_believe(H5FD_t *_file)
+{
+    H5FD_vfd_swmr_t *file = (H5FD_vfd_swmr_t *)_file;
+
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    HDassert(file);
+
+    FUNC_LEAVE_NOAPI(file->make_believe)
+
+} /* H5FD_vfd_swmr_get_make_believe() */
+
+/*-------------------------------------------------------------------------
+ * Function:    H5FD_vfd_swmr_set_make_believe
+ *
+ * Purpose:     To set the VFD's make believe to the
+ *              parameter "make_believe"
+ *
+ * Return:      VOID
+ *
+ * Programmer:  Vailin Choi; 02/18/2022
+ *
+ *-------------------------------------------------------------------------
+ *
+ */
+void
+H5FD_vfd_swmr_set_make_believe(H5FD_t *_file, hbool_t make_believe)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    H5FD_vfd_swmr_t *file = (H5FD_vfd_swmr_t *)_file;
+
+    HDassert(file);
+
+    /* Set return value */
+    file->make_believe = make_believe;
+
+    FUNC_LEAVE_NOAPI_VOID
+
+} /* H5FD_vfd_swmr_make_believe() */
+
+/*-------------------------------------------------------------------------
+ * Function:    H5FD_vfd_swmr_assess_make_believe
+ *
+ * Purpose:     To determine whether continuing with make_believe or not.
+ *              Return TRUE:
+ *              --if metadata file does not exist, continue with make_believe
+ *              Return FALSE:
+ *              --if metadata file exists and can be opened successfully,
+ *                discontinue with make_believe
+ *              Return FAIL:
+ *              --error in opening the metadata file
+ *
+ *
+ * Return:      TRUE/FALSE/FAIL
+ *
+ * Programmer:  Vailin Choi; 02/18/2022
+ *-------------------------------------------------------------------------
+ */
+htri_t
+H5FD_vfd_swmr_assess_make_believe(H5FD_t *_file)
+{
+    H5FD_vfd_swmr_t *file = (H5FD_vfd_swmr_t *)_file; /* VFD SWMR file struct */
+    h5_retry_t       retry;
+    hbool_t          do_try;           /* more tries remain */
+    htri_t           ret_value = TRUE; /* Return value  */
+
+    FUNC_ENTER_NOAPI(FALSE)
+
+    HDassert(file->make_believe);
+
+    if (HDaccess(file->md_file_path_name, F_OK) >= 0) {
+        /* MD file exists now, proceed to open it */
+        HDassert(file->md_fd < 0);
+
+        /* Retry on opening the metadata file */
+        for (do_try         = H5_retry_init(&retry, H5FD_VFD_SWMR_MD_FILE_RETRY_MAX, H5_RETRY_DEFAULT_MINIVAL,
+                                    H5_RETRY_DEFAULT_MAXIVAL);
+             do_try; do_try = H5_retry_next(&retry)) {
+            if ((file->md_fd = HDopen(file->md_file_path_name, O_RDONLY)) >= 0)
+                break;
+        }
+
+        /* Exhaust all retries for opening the md file */
+        if (!do_try)
+            HGOTO_ERROR(H5E_VFL, H5E_OPENERROR, FAIL,
+                        "unable to open the metadata file after all retry attempts");
+
+        /* Succeed in opening the MD file, discontinue make_believe */
+        ret_value = FALSE;
+    }
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+
+} /* end H5FD_vfd_swmr_assess_make_believe() */
diff --git a/src/H5Fint.c b/src/H5Fint.c
index 2822d9d..68c53f2 100644
--- a/src/H5Fint.c
+++ b/src/H5Fint.c
@@ -1828,10 +1828,25 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id)
 
     FUNC_ENTER_NOAPI(NULL)
 
+    /*
+     * If the driver has a 'cmp' method then the driver is capable of
+     * determining when two file handles refer to the same file and the
+     * library can insure that when the application opens a file twice
+     * that the two handles coordinate their operations appropriately.
+     * Otherwise it is the application's responsibility to never open the
+     * same file more than once at a time.
+     */
+    if (NULL == (drvr = H5FD_get_class(fapl_id)))
+        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, NULL, "unable to retrieve VFL class")
+
     /* Get the file access property list, for future queries */
     if (NULL == (a_plist = (H5P_genplist_t *)H5I_object(fapl_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not file access property list")
 
+    /* Check if we are using file locking */
+    if (H5F__check_if_using_file_locks(a_plist, &use_file_locking) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, NULL, "unable to get file locking flag")
+
     /* Allocate space for VFD SWMR configuration info */
     if (NULL == (vfd_swmr_config_ptr = H5MM_calloc(sizeof(H5F_vfd_swmr_config_t))))
         HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, NULL, "can't allocate memory for mdc log file name")
@@ -1854,25 +1869,6 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id)
     }
 
     /*
-     * If the driver has a 'cmp' method then the driver is capable of
-     * determining when two file handles refer to the same file and the
-     * library can insure that when the application opens a file twice
-     * that the two handles coordinate their operations appropriately.
-     * Otherwise it is the application's responsibility to never open the
-     * same file more than once at a time.
-     */
-    if (NULL == (drvr = H5FD_get_class(fapl_id)))
-        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, NULL, "unable to retrieve VFL class")
-
-    /* Get the file access property list, for future queries */
-    if (NULL == (a_plist = (H5P_genplist_t *)H5I_object(fapl_id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not file access property list")
-
-    /* Check if we are using file locking */
-    if (H5F__check_if_using_file_locks(a_plist, &use_file_locking) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, NULL, "unable to get file locking flag")
-
-    /*
      * Opening a file is a two step process. First we try to open the
      * file in a way which doesn't affect its state (like not truncating
      * or creating it) so we can compare it with files that are already
diff --git a/src/H5Fio.c b/src/H5Fio.c
index ca069e0..7193199 100644
--- a/src/H5Fio.c
+++ b/src/H5Fio.c
@@ -83,7 +83,8 @@
 herr_t
 H5F_shared_block_read(H5F_shared_t *f_sh, H5FD_mem_t type, haddr_t addr, size_t size, void *buf /*out*/)
 {
-    herr_t ret_value = SUCCEED; /* Return value */
+    H5FD_mem_t map_type  = type;    /* Mapped memory type */
+    herr_t     ret_value = SUCCEED; /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
 
@@ -96,8 +97,12 @@ H5F_shared_block_read(H5F_shared_t *f_sh, H5FD_mem_t type, haddr_t addr, size_t
     if (H5F_addr_le(f_sh->tmp_addr, (addr + size)))
         HGOTO_ERROR(H5E_IO, H5E_BADRANGE, FAIL, "attempting I/O in temporary file space")
 
+    if (!H5F_SHARED_USE_VFD_SWMR(f_sh))
+        /* Treat global heap as raw data */
+        map_type = (type == H5FD_MEM_GHEAP) ? H5FD_MEM_DRAW : type;
+
     /* Pass through page buffer layer */
-    if (H5PB_read(f_sh, type, addr, size, buf) < 0)
+    if (H5PB_read(f_sh, map_type, addr, size, buf) < 0)
         HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "read through page buffer failed")
 
 done:
@@ -141,7 +146,8 @@ H5F_block_read(H5F_t *f, H5FD_mem_t type, haddr_t addr, size_t size, void *buf /
 herr_t
 H5F_shared_block_write(H5F_shared_t *f_sh, H5FD_mem_t type, haddr_t addr, size_t size, const void *buf)
 {
-    herr_t ret_value = SUCCEED; /* Return value */
+    H5FD_mem_t map_type  = type;    /* Mapped memory type */
+    herr_t     ret_value = SUCCEED; /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
 
@@ -155,8 +161,12 @@ H5F_shared_block_write(H5F_shared_t *f_sh, H5FD_mem_t type, haddr_t addr, size_t
     if (H5F_addr_le(f_sh->tmp_addr, (addr + size)))
         HGOTO_ERROR(H5E_IO, H5E_BADRANGE, FAIL, "attempting I/O in temporary file space")
 
+    if (!H5F_SHARED_USE_VFD_SWMR(f_sh))
+        /* Treat global heap as raw data */
+        map_type = (type == H5FD_MEM_GHEAP) ? H5FD_MEM_DRAW : type;
+
     /* Pass through page buffer layer */
-    if (H5PB_write(f_sh, type, addr, size, buf) < 0)
+    if (H5PB_write(f_sh, map_type, addr, size, buf) < 0)
         HGOTO_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "write through page buffer failed")
 
 done:
diff --git a/src/H5Fpkg.h b/src/H5Fpkg.h
index ca714c1..95854cb 100644
--- a/src/H5Fpkg.h
+++ b/src/H5Fpkg.h
@@ -512,22 +512,24 @@ struct H5F_shared_t {
     uint32_t                   old_mdf_idx_entries_used;
 
     /* Metadata file and updater file for VFD SWMR writer */
-    int vfd_swmr_md_fd; /* POSIX: file descriptor for the
-                         * metadata file or -1 if the metadata file
-                         * is not currently open.
-                         * The vfd_swmr_config.generate_updater_files
-                         * is FALSE.
-                         */
-                        /* NFS:
-                         * The vfd_swmr_config.generate_updater_files
-                         * is TRUE and:
-                         * --if vfd_swmr_config.writer is FALSE,
-                         * this field is the file descriptor of the local
-                         * copy of the metadata file, or -1 if the local
-                         * copy is not currently open.
-                         * --if vfd_swmr_config.writer is TRUE, this field
-                         * is not used and is set to -1.
-                         */
+    int vfd_swmr_md_fd;      /* POSIX: file descriptor for the
+                              * metadata file or -1 if the metadata file
+                              * is not currently open.
+                              * The vfd_swmr_config.generate_updater_files
+                              * is FALSE.
+                              */
+                             /* NFS:
+                              * The vfd_swmr_config.generate_updater_files
+                              * is TRUE and:
+                              * --if vfd_swmr_config.writer is FALSE,
+                              * this field is the file descriptor of the local
+                              * copy of the metadata file, or -1 if the local
+                              * copy is not currently open.
+                              * --if vfd_swmr_config.writer is TRUE, this field
+                              * is not used and is set to -1.
+                              */
+    char *md_file_path_name; /* Name composed of md_file_path and md_file_name from vfd_swmr_config */
+
     H5F_generate_md_ck_t generate_md_ck_cb;
     /* For testing only:
      * Invoke the user-defined callback if exists to
diff --git a/src/H5Fprivate.h b/src/H5Fprivate.h
index ffc369b..c594ed8 100644
--- a/src/H5Fprivate.h
+++ b/src/H5Fprivate.h
@@ -374,6 +374,7 @@ typedef struct H5F_t H5F_t;
 #define H5F_THRESHOLD(F)               ((F)->shared->threshold)
 #define H5F_PGEND_META_THRES(F)        ((F)->shared->fs.pgend_meta_thres)
 #define H5F_POINT_OF_NO_RETURN(F)      ((F)->shared->fs.point_of_no_return)
+#define H5F_SHARED_USE_VFD_SWMR(F_SH)  ((F_SH)->vfd_swmr)
 #define H5F_USE_VFD_SWMR(F)            ((F)->shared->vfd_swmr)
 #define H5F_NULL_FSM_ADDR(F)           ((F)->shared->null_fsm_addr)
 #define H5F_GET_MIN_DSET_OHDR(F)       ((F)->shared->crt_dset_min_ohdr_flag)
@@ -438,6 +439,7 @@ typedef struct H5F_t H5F_t;
 #define H5F_THRESHOLD(F)               (H5F_get_threshold(F))
 #define H5F_PGEND_META_THRES(F)        (H5F_get_pgend_meta_thres(F))
 #define H5F_POINT_OF_NO_RETURN(F)      (H5F_get_point_of_no_return(F))
+#define H5F_SHARED_USE_VFD_SWMR(F_SH)  (H5F_shared_get_use_vfd_swmr(F_SH))
 #define H5F_USE_VFD_SWMR(F)            (H5F_get_use_vfd_swmr(F))
 #define H5F_NULL_FSM_ADDR(F)           (H5F_get_null_fsm_addr(F))
 #define H5F_GET_MIN_DSET_OHDR(F)       (H5F_get_min_dset_ohdr(F))
@@ -628,6 +630,7 @@ typedef struct H5F_t H5F_t;
         /* int32_t    version                 = */ 0,                                                        \
         /* int32_t    tick_len                = */ 0,                                                        \
         /* int32_t    max_lag                 = */ 0,                                                        \
+        /* hbool_t    presume_posix_semantics = */ FALSE,                                                    \
         /* hbool_t    vfd_swmr_writer         = */ FALSE,                                                    \
         /* hbool_t    maintain_metadata_file  = */ FALSE,                                                    \
         /* hbool_t    generate_updater_files  = */ FALSE,                                                    \
@@ -635,6 +638,7 @@ typedef struct H5F_t H5F_t;
         /* int32_t    md_pages_reserved       = */ 0,                                                        \
         /* int32_t    pb_expansion_threshold  = */ 0,                                                        \
         /* char       md_file_path[]          = */ "",                                                       \
+        /* char       md_file_name[]          = */ "",                                                       \
         /* char       updater_file_path[]     = */ "",                                                       \
         /* char       log_file_path[]         = */ ""                                                        \
     }
diff --git a/src/H5Fpublic.h b/src/H5Fpublic.h
index e9d3340..0e8eda6 100644
--- a/src/H5Fpublic.h
+++ b/src/H5Fpublic.h
@@ -271,6 +271,20 @@ typedef herr_t (*H5F_flush_cb_t)(hid_t object_id, void *udata);
  *          between the writer and the readers.  This value must be at least 3,
  *          with 10 being the recommended minimum value.
  *
+ *      presume_posix_semantics
+ *          A boolean flag that is only relevant to the reader.
+ *          This flag should be set to TRUE if both of the following conditions hold:
+ *          1) Both the metadata file and HDF5 file are being written on a POSIX
+ *             file system that is local to the reader.
+ *          2) The metadata file is being maintained directly by the VFD SWMR
+ *             writer (i.e. without use of updater files and the auxiliary process.)
+ *          If this flag is FALSE, the VFD SWMR reader must make the two adjustments:
+ *          1) Per legacy SWMR, the VFD that reads the HDF5 file proper must allow
+ *             reads past EOF without error.
+ *          2) The VFD SWMR reader is not permitted to open an existing HDF5 file
+ *             either before the VFD SWMR writer has opened it, or after it has
+ *             closed it.
+ *
  *      writer:
  *          A boolean flag indicating whether the file opened with this FAPL entry
  *          will be opened R/W. (i.e. as a VFD SWMR writer)
@@ -333,9 +347,19 @@ typedef herr_t (*H5F_flush_cb_t)(hid_t object_id, void *udata);
  *
  *      md_file_path:
  *          If both the writer and maintain_metadata_file fields are TRUE, this
- *          field contains the path of the metadata file.
- *          If writer is FALSE, this field contains the path of the (possibly
- *          local copy of the) metadata file.
+ *          field contains the path but not the name of the metadata file.
+ *          If writer is FALSE, this field contains the path (but not the name)
+ *          of the (possibly local copy of the) metadata file.
+ *
+ *      md_file_name:
+ *          If both the writer and maintain_metadata_file fields are TRUE, this
+ *          field is defined, and must contain the name (but not the path) of
+ *          the metadata file, or NULL.
+ *          If writer is FALSE, this field is defined, and must contain either
+ *          the name (but not the path) of the metadata file, or NULL.
+ *          If the field is defined but NULL, the metadata file name is
+ *          generated by adding the ".md" suffix to the HDF5 file name.
+ *          If the field is not NULL, the metadata file name is used as provided.
  *
  *      updater_file_path:
  *          If generate_updater_files is TRUE, the contents of this field depends
@@ -353,6 +377,7 @@ typedef struct H5F_vfd_swmr_config_t {
     int32_t  version;
     uint32_t tick_len;
     uint32_t max_lag;
+    hbool_t  presume_posix_semantics;
     hbool_t  writer;
     hbool_t  maintain_metadata_file;
     hbool_t  generate_updater_files;
@@ -360,6 +385,7 @@ typedef struct H5F_vfd_swmr_config_t {
     uint32_t md_pages_reserved;
     uint32_t pb_expansion_threshold;
     char     md_file_path[H5F__MAX_VFD_SWMR_FILE_NAME_LEN + 1];
+    char     md_file_name[H5F__MAX_VFD_SWMR_FILE_NAME_LEN + 1];
     char     updater_file_path[H5F__MAX_VFD_SWMR_FILE_NAME_LEN + 1];
     char     log_file_path[H5F__MAX_VFD_SWMR_FILE_NAME_LEN + 1];
 } H5F_vfd_swmr_config_t;
diff --git a/src/H5Fquery.c b/src/H5Fquery.c
index acdf521..22b9f78 100644
--- a/src/H5Fquery.c
+++ b/src/H5Fquery.c
@@ -1344,6 +1344,25 @@ H5F_get_file_locking(const H5F_t *f)
 } /* end H5F_get_file_locking */
 
 /*-------------------------------------------------------------------------
+ * Function: H5F_shared_get_use_vfd_swmr
+ *
+ * Purpose:  Determine if VFD SWMR is enabled for this file.
+ *
+ * Return:   TRUE/FALSE
+ *-------------------------------------------------------------------------
+ */
+unsigned
+H5F_shared_get_use_vfd_swmr(const H5F_shared_t *f_sh)
+{
+    /* Use FUNC_ENTER_NOAPI_NOINIT_NOERR here to avoid performance issues */
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    HDassert(f_sh);
+
+    FUNC_LEAVE_NOAPI(f_sh->vfd_swmr)
+} /* end H5F_shared_get_use_vfd_swmr() */
+
+/*-------------------------------------------------------------------------
  * Function: H5F_get_use_vfd_swmr
  *
  * Purpose:  Determine if VFD SWMR is enabled for this file.
diff --git a/src/H5Ftest.c b/src/H5Ftest.c
index 0213cd1..86b3c0b 100644
--- a/src/H5Ftest.c
+++ b/src/H5Ftest.c
@@ -338,11 +338,11 @@ H5F__vfd_swmr_writer_create_open_flush_test(hid_t file_id, hbool_t file_create)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file")
 
     /* Open the metadata file */
-    if ((md_fd = HDopen(f->shared->vfd_swmr_config.md_file_path, O_RDONLY)) < 0)
+    if ((md_fd = HDopen(f->shared->md_file_path_name, O_RDONLY)) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "error opening metadata file")
 
     /* Verify the minimum size for the metadata file */
-    if (HDstat(f->shared->vfd_swmr_config.md_file_path, &stat_buf) < 0)
+    if (HDstat(f->shared->md_file_path_name, &stat_buf) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "unable to stat the metadata file")
 
     if (file_create) { /* Creating file */
@@ -634,7 +634,7 @@ H5F__vfd_swmr_writer_md_test(hid_t file_id, unsigned num_entries, H5FD_vfd_swmr_
         HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "incorrect # of entries in the delayed list")
 
     /* Open the metadata file */
-    if ((md_fd = HDopen(f->shared->vfd_swmr_config.md_file_path, O_RDONLY)) < 0)
+    if ((md_fd = HDopen(f->shared->md_file_path_name, O_RDONLY)) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "error opening metadata file")
 
     /* Decode the header in the metadata file */
diff --git a/src/H5Fvfd_swmr.c b/src/H5Fvfd_swmr.c
index cd3a345..9c4360e 100644
--- a/src/H5Fvfd_swmr.c
+++ b/src/H5Fvfd_swmr.c
@@ -186,9 +186,11 @@ H5F_vfd_swmr_init(H5F_t *f, hbool_t file_create)
         shared->vfd_swmr_writer = TRUE;
         shared->tick_num        = 0;
 
-        /* Create the metadata file */
-        if (((shared->vfd_swmr_md_fd = HDopen(shared->vfd_swmr_config.md_file_path,
-                                              O_CREAT | O_RDWR | O_TRUNC, H5_POSIX_CREATE_MODE_RW))) < 0)
+        /* Retrieve the metadata filename built with md_file_path and md_file_name */
+        H5FD_vfd_swmr_get_md_path_name(f->shared->lf, &shared->md_file_path_name);
+
+        if (((shared->vfd_swmr_md_fd = HDopen(shared->md_file_path_name, O_CREAT | O_RDWR | O_TRUNC,
+                                              H5_POSIX_CREATE_MODE_RW))) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "unable to create the metadata file")
 
         md_size = (hsize_t)shared->vfd_swmr_config.md_pages_reserved * shared->fs_page_size;
@@ -215,7 +217,7 @@ H5F_vfd_swmr_init(H5F_t *f, hbool_t file_create)
 
         /* For VFD SWMR testing: invoke callback if set to generate metadata file checksum */
         if (shared->generate_md_ck_cb) {
-            if (shared->generate_md_ck_cb(shared->vfd_swmr_config.md_file_path, shared->updater_seq_num) < 0)
+            if (shared->generate_md_ck_cb(shared->md_file_path_name, shared->updater_seq_num) < 0)
                 HGOTO_ERROR(H5E_FILE, H5E_SYSTEM, FAIL, "error from generate_md_ck_cb()")
         }
 
@@ -331,14 +333,16 @@ H5F_vfd_swmr_close_or_flush(H5F_t *f, hbool_t closing)
 
         /* For VFD SWMR testing: invoke callback if set to generate metadata file checksum */
         if (shared->generate_md_ck_cb) {
-            if (shared->generate_md_ck_cb(shared->vfd_swmr_config.md_file_path, shared->updater_seq_num) < 0)
+            if (shared->generate_md_ck_cb(shared->md_file_path_name, shared->updater_seq_num) < 0)
                 HGOTO_ERROR(H5E_FILE, H5E_SYSTEM, FAIL, "error from generate_md_ck_cb()")
         }
 
         /* Unlink the md file */
-        if (HDunlink(shared->vfd_swmr_config.md_file_path) < 0)
+        if (HDunlink(shared->md_file_path_name) < 0)
             HSYS_GOTO_ERROR(H5E_FILE, H5E_CANTREMOVE, FAIL, "unable to unlink the metadata file")
 
+        shared->md_file_path_name = (char *)H5MM_xfree(shared->md_file_path_name);
+
         /* Close the free-space manager for the metadata file */
         if (H5MV_close(f) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_CANTRELEASE, FAIL,
@@ -571,7 +575,7 @@ H5F_update_vfd_swmr_metadata_file(H5F_t *f, uint32_t num_entries, H5FD_vfd_swmr_
 
     /* For VFD SWMR testing: invoke callback if set to generate metadata file checksum */
     if (shared->generate_md_ck_cb) {
-        if (shared->generate_md_ck_cb(shared->vfd_swmr_config.md_file_path, shared->updater_seq_num) < 0)
+        if (shared->generate_md_ck_cb(shared->md_file_path_name, shared->updater_seq_num) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_SYSTEM, FAIL, "error from generate_md_ck_cb()")
     }
 
@@ -1031,6 +1035,14 @@ H5F_vfd_swmr_writer_dump_index(H5F_shared_t *shared)
  *           9) Increment the tick, and update the end of tick.
  *
  * Return:   SUCCEED/FAIL
+ *
+ * Programmer: John Mainzer 12/29/18
+ *
+ * Changes:
+ *  VDS changes: Check make_believe whether to continue the same or
+ *               get out of make_believe and load header/index.
+ *               For details, see RFC for VDS changes.
+ *
  *-------------------------------------------------------------------------
  */
 herr_t
@@ -1053,6 +1065,7 @@ H5F_vfd_swmr_reader_end_of_tick(H5F_t *f, hbool_t entering_api)
     herr_t   ret_value = SUCCEED;
     uint32_t i, j, nchanges;
     H5FD_t * file = shared->lf;
+    htri_t   ret;
 
     FUNC_ENTER_NOAPI(FAIL)
 
@@ -1071,9 +1084,35 @@ H5F_vfd_swmr_reader_end_of_tick(H5F_t *f, hbool_t entering_api)
      *    so as to detect the need to allocate more space for the
      *    index.
      */
-    if (H5FD_vfd_swmr_get_tick_and_idx(file, TRUE, &tmp_tick_num, &vfd_entries, NULL) < 0)
 
-        HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "error in retrieving tick_num from driver")
+    /* Check if make_believe is set */
+    if (H5FD_vfd_swmr_get_make_believe(file)) {
+
+        /* Return value is TRUE: metadata file is not found, continue with make_believe
+           and skip eot processing */
+        if ((ret = H5FD_vfd_swmr_assess_make_believe(file)) == TRUE) {
+            /* Skip most of the EOT processing */
+            goto reader_update_eot;
+        }
+        else if (ret == FAIL)
+            HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "error in assessing make_believe from driver")
+
+        /* Return value is FALSE i.e. found the metadata file */
+        HDassert(!ret);
+
+        /* Try to load the metadata file header and index */
+        if (H5FD_vfd_swmr_get_tick_and_idx(file, TRUE, &tmp_tick_num, &vfd_entries, NULL) < 0)
+            HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "error in retrieving tick_num from driver")
+
+        /* Set make_believe to FALSE;
+           get out from make_believe state, continue normal processing */
+        H5FD_vfd_swmr_set_make_believe(file, FALSE);
+    }
+    else {
+        /* make_believe is not set, continue normal processing */
+        if (H5FD_vfd_swmr_get_tick_and_idx(file, TRUE, &tmp_tick_num, &vfd_entries, NULL) < 0)
+            HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "error in retrieving tick_num from driver")
+    }
 
     /* This is ok if we're entering the API, but it should
      * not happen if we're exiting the API.
@@ -1288,6 +1327,8 @@ H5F_vfd_swmr_reader_end_of_tick(H5F_t *f, hbool_t entering_api)
         }
     }
 
+reader_update_eot:
+
     /* Remove the entry from the EOT queue */
     if (H5F_vfd_swmr_remove_entry_eot(f) < 0)
         HDONE_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "unable to remove entry from EOT queue")
@@ -2305,7 +2346,8 @@ H5F__generate_updater_file(H5F_t *f, uint32_t num_entries, uint16_t flags, uint8
     if (sz > H5F__MAX_VFD_SWMR_FILE_NAME_LEN)
         HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "string passed to snprintf would be truncated")
     newname[H5F__MAX_VFD_SWMR_FILE_NAME_LEN - 1] = '\0';
-    HDrename(namebuf, newname);
+    if (HDrename(namebuf, newname) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "error from renaming the updater file")
 
     ++shared->updater_seq_num;
 
diff --git a/src/H5Pfapl.c b/src/H5Pfapl.c
index 7d3cf57..f900965 100644
--- a/src/H5Pfapl.c
+++ b/src/H5Pfapl.c
@@ -863,12 +863,6 @@ H5P__facc_reg_prop(H5P_genclass_t *pclass)
                            H5F_ACS_IGNORE_DISABLED_FILE_LOCKS_DEC, NULL, NULL, NULL, NULL) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
 
-    if (H5P_LST_FILE_ACCESS_ANY_VFD_g == H5I_INVALID_HID) {
-        H5P_LST_FILE_ACCESS_ANY_VFD_g = H5P_create_id(pclass, false);
-        if (H5P_LST_FILE_ACCESS_ANY_VFD_g == H5I_INVALID_HID) {
-            HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't create any-vfd fapl");
-        }
-    }
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5P__facc_reg_prop() */
@@ -4637,6 +4631,7 @@ H5P__facc_vfd_swmr_config_enc(const void *value, void **_pp, size_t *size)
         INT32ENCODE(*pp, (int32_t)config->version);
         INT32ENCODE(*pp, (int32_t)config->tick_len);
         INT32ENCODE(*pp, (int32_t)config->max_lag);
+        H5_ENCODE_UNSIGNED(*pp, config->presume_posix_semantics);
         H5_ENCODE_UNSIGNED(*pp, config->writer);
         H5_ENCODE_UNSIGNED(*pp, config->maintain_metadata_file);
         H5_ENCODE_UNSIGNED(*pp, config->generate_updater_files);
@@ -4645,6 +4640,8 @@ H5P__facc_vfd_swmr_config_enc(const void *value, void **_pp, size_t *size)
         INT32ENCODE(*pp, (int32_t)config->pb_expansion_threshold);
         HDmemcpy(*pp, (const uint8_t *)(config->md_file_path), (size_t)(H5F__MAX_VFD_SWMR_FILE_NAME_LEN + 1));
         *pp += H5F__MAX_VFD_SWMR_FILE_NAME_LEN + 1;
+        HDmemcpy(*pp, (const uint8_t *)(config->md_file_name), (size_t)(H5F__MAX_VFD_SWMR_FILE_NAME_LEN + 1));
+        *pp += H5F__MAX_VFD_SWMR_FILE_NAME_LEN + 1;
         HDmemcpy(*pp, (const uint8_t *)(config->updater_file_path),
                  (size_t)(H5F__MAX_VFD_SWMR_FILE_NAME_LEN + 1));
         *pp += H5F__MAX_VFD_SWMR_FILE_NAME_LEN + 1;
@@ -4655,7 +4652,7 @@ H5P__facc_vfd_swmr_config_enc(const void *value, void **_pp, size_t *size)
     } /* end if */
 
     /* Compute encoded size */
-    *size += ((5 * sizeof(int32_t)) + (4 * sizeof(unsigned)) + (3 * (H5F__MAX_VFD_SWMR_FILE_NAME_LEN + 1)));
+    *size += ((5 * sizeof(int32_t)) + (5 * sizeof(unsigned)) + (4 * (H5F__MAX_VFD_SWMR_FILE_NAME_LEN + 1)));
 
     FUNC_LEAVE_NOAPI(SUCCEED)
 } /* end H5P__facc_vfd_swmr_config_enc() */
@@ -4694,6 +4691,7 @@ H5P__facc_vfd_swmr_config_dec(const void **_pp, void *_value)
     INT32DECODE(*pp, config->version);
     UINT32DECODE(*pp, config->tick_len);
     UINT32DECODE(*pp, config->max_lag);
+    UINT32DECODE(*pp, config->presume_posix_semantics);
 
     H5_DECODE_UNSIGNED(*pp, config->writer);
     H5_DECODE_UNSIGNED(*pp, config->maintain_metadata_file);
@@ -4707,6 +4705,9 @@ H5P__facc_vfd_swmr_config_dec(const void **_pp, void *_value)
     HDstrcpy(config->md_file_path, (const char *)(*pp));
     *pp += H5F__MAX_VFD_SWMR_FILE_NAME_LEN + 1;
 
+    HDstrcpy(config->md_file_name, (const char *)(*pp));
+    *pp += H5F__MAX_VFD_SWMR_FILE_NAME_LEN + 1;
+
     HDstrcpy(config->updater_file_path, (const char *)(*pp));
     *pp += H5F__MAX_VFD_SWMR_FILE_NAME_LEN + 1;
 
@@ -6257,14 +6258,13 @@ H5Pset_vfd_swmr_config(hid_t plist_id, H5F_vfd_swmr_config_t *config_ptr)
                         "either maintain_metadata_file or generate_updater_files must be TRUE")
     }
 
-    if ((config_ptr->writer && config_ptr->maintain_metadata_file) || !config_ptr->writer) {
-        /* Must provide the path and base name of the metadata file */
-        name_len = HDstrlen(config_ptr->md_file_path);
-        if (name_len == 0)
-            HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, FAIL, "md_file_path is empty")
-        else if (name_len > H5F__MAX_VFD_SWMR_FILE_NAME_LEN)
-            HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, FAIL, "md_file_path is too long")
-    }
+    /* md_file_path can be "" or a name (+"/")*/
+    /* md_file_name can be "" (+ ".md") or a name */
+    /* <md_file_path, md_file_name> pattern: <null, null> <null, name> <name, null> <name, name> */
+    /* Can only validate for <null, name>, <name, name> cases */
+    name_len = HDstrlen(config_ptr->md_file_path) + HDstrlen(config_ptr->md_file_name);
+    if (name_len > H5F__MAX_VFD_SWMR_FILE_NAME_LEN)
+        HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, FAIL, "md_file_name + md_file_path is too long")
 
     if (config_ptr->writer && config_ptr->generate_updater_files) {
         /* Must provide the path and base name of the metadata updater files */
diff --git a/src/H5Pint.c b/src/H5Pint.c
index 400795a..da8ca1c 100644
--- a/src/H5Pint.c
+++ b/src/H5Pint.c
@@ -182,7 +182,6 @@ hid_t H5P_LST_DATASET_CREATE_ID_g   = H5I_INVALID_HID;
 hid_t H5P_LST_DATASET_XFER_ID_g     = H5I_INVALID_HID;
 hid_t H5P_LST_DATATYPE_ACCESS_ID_g  = H5I_INVALID_HID;
 hid_t H5P_LST_DATATYPE_CREATE_ID_g  = H5I_INVALID_HID;
-hid_t H5P_LST_FILE_ACCESS_ANY_VFD_g = H5I_INVALID_HID;
 hid_t H5P_LST_FILE_ACCESS_ID_g      = H5I_INVALID_HID;
 hid_t H5P_LST_FILE_CREATE_ID_g      = H5I_INVALID_HID;
 hid_t H5P_LST_FILE_MOUNT_ID_g       = H5I_INVALID_HID;
@@ -605,7 +604,6 @@ H5P_term_package(void)
                 H5P_LST_DATASET_XFER_ID_g     = H5I_INVALID_HID;
                 H5P_LST_DATATYPE_ACCESS_ID_g  = H5I_INVALID_HID;
                 H5P_LST_DATATYPE_CREATE_ID_g  = H5I_INVALID_HID;
-                H5P_LST_FILE_ACCESS_ANY_VFD_g = H5I_INVALID_HID;
                 H5P_LST_FILE_ACCESS_ID_g      = H5I_INVALID_HID;
                 H5P_LST_FILE_CREATE_ID_g      = H5I_INVALID_HID;
                 H5P_LST_FILE_MOUNT_ID_g       = H5I_INVALID_HID;
@@ -660,7 +658,6 @@ H5P_term_package(void)
                 H5P_CLS_DATASET_XFER_ID_g     = H5I_INVALID_HID;
                 H5P_CLS_DATATYPE_ACCESS_ID_g  = H5I_INVALID_HID;
                 H5P_CLS_DATATYPE_CREATE_ID_g  = H5I_INVALID_HID;
-                H5P_LST_FILE_ACCESS_ANY_VFD_g = H5I_INVALID_HID;
                 H5P_CLS_FILE_ACCESS_ID_g      = H5I_INVALID_HID;
                 H5P_CLS_FILE_CREATE_ID_g      = H5I_INVALID_HID;
                 H5P_CLS_FILE_MOUNT_ID_g       = H5I_INVALID_HID;
diff --git a/src/H5Ppublic.h b/src/H5Ppublic.h
index ed9db10..4262026 100644
--- a/src/H5Ppublic.h
+++ b/src/H5Ppublic.h
@@ -78,7 +78,6 @@
  */
 #define H5P_FILE_CREATE_DEFAULT      (H5OPEN H5P_LST_FILE_CREATE_ID_g)
 #define H5P_FILE_ACCESS_DEFAULT      (H5OPEN H5P_LST_FILE_ACCESS_ID_g)
-#define H5P_FILE_ACCESS_ANY_VFD      (H5OPEN H5P_LST_FILE_ACCESS_ANY_VFD_g)
 #define H5P_DATASET_CREATE_DEFAULT   (H5OPEN H5P_LST_DATASET_CREATE_ID_g)
 #define H5P_DATASET_ACCESS_DEFAULT   (H5OPEN H5P_LST_DATASET_ACCESS_ID_g)
 #define H5P_DATASET_XFER_DEFAULT     (H5OPEN H5P_LST_DATASET_XFER_ID_g)
@@ -397,7 +396,6 @@ H5_DLLVAR hid_t H5P_CLS_REFERENCE_ACCESS_ID_g;
 /* (Internal to library, do not use!  Use macros above) */
 H5_DLLVAR hid_t H5P_LST_FILE_CREATE_ID_g;
 H5_DLLVAR hid_t H5P_LST_FILE_ACCESS_ID_g;
-H5_DLLVAR hid_t H5P_LST_FILE_ACCESS_ANY_VFD_g;
 H5_DLLVAR hid_t H5P_LST_DATASET_CREATE_ID_g;
 H5_DLLVAR hid_t H5P_LST_DATASET_ACCESS_ID_g;
 H5_DLLVAR hid_t H5P_LST_DATASET_XFER_ID_g;
diff --git a/test/page_buffer.c b/test/page_buffer.c
index c3555aa..9e45809 100644
--- a/test/page_buffer.c
+++ b/test/page_buffer.c
@@ -115,7 +115,9 @@ swmr_fapl_augment(hid_t fapl, const char *filename, uint32_t max_lag)
         HDfprintf(stderr, "H5_basename() failed\n");
         return -1;
     }
-    HDsnprintf(config.md_file_path, sizeof(config.md_file_path), "%s/%s.shadow", dname, bname);
+    HDsnprintf(config.md_file_path, sizeof(config.md_file_path), "%s", dname);
+    HDsnprintf(config.md_file_name, sizeof(config.md_file_name), "%s.shadow", bname);
+
     HDfree(dname);
     HDfree(bname);
 
diff --git a/test/test_vfd_swmr.sh.in b/test/test_vfd_swmr.sh.in
index 08d2706..4548775 100644
--- a/test/test_vfd_swmr.sh.in
+++ b/test/test_vfd_swmr.sh.in
@@ -1095,6 +1095,9 @@ for options in "-d 1" "-d 1 -F" "-d 2 -l 16" "-d 2 -F -l 16" "-d 1 -t" "-d 1 -t
     if [ ${do_many_small:-no} = no ]; then
         continue
     fi
+
+    rm vfd_swmr_bigset*.h5 2> /dev/null
+
     #
     # Test many small datasets of two or three dimensions.
     #
@@ -1188,6 +1191,9 @@ for options in "-d 1" "-d 1 -F" "-d 2 -l 10" "-d 2 -F -l 10" "-d 1 -t -l 10" "-d
     if [ ${do_few_big:-no} = no ]; then
         continue
     fi
+
+    rm vfd_swmr_bigset*.h5 2> /dev/null
+
     echo launch vfd_swmr_bigset_writer few big, options $options ......may take some time......
 
     # Launch the auxiliary process for testing NFS if the --enable-aux-process option is enabled for configuration.
diff --git a/test/vfd_swmr.c b/test/vfd_swmr.c
index e7eb3da..cffe503 100644
--- a/test/vfd_swmr.c
+++ b/test/vfd_swmr.c
@@ -16,8 +16,12 @@
  *
  * Tests the VFD SWMR Feature.
  *
+ * Note: Relevant tests in this file are modified to reflect the
+ *       changes to the fapl for VDS.  See latest RFC.
+ *
  *************************************************************/
 
+#include "H5queue.h"
 #include "h5test.h"
 #include "vfd_swmr_common.h"
 
@@ -103,11 +107,8 @@ static unsigned test_updater_generate_md_checksums(hbool_t file_create);
  *                 --tick_len: should be >= 0
  *                 --max_lag: should be >= 3
  *                 --md_pages_reserved: should be >= 2
- *                 --md_file_path: should contain the metadata file path (POSIX)
  *                 --at least one of maintain_metadata_file and generate_updater_files
  *                   must be true
- *                 --if both the writer and maintain_metadata_file fields are true,
- *                   then md_file_path field shouldn't be empty
  *                 --if both the writer and generate_updater_files fields are true,
  *                   then updater_file_path field shouldn't be empty
  *              B) Verify that info set in the fapl is retrieved correctly.
@@ -182,16 +183,8 @@ test_fapl(void)
 
     /* Set valid md_pages_reserved */
     my_config->md_pages_reserved = 2;
-    /* Should fail: empty md_file_path */
-    H5E_BEGIN_TRY
-    {
-        ret = H5Pset_vfd_swmr_config(fapl, my_config);
-    }
-    H5E_END_TRY;
-    if (ret >= 0)
-        TEST_ERROR;
+    my_config->writer            = TRUE;
 
-    my_config->writer = TRUE;
     /* Should fail: at least one of maintain_metadata_file and generate_updater_files must be true */
     H5E_BEGIN_TRY
     {
@@ -203,16 +196,8 @@ test_fapl(void)
 
     my_config->writer                 = TRUE;
     my_config->maintain_metadata_file = TRUE;
-    /* Should fail: empty md_file_path */
-    H5E_BEGIN_TRY
-    {
-        ret = H5Pset_vfd_swmr_config(fapl, my_config);
-    }
-    H5E_END_TRY;
-    if (ret >= 0)
-        TEST_ERROR;
-
     my_config->generate_updater_files = TRUE;
+
     /* Should fail: empty updater_file_path */
     H5E_BEGIN_TRY
     {
@@ -222,8 +207,8 @@ test_fapl(void)
     if (ret >= 0)
         TEST_ERROR;
 
-    /* Set md_file_path */
-    HDstrcpy(my_config->md_file_path, MD_FILENAME);
+    /* Set md_file_name */
+    HDstrcpy(my_config->md_file_name, MD_FILENAME);
     my_config->generate_updater_files = FALSE;
 
     /* Should succeed in setting the configuration info */
@@ -244,7 +229,9 @@ test_fapl(void)
         TEST_ERROR;
     if (my_config->generate_updater_files)
         TEST_ERROR;
-    if (HDstrcmp(my_config->md_file_path, MD_FILENAME) != 0)
+
+    /* Check md_file_name instead of md_file_path */
+    if (HDstrcmp(my_config->md_file_name, MD_FILENAME) != 0)
         TEST_ERROR;
 
     my_config->generate_updater_files = TRUE;
@@ -269,7 +256,9 @@ test_fapl(void)
         TEST_ERROR;
     if (!my_config->maintain_metadata_file)
         TEST_ERROR;
-    if (HDstrcmp(my_config->md_file_path, MD_FILENAME) != 0)
+
+    /* Check md_file_name instead of md_file_path */
+    if (HDstrcmp(my_config->md_file_name, MD_FILENAME) != 0)
         TEST_ERROR;
 
     /* Close the file access property list */
@@ -348,9 +337,10 @@ test_file_fapl(void)
      * Configured as VFD SWMR reader + no page buffering
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-       flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config1, 4, 7, FALSE, TRUE, FALSE, TRUE, 2, MD_FILENAME, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config1, 4, 7, FALSE, FALSE, TRUE, FALSE, TRUE, 2, NULL, MD_FILENAME, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl1 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 0, config1);
@@ -373,9 +363,10 @@ test_file_fapl(void)
      * Configured as VFD SWMR writer + no page buffering
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-       flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config1, 4, 7, TRUE, TRUE, TRUE, TRUE, 2, MD_FILENAME, UD_FILENAME);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config1, 4, 7, FALSE, TRUE, TRUE, TRUE, TRUE, 2, NULL, MD_FILENAME, UD_FILENAME);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl1 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 0, config1);
@@ -413,9 +404,10 @@ test_file_fapl(void)
      * Configured as VFD SWMR writer + page buffering
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-       flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config1, 4, 7, TRUE, TRUE, FALSE, TRUE, 2, MD_FILENAME, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config1, 4, 7, FALSE, TRUE, TRUE, FALSE, TRUE, 2, NULL, MD_FILENAME, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl1 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config1);
@@ -485,9 +477,10 @@ test_file_fapl(void)
      * Set up different VFD SWMR configuration + page_buffering
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-       flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config2, 4, 10, TRUE, TRUE, FALSE, TRUE, 2, MD_FILENAME, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config2, 4, 10, FALSE, TRUE, TRUE, FALSE, TRUE, 2, NULL, MD_FILENAME, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl2 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config2);
@@ -525,9 +518,10 @@ test_file_fapl(void)
      * Set up as VFD SWMR writer in config1 but different from config2
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-       flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config1, 3, 8, TRUE, TRUE, FALSE, TRUE, 3, MD_FILENAME, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config1, 3, 8, FALSE, TRUE, TRUE, FALSE, TRUE, 3, NULL, MD_FILENAME, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl1 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config1);
@@ -553,7 +547,10 @@ test_file_fapl(void)
      * Set up as VFD SWMR reader in config1 which is same as config2
      */
 
-    init_vfd_swmr_config(config1, 4, 10, TRUE, TRUE, FALSE, TRUE, 2, MD_FILENAME, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config1, 4, 10, FALSE, TRUE, TRUE, FALSE, TRUE, 2, NULL, MD_FILENAME, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl1 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config1);
@@ -691,9 +688,10 @@ test_file_end_tick(void)
      * Configured file 1 as VFD SWMR writer + page buffering
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-       flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config1, 10, 15, TRUE, TRUE, FALSE, TRUE, 2, MD_FILENAME, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config1, 10, 15, FALSE, TRUE, TRUE, FALSE, TRUE, 2, NULL, MD_FILENAME, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl1 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config1);
@@ -705,9 +703,10 @@ test_file_end_tick(void)
      * Configured file 2 as VFD SWMR writer + page buffering
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-       flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config2, 5, 6, TRUE, TRUE, FALSE, TRUE, 2, MD_FILENAME2, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config2, 5, 6, FALSE, TRUE, TRUE, FALSE, TRUE, 2, NULL, MD_FILENAME2, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl2 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config2);
@@ -719,9 +718,10 @@ test_file_end_tick(void)
      * Configured file 3 as VFD SWMR writer + page buffering
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-       flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config3, 3, 6, TRUE, TRUE, FALSE, TRUE, 2, MD_FILENAME3, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config3, 3, 6, FALSE, TRUE, TRUE, FALSE, TRUE, 2, NULL, MD_FILENAME3, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl3 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config3);
@@ -896,9 +896,10 @@ test_writer_create_open_flush(void)
      * Set up the VFD SWMR configuration + page buffering
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-       flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(my_config, 1, 3, TRUE, TRUE, FALSE, TRUE, 2, MD_FILENAME, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(my_config, 1, 3, FALSE, TRUE, TRUE, FALSE, TRUE, 2, NULL, MD_FILENAME, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, my_config);
@@ -1017,9 +1018,10 @@ test_writer_md(void)
     if ((my_config = HDmalloc(sizeof(H5F_vfd_swmr_config_t))) == NULL)
         FAIL_STACK_ERROR;
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-       flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(my_config, 1, 3, TRUE, TRUE, FALSE, TRUE, 256, MD_FILENAME, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(my_config, 1, 3, FALSE, TRUE, TRUE, FALSE, TRUE, 256, NULL, MD_FILENAME, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, FS_PAGE_SIZE, my_config);
@@ -1327,9 +1329,10 @@ test_reader_md_concur(void)
      * Set up the VFD SWMR configuration + page buffering
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-       flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config_writer, 1, 3, TRUE, TRUE, FALSE, TRUE, 256, MD_FILENAME, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config_writer, 1, 3, FALSE, TRUE, TRUE, FALSE, TRUE, 256, NULL, MD_FILENAME, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl_writer = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, FS_PAGE_SIZE, config_writer);
@@ -1403,9 +1406,11 @@ test_reader_md_concur(void)
          * Set up the VFD SWMR configuration as reader + page buffering
          */
 
-        /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-        flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-        init_vfd_swmr_config(config_reader, 1, 3, FALSE, TRUE, FALSE, TRUE, 256, MD_FILENAME, NULL);
+        /* config, tick_len, max_lag, presume_posix_semantics, writer,
+         * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+         * md_file_path, md_file_name, updater_file_path */
+        init_vfd_swmr_config(config_reader, 1, 3, FALSE, FALSE, TRUE, FALSE, TRUE, 256, NULL, MD_FILENAME,
+                             NULL);
 
         /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
         fapl_reader = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, FS_PAGE_SIZE, config_reader);
@@ -2010,9 +2015,11 @@ test_multiple_file_opens_concur(void)
 
         /* Set the VFD SWMR configuration in fapl_writer + page buffering */
 
-        /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-        flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-        init_vfd_swmr_config(config_writer, 1, 3, TRUE, TRUE, FALSE, TRUE, 256, MD_FILENAME2, NULL);
+        /* config, tick_len, max_lag, presume_posix_semantics, writer,
+         * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+         * md_file_path, md_file_name, updater_file_path */
+        init_vfd_swmr_config(config_writer, 1, 3, FALSE, TRUE, TRUE, FALSE, TRUE, 256, NULL, MD_FILENAME2,
+                             NULL);
 
         /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
         fapl_writer = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, FS_PAGE_SIZE, config_writer);
@@ -2077,9 +2084,10 @@ test_multiple_file_opens_concur(void)
     if ((config1 = HDmalloc(sizeof(*config1))) == NULL)
         FAIL_STACK_ERROR;
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-    flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config1, 7, 10, TRUE, TRUE, FALSE, TRUE, 256, MD_FILENAME, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config1, 7, 10, FALSE, TRUE, TRUE, FALSE, TRUE, 256, NULL, MD_FILENAME, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl1 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, FS_PAGE_SIZE, config1);
@@ -2120,9 +2128,10 @@ test_multiple_file_opens_concur(void)
     if ((config2 = HDmalloc(sizeof(*config2))) == NULL)
         FAIL_STACK_ERROR;
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-    flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config2, 1, 3, FALSE, TRUE, FALSE, TRUE, 256, MD_FILENAME2, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config2, 1, 3, FALSE, FALSE, TRUE, FALSE, TRUE, 256, NULL, MD_FILENAME2, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl2 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, FS_PAGE_SIZE, config2);
@@ -2259,9 +2268,10 @@ test_disable_enable_eot_concur(void)
      * Set up the VFD SWMR configuration + page buffering
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-    flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config_writer, 1, 3, TRUE, TRUE, FALSE, TRUE, 256, MD_FILENAME, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config_writer, 1, 3, FALSE, TRUE, TRUE, FALSE, TRUE, 256, NULL, MD_FILENAME, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl_writer = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, FS_PAGE_SIZE, config_writer);
@@ -2339,9 +2349,11 @@ test_disable_enable_eot_concur(void)
          * Set up the VFD SWMR configuration as reader + page buffering
          */
 
-        /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-           flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-        init_vfd_swmr_config(config_reader, 1, 3, FALSE, TRUE, FALSE, TRUE, 256, MD_FILENAME, NULL);
+        /* config, tick_len, max_lag, presume_posix_semantics, writer,
+         * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+         * md_file_path, md_file_name, updater_file_path */
+        init_vfd_swmr_config(config_reader, 1, 3, FALSE, FALSE, TRUE, FALSE, TRUE, 256, NULL, MD_FILENAME,
+                             NULL);
 
         /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
         fapl_reader = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, FS_PAGE_SIZE, config_reader);
@@ -2549,9 +2561,10 @@ test_file_end_tick_concur(void)
      * Set up the VFD SWMR configuration + page buffering
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-    flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config_writer, 1, 3, TRUE, TRUE, FALSE, TRUE, 256, MD_FILENAME, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config_writer, 1, 3, FALSE, TRUE, TRUE, FALSE, TRUE, 256, NULL, MD_FILENAME, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl_writer = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, FS_PAGE_SIZE, config_writer);
@@ -2625,9 +2638,11 @@ test_file_end_tick_concur(void)
         if ((config_reader = HDmalloc(sizeof(*config_reader))) == NULL)
             HDexit(EXIT_FAILURE);
 
-        /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-           flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-        init_vfd_swmr_config(config_reader, 1, 3, FALSE, TRUE, FALSE, TRUE, 256, MD_FILENAME, NULL);
+        /* config, tick_len, max_lag, presume_posix_semantics, writer,
+         * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+         * md_file_path, md_file_name, updater_file_path */
+        init_vfd_swmr_config(config_reader, 1, 3, FALSE, FALSE, TRUE, FALSE, TRUE, 256, NULL, MD_FILENAME,
+                             NULL);
 
         /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
         fapl_reader = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, FS_PAGE_SIZE, config_reader);
@@ -2822,18 +2837,20 @@ test_multiple_file_opens(void)
      * Configured as VFD SWMR writer + page buffering
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-    flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config1, 4, 6, TRUE, TRUE, FALSE, TRUE, 2, MD_FILENAME, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config1, 4, 6, FALSE, TRUE, TRUE, FALSE, TRUE, 2, NULL, MD_FILENAME, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl1 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config1);
     if (fapl1 == H5I_INVALID_HID)
         FAIL_STACK_ERROR;
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-    flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config2, 4, 6, TRUE, TRUE, FALSE, TRUE, 2, MD_FILENAME2, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config2, 4, 6, FALSE, TRUE, TRUE, FALSE, TRUE, 2, NULL, MD_FILENAME2, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl2 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config2);
@@ -3033,9 +3050,10 @@ test_same_file_opens(void)
      * Set the VFD SWMR configuration in fapl1 + page buffering
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-    flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config1, 4, 10, TRUE, TRUE, FALSE, TRUE, 2, MD_FILENAME, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config1, 4, 10, FALSE, TRUE, TRUE, FALSE, TRUE, 2, NULL, MD_FILENAME, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl1 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config1);
@@ -3061,9 +3079,10 @@ test_same_file_opens(void)
      * Set the VFD SWMR configuration in fapl2 + page buffering
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-    flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config2, 3, 8, FALSE, TRUE, FALSE, TRUE, 3, MD_FILENAME, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config2, 3, 8, FALSE, FALSE, TRUE, FALSE, TRUE, 3, NULL, MD_FILENAME, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl2 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config2);
@@ -3116,9 +3135,10 @@ test_same_file_opens(void)
      * Set up as VFD SWMR reader + page buffering
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-    flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config1, 4, 10, FALSE, TRUE, FALSE, TRUE, 2, MD_FILENAME, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config1, 4, 10, FALSE, FALSE, TRUE, FALSE, TRUE, 2, NULL, MD_FILENAME, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl1 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config1);
@@ -3153,9 +3173,10 @@ test_same_file_opens(void)
      * Set up as VFD SWMR writer + page buffering
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-    flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config1, 4, 10, TRUE, TRUE, FALSE, TRUE, 2, MD_FILENAME, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config1, 4, 10, FALSE, TRUE, TRUE, FALSE, TRUE, 2, NULL, MD_FILENAME, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl1 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config1);
@@ -3209,9 +3230,10 @@ test_same_file_opens(void)
      * Set up as VFD SWMR writer + page buffering
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-    flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config1, 4, 10, TRUE, TRUE, FALSE, TRUE, 2, MD_FILENAME, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config1, 4, 10, FALSE, TRUE, TRUE, FALSE, TRUE, 2, NULL, MD_FILENAME, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl1 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config1);
@@ -3418,9 +3440,10 @@ test_enable_disable_eot(void)
      * Configured first file as VFD SWMR writer + page buffering
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-    flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config1, 4, 6, TRUE, TRUE, FALSE, TRUE, 2, MD_FILENAME, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config1, 4, 6, FALSE, TRUE, TRUE, FALSE, TRUE, 2, NULL, MD_FILENAME, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl1 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config1);
@@ -3432,9 +3455,10 @@ test_enable_disable_eot(void)
      * Configured second file as VFD SWMR writer + page buffering
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-    flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config2, 4, 6, TRUE, TRUE, FALSE, TRUE, 2, MD_FILENAME2, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config2, 4, 6, FALSE, TRUE, TRUE, FALSE, TRUE, 2, NULL, MD_FILENAME2, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl2 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config2);
@@ -3446,9 +3470,10 @@ test_enable_disable_eot(void)
      * Configured third file as VFD SWMR writer + page buffering
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-    flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config3, 4, 6, TRUE, TRUE, FALSE, TRUE, 2, MD_FILENAME3, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config3, 4, 6, FALSE, TRUE, TRUE, FALSE, TRUE, 2, NULL, MD_FILENAME3, NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl3 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config3);
@@ -3700,6 +3725,7 @@ error:
 static unsigned
 test_updater_flags(void)
 {
+    char  filename[FILE_NAME_LEN];             /* Filename to use */
     hid_t fid       = H5I_INVALID_HID;         /* File ID */
     hid_t fcpl      = H5I_INVALID_HID;         /* File creation property list ID */
     hid_t fapl      = H5I_INVALID_HID;         /* File access property list ID */
@@ -3731,9 +3757,10 @@ test_updater_flags(void)
      * Configured as VFD SWMR writer + page buffering + generate updater files
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-       flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config, 4, 7, TRUE, TRUE, TRUE, TRUE, 2, MD_FILENAME, UD_FILENAME);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config, 4, 7, FALSE, TRUE, TRUE, TRUE, TRUE, 2, NULL, MD_FILENAME, UD_FILENAME);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config);
@@ -3741,12 +3768,15 @@ test_updater_flags(void)
     if (fapl == H5I_INVALID_HID)
         TEST_ERROR;
 
+    /* FILENAME */
+    h5_fixname("vfd_swmr_file", fapl, filename, sizeof(filename));
+
     if ((fcpl = vfd_swmr_create_fcpl(H5F_FSPACE_STRATEGY_PAGE, 4096)) < 0) {
         HDprintf("vfd_swmr_create_fcpl() failed");
         FAIL_STACK_ERROR;
     }
 
-    if ((fid = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl, fapl)) < 0)
+    if ((fid = H5Fcreate(filename, H5F_ACC_TRUNC, fcpl, fapl)) < 0)
         TEST_ERROR;
 
     /* Get the file's file access property list */
@@ -3769,7 +3799,7 @@ test_updater_flags(void)
         TEST_ERROR;
 
     /* Check updater file size */
-    if (HDstat(namebuf, &sb) == 0 && sb.st_size != H5F_UD_HEADER_SIZE)
+    if (HDstat(namebuf, &sb) == 0 && sb.st_size < H5F_UD_HEADER_SIZE)
         TEST_ERROR;
 
     /* Closing */
@@ -3880,9 +3910,10 @@ test_updater_flags_same_file_opens(void)
      * Set the VFD SWMR configuration in fapl1 + page buffering
      */
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-    flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config1, 4, 10, TRUE, TRUE, TRUE, TRUE, 2, MD_FILENAME, UD_FILENAME);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config1, 4, 10, FALSE, TRUE, TRUE, TRUE, TRUE, 2, NULL, MD_FILENAME, UD_FILENAME);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl1 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config1);
@@ -4253,6 +4284,8 @@ test_updater_generate_md_checksums(hbool_t file_create)
     hid_t                   fapl = H5I_INVALID_HID; /* File access property list ID */
     H5F_vfd_swmr_config_t   config;                 /* Configuration for VFD SWMR */
     H5F_generate_md_ck_cb_t cb_info;                /* Callback */
+    H5F_t *                 f = NULL;               /* Internal file object pointer */
+    char *                  md_file_path_name;
 
     if (file_create) {
         TESTING("VFD SWMR updater generate checksums for metadata file with H5Fcreate");
@@ -4261,9 +4294,10 @@ test_updater_generate_md_checksums(hbool_t file_create)
         TESTING("VFD SWMR updater generate checksums for metadata file with H5Fopen");
     }
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-     * flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(&config, 4, 7, TRUE, TRUE, TRUE, TRUE, 2, MD_FILE, UD_FILE);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(&config, 4, 7, FALSE, TRUE, TRUE, TRUE, TRUE, 2, NULL, MD_FILE, UD_FILE);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl = vfd_swmr_create_fapl(TRUE, TRUE, FALSE, 4096, &config);
@@ -4298,6 +4332,13 @@ test_updater_generate_md_checksums(hbool_t file_create)
             FAIL_STACK_ERROR;
     }
 
+    /* Get a pointer to the internal file object */
+    if (NULL == (f = (H5F_t *)H5VL_object(fid)))
+        TEST_ERROR
+
+    /* Get the full metadata file pathname */
+    md_file_path_name = HDstrdup(f->shared->md_file_path_name);
+
     /* Close the file  */
     if (H5Fclose(fid) < 0)
         FAIL_STACK_ERROR;
@@ -4308,11 +4349,11 @@ test_updater_generate_md_checksums(hbool_t file_create)
         FAIL_STACK_ERROR;
 
     /* Verify contents of checksum file and updater files */
-    if (verify_ud_chk(config.md_file_path, config.updater_file_path) < 0)
+    if (verify_ud_chk(md_file_path_name, config.updater_file_path) < 0)
         TEST_ERROR;
 
     /*  It's important to clean up the checksum and updater files. */
-    clean_chk_ud_files(config.md_file_path, config.updater_file_path);
+    clean_chk_ud_files(md_file_path_name, config.updater_file_path);
 
     PASSED();
 
@@ -4328,7 +4369,7 @@ error:
     H5E_END_TRY;
 
     /*  It's important to clean up the chechsum and updater files. */
-    clean_chk_ud_files(config.md_file_path, config.updater_file_path);
+    clean_chk_ud_files(md_file_path_name, config.updater_file_path);
 
     return 1;
 
diff --git a/test/vfd_swmr_addrem_writer.c b/test/vfd_swmr_addrem_writer.c
index 0cd1713..ea395f6 100644
--- a/test/vfd_swmr_addrem_writer.c
+++ b/test/vfd_swmr_addrem_writer.c
@@ -94,9 +94,10 @@ open_skeleton(const char *filename, unsigned verbose)
     if ((config = HDcalloc(1, sizeof(*config))) == NULL)
         goto error;
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-     * flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config, 4, 5, TRUE, TRUE, FALSE, TRUE, 128, "rw-shadow", NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config, 4, 5, FALSE, TRUE, TRUE, FALSE, TRUE, 128, NULL, "rw-shadow", NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     if ((fapl = vfd_swmr_create_fapl(TRUE, TRUE, FALSE, 4096, config)) < 0)
diff --git a/test/vfd_swmr_attrdset_writer.c b/test/vfd_swmr_attrdset_writer.c
index 37c4c72..85ceb01 100644
--- a/test/vfd_swmr_attrdset_writer.c
+++ b/test/vfd_swmr_attrdset_writer.c
@@ -130,40 +130,40 @@ typedef struct {
         .fd_reader_to_writer = -1, .notify = 0, .verify = 0                                                  \
     }
 
-static herr_t state_init(state_t *s, int argc, const char *const *argv);
-
-static herr_t np_init(np_state_t *np, hbool_t writer);
-static herr_t np_close(np_state_t *np, hbool_t writer);
-static herr_t np_writer(hbool_t result, unsigned step, const state_t *s, np_state_t *np,
-                        H5F_vfd_swmr_config_t *config);
-static herr_t np_reader(hbool_t result, unsigned step, const state_t *s, np_state_t *np);
-static herr_t np_confirm_verify_notify(int fd, unsigned step, const state_t *s, np_state_t *np);
-static herr_t np_reader_no_verification(const state_t *s, np_state_t *np, H5F_vfd_swmr_config_t *config);
-
-static herr_t create_dsets(const state_t *s, dsets_state_t *ds);
-static herr_t open_dsets(const state_t *s, dsets_state_t *ds);
-static herr_t open_dset_real(hid_t fid, hid_t *did, const char *name, unsigned *max_compact,
-                             unsigned *min_dense);
-static herr_t close_dsets(const dsets_state_t *ds);
-
-static herr_t perform_dsets_operations(state_t *s, dsets_state_t *ds, H5F_vfd_swmr_config_t *config,
+static hbool_t state_init(state_t *s, int argc, const char *const *argv);
+
+static hbool_t np_init(np_state_t *np, hbool_t writer);
+static hbool_t np_close(np_state_t *np, hbool_t writer);
+static hbool_t np_writer(hbool_t result, unsigned step, const state_t *s, np_state_t *np,
+                         H5F_vfd_swmr_config_t *config);
+static hbool_t np_reader(hbool_t result, unsigned step, const state_t *s, np_state_t *np);
+static hbool_t np_confirm_verify_notify(int fd, unsigned step, const state_t *s, np_state_t *np);
+static hbool_t np_reader_no_verification(const state_t *s, np_state_t *np, H5F_vfd_swmr_config_t *config);
+
+static hbool_t create_dsets(const state_t *s, dsets_state_t *ds);
+static hbool_t open_dsets(const state_t *s, dsets_state_t *ds);
+static hbool_t open_dset_real(hid_t fid, hid_t *did, const char *name, unsigned *max_compact,
+                              unsigned *min_dense);
+static hbool_t close_dsets(const dsets_state_t *ds);
+
+static hbool_t perform_dsets_operations(state_t *s, dsets_state_t *ds, H5F_vfd_swmr_config_t *config,
+                                        np_state_t *np);
+static hbool_t attr_dsets_action(unsigned action, const state_t *s, const dsets_state_t *ds, unsigned which);
+static hbool_t attr_action(unsigned action, const state_t *s, hid_t did, unsigned which);
+static hbool_t add_attr(const state_t *s, hid_t did, unsigned int which);
+static hbool_t modify_attr(const state_t *s, hid_t did, unsigned int which);
+static hbool_t delete_attr(hid_t did, unsigned int which);
+
+static hbool_t verify_dsets_operations(state_t *s, dsets_state_t *ds, H5F_vfd_swmr_config_t *config,
                                        np_state_t *np);
-static herr_t attr_dsets_action(unsigned action, const state_t *s, const dsets_state_t *ds, unsigned which);
-static herr_t attr_action(unsigned action, const state_t *s, hid_t did, unsigned which);
-static herr_t add_attr(const state_t *s, hid_t did, unsigned int which);
-static herr_t modify_attr(const state_t *s, hid_t did, unsigned int which);
-static herr_t delete_attr(hid_t did, unsigned int which);
-
-static herr_t verify_dsets_operations(state_t *s, dsets_state_t *ds, H5F_vfd_swmr_config_t *config,
-                                      np_state_t *np);
-static herr_t verify_attr_dsets_action(unsigned action, const state_t *s, const dsets_state_t *ds,
-                                       unsigned which);
-static herr_t verify_attr_action(unsigned action, hid_t did, unsigned which);
-static herr_t verify_add_or_modify_attr(unsigned action, hid_t did, char *attr_name, unsigned int which);
-static herr_t verify_delete_attr(hid_t did, char *attr_name);
-static herr_t verify_storage_cont(unsigned action, hid_t did, unsigned int which, unsigned max_compact,
-                                  unsigned min_dense, unsigned asteps);
-static herr_t verify_storage_cont_real(hid_t did, unsigned int which, unsigned cut_point);
+static hbool_t verify_attr_dsets_action(unsigned action, const state_t *s, const dsets_state_t *ds,
+                                        unsigned which);
+static hbool_t verify_attr_action(unsigned action, hid_t did, unsigned which);
+static hbool_t verify_add_or_modify_attr(unsigned action, hid_t did, char *attr_name, unsigned int which);
+static hbool_t verify_delete_attr(hid_t did, char *attr_name);
+static hbool_t verify_storage_cont(unsigned action, hid_t did, unsigned int which, unsigned max_compact,
+                                   unsigned min_dense, unsigned asteps);
+static hbool_t verify_storage_cont_real(hid_t did, unsigned int which, unsigned cut_point);
 
 /* Names for datasets */
 #define DSET_COMPACT_NAME  "compact_dset"
@@ -215,7 +215,7 @@ usage(const char *progname)
 /*
  * Initialize option info in state_t
  */
-static herr_t
+static hbool_t
 state_init(state_t *s, int argc, const char *const *argv)
 {
     unsigned long          tmp;
@@ -347,20 +347,20 @@ state_init(state_t *s, int argc, const char *const *argv)
     /* The test file name */
     esnprintf(s->filename, sizeof(s->filename), "vfd_swmr_attrdset.h5");
 
-    return SUCCEED;
+    return true;
 
 error:
     if (tfile)
         HDfree(tfile);
 
-    return FAIL;
+    return false;
 
 } /* state_init() */
 
 /*
  *  Create the datasets as specified on the command line.
  */
-static herr_t
+static hbool_t
 create_dsets(const state_t *s, dsets_state_t *ds)
 {
     hid_t dcpl      = H5I_INVALID_HID;
@@ -719,7 +719,7 @@ create_dsets(const state_t *s, dsets_state_t *ds)
         }
     }
 
-    return SUCCEED;
+    return true;
 
 error:
     H5E_BEGIN_TRY
@@ -741,14 +741,14 @@ error:
     }
     H5E_END_TRY;
 
-    return FAIL;
+    return false;
 
 } /* create_dsets() */
 
 /*
  * Open the datasets as specified.
  */
-static herr_t
+static hbool_t
 open_dsets(const state_t *s, dsets_state_t *ds)
 {
     *ds = DSETS_INITIALIZER;
@@ -796,10 +796,10 @@ open_dsets(const state_t *s, dsets_state_t *ds)
         }
     }
 
-    return SUCCEED;
+    return true;
 
 error:
-    return FAIL;
+    return false;
 
 } /* open_dsets() */
 
@@ -807,7 +807,7 @@ error:
  * Do the real work of opening the dataset.
  * Retrieve the max_compact and min_dense values for the dataset.
  */
-static herr_t
+static hbool_t
 open_dset_real(hid_t fid, hid_t *did, const char *name, unsigned *max_compact, unsigned *min_dense)
 {
     hid_t dcpl = H5I_INVALID_HID;
@@ -832,7 +832,7 @@ open_dset_real(hid_t fid, hid_t *did, const char *name, unsigned *max_compact, u
         TEST_ERROR;
     }
 
-    return SUCCEED;
+    return true;
 
 error:
     H5E_BEGIN_TRY
@@ -842,13 +842,13 @@ error:
     }
     H5E_END_TRY;
 
-    return FAIL;
+    return false;
 } /* open_dset_real() */
 
 /*
  * Close all the datasets as specified.
  */
-static herr_t
+static hbool_t
 close_dsets(const dsets_state_t *ds)
 {
     if (ds->compact_did != H5I_INVALID_HID && H5Dclose(ds->compact_did) < 0) {
@@ -886,7 +886,7 @@ close_dsets(const dsets_state_t *ds)
         TEST_ERROR;
     }
 
-    return SUCCEED;
+    return true;
 
 error:
     H5E_BEGIN_TRY
@@ -901,7 +901,7 @@ error:
     }
     H5E_END_TRY;
 
-    return FAIL;
+    return false;
 } /* close_dsets() */
 
 /*
@@ -914,7 +914,7 @@ error:
  *      MODIFY_ATTR : -m option
  *      DELETE_ATTR : -d <dattrs> option
  */
-static herr_t
+static hbool_t
 perform_dsets_operations(state_t *s, dsets_state_t *ds, H5F_vfd_swmr_config_t *config, np_state_t *np)
 {
     unsigned step;
@@ -974,10 +974,10 @@ perform_dsets_operations(state_t *s, dsets_state_t *ds, H5F_vfd_swmr_config_t *c
         }
     }
 
-    return SUCCEED;
+    return true;
 
 error:
-    return FAIL;
+    return false;
 
 } /* perform_dsets_operations() */
 
@@ -987,7 +987,7 @@ error:
  *      -g: contiguous dataset
  *      -k: 5 chunked datasets with 5 indexing types
  */
-static herr_t
+static hbool_t
 attr_dsets_action(unsigned action, const state_t *s, const dsets_state_t *ds, unsigned which)
 {
     int     nerrors = 0;
@@ -1035,7 +1035,7 @@ attr_dsets_action(unsigned action, const state_t *s, const dsets_state_t *ds, un
     }
 
     if (nerrors)
-        ret = FALSE;
+        ret = false;
 
     return (ret);
 
@@ -1047,7 +1047,7 @@ attr_dsets_action(unsigned action, const state_t *s, const dsets_state_t *ds, un
  *      MODIFY_ATTR : modify `which` attribute
  *      DELETE_ATTR : delete `which` attribute
  */
-static herr_t
+static hbool_t
 attr_action(unsigned action, const state_t *s, hid_t did, unsigned which)
 {
     hbool_t ret;
@@ -1080,7 +1080,7 @@ attr_action(unsigned action, const state_t *s, hid_t did, unsigned which)
  *      H5T_NATIVE_UINT32 (-b) or
  *      H5T_NATIVE_UINT32 (default)
  */
-static herr_t
+static hbool_t
 add_attr(const state_t *s, hid_t did, unsigned int which)
 {
     hid_t aid    = H5I_INVALID_HID;
@@ -1140,7 +1140,7 @@ add_attr(const state_t *s, hid_t did, unsigned int which)
     if (val)
         HDfree(val);
 
-    return SUCCEED;
+    return true;
 
 error:
     H5E_BEGIN_TRY
@@ -1153,14 +1153,14 @@ error:
     if (val)
         HDfree(val);
 
-    return FAIL;
+    return false;
 
 } /* add_attr() */
 
 /*
  * Modify the attribute data.
  */
-static herr_t
+static hbool_t
 modify_attr(const state_t *s, hid_t did, unsigned int which)
 {
     hid_t    aid    = H5I_INVALID_HID;
@@ -1224,7 +1224,7 @@ modify_attr(const state_t *s, hid_t did, unsigned int which)
     if (val)
         HDfree(val);
 
-    return SUCCEED;
+    return true;
 error:
     H5E_BEGIN_TRY
     {
@@ -1236,13 +1236,13 @@ error:
     if (val)
         HDfree(val);
 
-    return FAIL;
+    return false;
 } /* modify_attr() */
 
 /*
  * Delete the attribute
  */
-static herr_t
+static hbool_t
 delete_attr(hid_t did, unsigned int which)
 {
     char name[sizeof("attr-9999999999")];
@@ -1255,10 +1255,10 @@ delete_attr(hid_t did, unsigned int which)
         TEST_ERROR;
     }
 
-    return SUCCEED;
+    return true;
 
 error:
-    return FAIL;
+    return false;
 
 } /* delete_attr() */
 
@@ -1276,7 +1276,7 @@ error:
  *      --[-c <csteps>] is 1
  *      --not applicable for -m option
  */
-static herr_t
+static hbool_t
 verify_dsets_operations(state_t *s, dsets_state_t *ds, H5F_vfd_swmr_config_t *config, np_state_t *np)
 {
     unsigned step;
@@ -1360,11 +1360,11 @@ verify_dsets_operations(state_t *s, dsets_state_t *ds, H5F_vfd_swmr_config_t *co
         }
     }
 
-    return SUCCEED;
+    return true;
 
 error:
 
-    return FAIL;
+    return false;
 } /* verify_dsets_operations() */
 
 /*
@@ -1373,7 +1373,7 @@ error:
  *      -g: contiguous dataset
  *      -k: 5 chunked datasets with 5 indexing types
  */
-static herr_t
+static hbool_t
 verify_attr_dsets_action(unsigned action, const state_t *s, const dsets_state_t *ds, unsigned which)
 {
     int     nerrors = 0;
@@ -1465,7 +1465,7 @@ verify_attr_dsets_action(unsigned action, const state_t *s, const dsets_state_t
 /*
  * Verify the attribute action on the specified dataset.
  */
-static herr_t
+static hbool_t
 verify_attr_action(unsigned action, hid_t did, unsigned which)
 {
     char    name[sizeof("attr-9999999999")];
@@ -1496,7 +1496,7 @@ verify_attr_action(unsigned action, hid_t did, unsigned which)
 /*
  * Verify the attribute is added or modified
  */
-static herr_t
+static hbool_t
 verify_add_or_modify_attr(unsigned action, hid_t did, char *attr_name, unsigned int which)
 {
     unsigned int read_which;
@@ -1575,14 +1575,14 @@ error:
     if (is_vl)
         H5free_memory(read_vl_which);
 
-    return FAIL;
+    return false;
 
 } /* verify_add_or_modify_attr() */
 
 /*
  * Verify the attribute does not exist.
  */
-static herr_t
+static hbool_t
 verify_delete_attr(hid_t did, char *attr_name)
 {
     int ret;
@@ -1592,14 +1592,14 @@ verify_delete_attr(hid_t did, char *attr_name)
         TEST_ERROR;
     }
     else if (!ret) /* attribute does not exist */
-        ret = TRUE;
+        ret = true;
     else /* attribute exist */
-        ret = FALSE;
+        ret = false;
 
     return ret;
 
 error:
-    return FAIL;
+    return false;
 
 } /* verify_delete_attr() */
 
@@ -1617,11 +1617,11 @@ error:
  *          --`which` is at min_dense: dense storage, no continuation block
  *          --`which` is at (min_dense - 1): compact storage, continuation block exists
  */
-static herr_t
+static hbool_t
 verify_storage_cont(unsigned action, hid_t did, unsigned int which, unsigned max_compact, unsigned min_dense,
                     unsigned asteps)
 {
-    hbool_t ret = TRUE;
+    hbool_t ret = true;
 
     HDassert(action == ADD_ATTR || action == DELETE_ATTR);
 
@@ -1660,7 +1660,7 @@ verify_storage_cont(unsigned action, hid_t did, unsigned int which, unsigned max
 /*
  * Verify the storage condition at the specific checkpoint
  */
-static herr_t
+static hbool_t
 verify_storage_cont_real(hid_t did, unsigned int which, unsigned cut_point)
 {
     H5O_native_info_t ninfo;
@@ -1687,7 +1687,7 @@ verify_storage_cont_real(hid_t did, unsigned int which, unsigned cut_point)
     }
 
 error:
-    return FAIL;
+    return false;
 
 } /* verify_storage_cont_real() */
 
@@ -1698,7 +1698,7 @@ error:
 /*
  * Initialize the named pipes for test synchronization.
  */
-static herr_t
+static hbool_t
 np_init(np_state_t *np, hbool_t writer)
 {
     *np = NP_INITIALIZER;
@@ -1746,17 +1746,17 @@ np_init(np_state_t *np, hbool_t writer)
         TEST_ERROR;
     }
 
-    return SUCCEED;
+    return true;
 
 error:
-    return FAIL;
+    return false;
 
 } /* np_init() */
 
 /*
  * Close the named pipes.
  */
-static herr_t
+static hbool_t
 np_close(np_state_t *np, hbool_t writer)
 {
     /* Both the writer and reader close the named pipes */
@@ -1782,16 +1782,16 @@ np_close(np_state_t *np, hbool_t writer)
             TEST_ERROR;
         }
     }
-    return SUCCEED;
+    return true;
 
 error:
-    return FAIL;
+    return false;
 } /* np_close() */
 
 /*
  *  Writer synchronization depending on the result from the attribute action performed.
  */
-static herr_t
+static hbool_t
 np_writer(hbool_t result, unsigned step, const state_t *s, np_state_t *np, H5F_vfd_swmr_config_t *config)
 {
     unsigned int i;
@@ -1841,10 +1841,10 @@ np_writer(hbool_t result, unsigned step, const state_t *s, np_state_t *np, H5F_v
             }
         }
     }
-    return SUCCEED;
+    return true;
 
 error:
-    return FAIL;
+    return false;
 
 } /* np_writer() */
 
@@ -1852,7 +1852,7 @@ error:
  *
  *  Reader synchronization depending on the result from the verification.
  */
-static herr_t
+static hbool_t
 np_reader(hbool_t result, unsigned step, const state_t *s, np_state_t *np)
 {
     /* The verification fails */
@@ -1882,10 +1882,10 @@ np_reader(hbool_t result, unsigned step, const state_t *s, np_state_t *np)
             }
         }
     }
-    return SUCCEED;
+    return true;
 
 error:
-    return FAIL;
+    return false;
 
 } /* np_reader() */
 
@@ -1893,7 +1893,7 @@ error:
  *  Handshake between writer and reader:
  *      Confirm `verify` is same as `notify`.
  */
-static herr_t
+static hbool_t
 np_confirm_verify_notify(int fd, unsigned step, const state_t *s, np_state_t *np)
 {
     if (step % s->csteps == 0) {
@@ -1914,17 +1914,17 @@ np_confirm_verify_notify(int fd, unsigned step, const state_t *s, np_state_t *np
         }
     }
 
-    return SUCCEED;
+    return true;
 
 error:
-    return FAIL;
+    return false;
 } /* confirm_verify_notify() */
 
 /*
  * Synchronization done by the reader before moving onto the
  * next verification phase.
  */
-static herr_t
+static hbool_t
 np_reader_no_verification(const state_t *s, np_state_t *np, H5F_vfd_swmr_config_t *config)
 {
     if (s->use_np) {
@@ -1946,10 +1946,10 @@ np_reader_no_verification(const state_t *s, np_state_t *np, H5F_vfd_swmr_config_
         }
     }
 
-    return SUCCEED;
+    return true;
 
 error:
-    return FAIL;
+    return false;
 
 } /* np_reader_no_verification() */
 
@@ -1981,10 +1981,10 @@ main(int argc, char **argv)
         TEST_ERROR;
     }
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-     * flush_raw_data, md_pages_reserved, md_file_path, updater_file_path
-     */
-    init_vfd_swmr_config(&config, 4, 7, writer, TRUE, FALSE, TRUE, 128, "./attrdset-shadow", NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(&config, 4, 7, FALSE, writer, TRUE, FALSE, TRUE, 128, "./", "attrdset-shadow", NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     if ((fapl = vfd_swmr_create_fapl(TRUE, s.use_vfd_swmr, TRUE, 4096, &config)) < 0) {
diff --git a/test/vfd_swmr_bigset_writer.c b/test/vfd_swmr_bigset_writer.c
index 71bd730..6ff5d03 100644
--- a/test/vfd_swmr_bigset_writer.c
+++ b/test/vfd_swmr_bigset_writer.c
@@ -2580,22 +2580,33 @@ main(int argc, char **argv)
             continue;
         }
 
-        /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-         * flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
+        /* config, tick_len, max_lag, presume_posix_semantics, writer,
+         * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+         * md_file_path, md_file_name, updater_file_path */
+
 #ifdef H5_HAVE_AUX_PROCESS
+
         /* If using the auxiliary process, the writer creates the updater files.
          * The reader uses the metadata file generated by the auxiliary process. */
         if (s.writer) {
-            init_vfd_swmr_config(&config, s.tick_len, s.max_lag, s.writer, FALSE, TRUE, s.flush_raw_data, 128,
-                                 "./bigset-shadow-%zu", "bigset_updater", i);
+            init_vfd_swmr_config(&config, s.tick_len, s.max_lag, FALSE, s.writer, FALSE, TRUE,
+                                 s.flush_raw_data, 128, "./", "bigset-shadow-%zu", "bigset_updater", i);
         }
         else {
-            init_vfd_swmr_config(&config, s.tick_len, s.max_lag, s.writer, TRUE, FALSE, s.flush_raw_data, 128,
-                                 "./mdfile", NULL);
+            init_vfd_swmr_config(&config, s.tick_len, s.max_lag, FALSE, s.writer, TRUE, FALSE,
+                                 s.flush_raw_data, 128, "./", "mdfile", NULL);
         }
 #else
-        init_vfd_swmr_config(&config, s.tick_len, s.max_lag, s.writer, TRUE, FALSE, s.flush_raw_data, 128,
-                             "./bigset-shadow-%zu", NULL, i);
+
+        if (s.vds == vds_multi || s.vds == vds_single) {
+            init_vfd_swmr_config(&config, s.tick_len, s.max_lag, TRUE, s.writer, TRUE, FALSE,
+                                 s.flush_raw_data, 128, "", "", NULL);
+        }
+        else {
+            init_vfd_swmr_config(&config, s.tick_len, s.max_lag, FALSE, s.writer, TRUE, FALSE,
+                                 s.flush_raw_data, 128, "./", "bigset-shadow-%zu", NULL, i);
+        }
+
 #endif
 
         /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
diff --git a/test/vfd_swmr_common.c b/test/vfd_swmr_common.c
index 931b49b..1b87d5f 100644
--- a/test/vfd_swmr_common.c
+++ b/test/vfd_swmr_common.c
@@ -326,15 +326,14 @@ await_signal(hid_t fid)
 
 #endif /* H5_HAVE_WIN32_API */
 
-/* Revised support routines that can be used for all VFD SWMR integration tests
- * NOTE: For tests that call this common routine, md_file_path needs to be set
- * regardless of whether maintain_metadata_file is true or false.
+/*
+ * Revised support routines that can be used for all VFD SWMR integration tests
  */
 void
-init_vfd_swmr_config(H5F_vfd_swmr_config_t *config, uint32_t tick_len, uint32_t max_lag, hbool_t writer,
-                     hbool_t maintain_metadata_file, hbool_t generate_updater_files, hbool_t flush_raw_data,
-                     uint32_t md_pages_reserved, const char *md_file_fmtstr, const char *updater_file_path,
-                     ...)
+init_vfd_swmr_config(H5F_vfd_swmr_config_t *config, uint32_t tick_len, uint32_t max_lag,
+                     hbool_t presume_posix_semantics, hbool_t writer, hbool_t maintain_metadata_file,
+                     hbool_t generate_updater_files, hbool_t flush_raw_data, uint32_t md_pages_reserved,
+                     const char *md_file_path, const char *md_file_fmtstr, const char *updater_file_path, ...)
 {
     va_list ap;
 
@@ -343,19 +342,30 @@ init_vfd_swmr_config(H5F_vfd_swmr_config_t *config, uint32_t tick_len, uint32_t
     config->version                = H5F__CURR_VFD_SWMR_CONFIG_VERSION;
     config->pb_expansion_threshold = 0;
 
-    config->tick_len               = tick_len;
-    config->max_lag                = max_lag;
-    config->writer                 = writer;
-    config->maintain_metadata_file = maintain_metadata_file;
-    config->generate_updater_files = generate_updater_files;
-    config->flush_raw_data         = flush_raw_data;
-    config->md_pages_reserved      = md_pages_reserved;
+    config->tick_len                = tick_len;
+    config->max_lag                 = max_lag;
+    config->presume_posix_semantics = presume_posix_semantics;
+    config->writer                  = writer;
+    config->maintain_metadata_file  = maintain_metadata_file;
+    config->generate_updater_files  = generate_updater_files;
+    config->flush_raw_data          = flush_raw_data;
+    config->md_pages_reserved       = md_pages_reserved;
+
+    if (md_file_path == NULL)
+        config->md_file_path[0] = '\0';
+    else
+        HDstrcpy(config->md_file_path, md_file_path);
 
-    HDva_start(ap, updater_file_path);
+    if (md_file_fmtstr == NULL)
+        config->md_file_name[0] = '\0';
 
-    evsnprintf(config->md_file_path, sizeof(config->md_file_path), md_file_fmtstr, ap);
+    else {
+        HDva_start(ap, updater_file_path);
 
-    HDva_end(ap);
+        evsnprintf(config->md_file_name, sizeof(config->md_file_path), md_file_fmtstr, ap);
+
+        HDva_end(ap);
+    }
 
     if (config->generate_updater_files && updater_file_path != NULL)
         HDstrcpy(config->updater_file_path, updater_file_path);
diff --git a/test/vfd_swmr_common.h b/test/vfd_swmr_common.h
index 4fd45b4..8d6f2d5 100644
--- a/test/vfd_swmr_common.h
+++ b/test/vfd_swmr_common.h
@@ -74,10 +74,11 @@ H5TEST_DLL hid_t vfd_swmr_create_fapl(bool use_latest_format, bool use_vfd_swmr,
                                       size_t page_buf_size, H5F_vfd_swmr_config_t *config);
 
 H5TEST_DLL void init_vfd_swmr_config(H5F_vfd_swmr_config_t *config, uint32_t tick_len, uint32_t max_lag,
-                                     hbool_t writer, hbool_t maintain_metadata_file,
-                                     hbool_t generate_updater_files, hbool_t flush_raw_data,
-                                     uint32_t md_pages_reserved, const char *md_file_fmtstr,
-                                     const char *updater_file_path, ...) H5_ATTR_FORMAT(printf, 9, 11);
+                                     hbool_t presume_posix_semantics, hbool_t writer,
+                                     hbool_t maintain_metadata_file, hbool_t generate_updater_files,
+                                     hbool_t flush_raw_data, uint32_t md_pages_reserved,
+                                     const char *md_file_path, const char *md_file_fmtstr,
+                                     const char *updater_file_path, ...) H5_ATTR_FORMAT(printf, 11, 13);
 
 H5TEST_DLL void init_vfd_swmr_log(H5F_vfd_swmr_config_t *config, const char *log_file_fmtstr, ...)
     H5_ATTR_FORMAT(printf, 2, 3);
diff --git a/test/vfd_swmr_dsetchks_writer.c b/test/vfd_swmr_dsetchks_writer.c
index caaad1b..1e4de5a 100644
--- a/test/vfd_swmr_dsetchks_writer.c
+++ b/test/vfd_swmr_dsetchks_writer.c
@@ -2308,10 +2308,11 @@ main(int argc, char **argv)
         TEST_ERROR;
     }
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-     * flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(&config, 4, 7, writer, TRUE, FALSE, s.flush_raw_data, 128, "./dsetchks-shadow",
-                         NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(&config, 4, 7, FALSE, writer, TRUE, FALSE, s.flush_raw_data, 128, "./",
+                         "dsetchks-shadow", NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     if ((fapl = vfd_swmr_create_fapl(true, s.use_vfd_swmr, true, 4096, &config)) < 0) {
diff --git a/test/vfd_swmr_dsetops_writer.c b/test/vfd_swmr_dsetops_writer.c
index 8ef0962..cdb84b2 100644
--- a/test/vfd_swmr_dsetops_writer.c
+++ b/test/vfd_swmr_dsetops_writer.c
@@ -2228,9 +2228,11 @@ main(int argc, char **argv)
         TEST_ERROR;
     }
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-     * flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(&config, 4, 7, writer, TRUE, FALSE, s.flush_raw_data, 128, "./dsetops-shadow", NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(&config, 4, 7, FALSE, writer, TRUE, FALSE, s.flush_raw_data, 128, "./",
+                         "dsetops-shadow", NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     if ((fapl = vfd_swmr_create_fapl(true, s.use_vfd_swmr, true, 4096, &config)) < 0) {
diff --git a/test/vfd_swmr_generator.c b/test/vfd_swmr_generator.c
index a78abbc..1392293 100644
--- a/test/vfd_swmr_generator.c
+++ b/test/vfd_swmr_generator.c
@@ -125,9 +125,11 @@ gen_skeleton(const char *filename, hbool_t verbose, hbool_t vfd_swmr_write, int
         if ((config = HDcalloc(1, sizeof(*config))) == NULL)
             return -1;
 
-        /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-         * flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-        init_vfd_swmr_config(config, 4, 10, vfd_swmr_write, TRUE, FALSE, TRUE, 128, "generator-shadow", NULL);
+        /* config, tick_len, max_lag, presume_posix_semantics, writer,
+         * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+         * md_file_path, md_file_name, updater_file_path */
+        init_vfd_swmr_config(config, 4, 10, FALSE, vfd_swmr_write, TRUE, FALSE, TRUE, 128, NULL,
+                             "generator-shadow", NULL);
     }
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
diff --git a/test/vfd_swmr_gfail_writer.c b/test/vfd_swmr_gfail_writer.c
index 27d6c31..10370cc 100644
--- a/test/vfd_swmr_gfail_writer.c
+++ b/test/vfd_swmr_gfail_writer.c
@@ -544,10 +544,11 @@ main(int argc, char **argv)
         TEST_ERROR;
     }
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-     * flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(&config, s.tick_len, s.max_lag, writer, TRUE, FALSE, TRUE, 128, "./group-shadow",
-                         NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(&config, s.tick_len, s.max_lag, FALSE, writer, TRUE, FALSE, TRUE, 128, "./",
+                         "group-shadow", NULL);
 
     /* If old-style option is chosen, use the earliest file format(H5F_LIBVER_EARLIEST)
      * as the second parameter of H5Pset_libver_bound() that is called by
diff --git a/test/vfd_swmr_gperf_writer.c b/test/vfd_swmr_gperf_writer.c
index 66fd22f..c376b51 100644
--- a/test/vfd_swmr_gperf_writer.c
+++ b/test/vfd_swmr_gperf_writer.c
@@ -2804,10 +2804,11 @@ main(int argc, char **argv)
         return EXIT_SUCCESS;
     }
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-     * flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(&config, s.tick_len, s.max_lag, writer, TRUE, FALSE, FALSE, 128, "./group-shadow",
-                         NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(&config, s.tick_len, s.max_lag, FALSE, writer, TRUE, FALSE, FALSE, 128, "./",
+                         "group-shadow", NULL);
 
     /* If the log flag is on, create the log file log-test under the current directory. */
     if (s.glog == true)
diff --git a/test/vfd_swmr_group_writer.c b/test/vfd_swmr_group_writer.c
index 53c9cec..dd387b2 100644
--- a/test/vfd_swmr_group_writer.c
+++ b/test/vfd_swmr_group_writer.c
@@ -5003,10 +5003,11 @@ main(int argc, char **argv)
         TEST_ERROR;
     }
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-     * flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(&config, s.tick_len, s.max_lag, writer, TRUE, FALSE, TRUE, 128, "./group-shadow",
-                         NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(&config, s.tick_len, s.max_lag, FALSE, writer, TRUE, FALSE, TRUE, 128, "./",
+                         "group-shadow", NULL);
 
     /* If old-style option is chosen, use the earliest file format(H5F_LIBVER_EARLIEST)
      * as the second parameter of H5Pset_libver_bound() that is called by
diff --git a/test/vfd_swmr_indep_rw_writer.c b/test/vfd_swmr_indep_rw_writer.c
index fae4d82..77eee74 100644
--- a/test/vfd_swmr_indep_rw_writer.c
+++ b/test/vfd_swmr_indep_rw_writer.c
@@ -359,14 +359,16 @@ error:
  *  for the VFD SMWR independence of the reader/writer test.
  */
 static hbool_t
-indep_init_vfd_swmr_config_plist(state_t *s, hbool_t writer, const char *mdf_path)
+indep_init_vfd_swmr_config_plist(state_t *s, hbool_t writer, const char *mdf_name)
 {
 
     H5F_vfd_swmr_config_t config;
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-     * flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(&config, s->tick_len, s->max_lag, writer, TRUE, FALSE, TRUE, 128, mdf_path, NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(&config, s->tick_len, s->max_lag, FALSE, writer, TRUE, FALSE, TRUE, 128, "./",
+                         mdf_name, NULL);
 
     /* Pass the use_vfd_swmr, only_meta_page, page buffer size, config to vfd_swmr_create_fapl().*/
     if ((s->fapl = vfd_swmr_create_fapl(TRUE, s->use_vfd_swmr, TRUE, s->pbs, &config)) < 0) {
@@ -645,7 +647,7 @@ main(int argc, char **argv)
     if (s.first_proc) {
 
         writer = TRUE;
-        if (FALSE == indep_init_vfd_swmr_config_plist(&s, writer, "./file1-shadow")) {
+        if (FALSE == indep_init_vfd_swmr_config_plist(&s, writer, "file1-shadow")) {
             HDfprintf(stderr, "Writer: Cannot initialize file property lists for file %s\n", s.filename[0]);
             TEST_ERROR;
         }
@@ -678,7 +680,7 @@ main(int argc, char **argv)
         }
 
         writer = FALSE;
-        if (FALSE == indep_init_vfd_swmr_config_plist(&s, writer, "./file2-shadow")) {
+        if (FALSE == indep_init_vfd_swmr_config_plist(&s, writer, "file2-shadow")) {
             HDfprintf(stderr, "Reader: Cannot initialize file property lists for file %s\n", s.filename[1]);
             TEST_ERROR;
         }
@@ -715,7 +717,7 @@ main(int argc, char **argv)
          * then writes a dataset in the second file for the first process to read.
          */
         writer = FALSE;
-        if (FALSE == indep_init_vfd_swmr_config_plist(&s, writer, "./file1-shadow")) {
+        if (FALSE == indep_init_vfd_swmr_config_plist(&s, writer, "file1-shadow")) {
             HDfprintf(stderr, "Reader: Cannot initialize file property lists for file %s\n", s.filename[0]);
             TEST_ERROR;
         }
@@ -737,7 +739,7 @@ main(int argc, char **argv)
         }
 
         writer = TRUE;
-        if (FALSE == indep_init_vfd_swmr_config_plist(&s, writer, "./file2-shadow")) {
+        if (FALSE == indep_init_vfd_swmr_config_plist(&s, writer, "file2-shadow")) {
             HDfprintf(stderr, "writer: Cannot initialize file property lists for file %s\n", s.filename[1]);
             TEST_ERROR;
         }
diff --git a/test/vfd_swmr_reader.c b/test/vfd_swmr_reader.c
index 153048c..2e918b0 100644
--- a/test/vfd_swmr_reader.c
+++ b/test/vfd_swmr_reader.c
@@ -319,9 +319,10 @@ read_records(const char *filename, hbool_t verbose, FILE *verbose_file, unsigned
         goto error;
     }
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-     * flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config, 4, 5, FALSE, TRUE, FALSE, TRUE, 128, "rw-shadow", NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config, 4, 5, FALSE, FALSE, TRUE, FALSE, TRUE, 128, NULL, "rw-shadow", NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     if ((fapl = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config)) < 0) {
diff --git a/test/vfd_swmr_remove_reader.c b/test/vfd_swmr_remove_reader.c
index 9c684f5..775eb76 100644
--- a/test/vfd_swmr_remove_reader.c
+++ b/test/vfd_swmr_remove_reader.c
@@ -303,9 +303,10 @@ read_records(const char *filename, unsigned verbose, unsigned long nseconds, uns
     if ((config = HDcalloc(1, sizeof(*config))) == NULL)
         goto error;
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-     * flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config, 4, 5, FALSE, TRUE, FALSE, TRUE, 128, "rw-shadow", NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config, 4, 5, FALSE, FALSE, TRUE, FALSE, TRUE, 128, NULL, "rw-shadow", NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     if ((fapl = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config)) < 0) {
diff --git a/test/vfd_swmr_remove_writer.c b/test/vfd_swmr_remove_writer.c
index 1e40a18..72209f8 100644
--- a/test/vfd_swmr_remove_writer.c
+++ b/test/vfd_swmr_remove_writer.c
@@ -86,9 +86,10 @@ open_skeleton(const char *filename, unsigned verbose, unsigned old H5_ATTR_UNUSE
     if ((config = (H5F_vfd_swmr_config_t *)HDcalloc(1, sizeof(H5F_vfd_swmr_config_t))) == NULL)
         goto error;
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-     * flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config, 4, 5, TRUE, TRUE, FALSE, TRUE, 128, "rw-shadow", NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config, 4, 5, FALSE, TRUE, TRUE, FALSE, TRUE, 128, NULL, "rw-shadow", NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     if ((fapl = vfd_swmr_create_fapl(TRUE, TRUE, FALSE, 4096, config)) < 0)
diff --git a/test/vfd_swmr_sparse_reader.c b/test/vfd_swmr_sparse_reader.c
index 1d9557c..2f7856c 100644
--- a/test/vfd_swmr_sparse_reader.c
+++ b/test/vfd_swmr_sparse_reader.c
@@ -207,9 +207,10 @@ read_records(const char *filename, unsigned verbose, unsigned long nrecords, uns
     if ((config = HDcalloc(1, sizeof(H5F_vfd_swmr_config_t))) == NULL)
         goto error;
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-     * flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config, 4, 5, FALSE, TRUE, FALSE, TRUE, 128, "rw-shadow", NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config, 4, 5, FALSE, FALSE, TRUE, FALSE, TRUE, 128, NULL, "rw-shadow", NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     if ((fapl = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config)) < 0) {
diff --git a/test/vfd_swmr_sparse_writer.c b/test/vfd_swmr_sparse_writer.c
index 0d521b7..a233bb3 100644
--- a/test/vfd_swmr_sparse_writer.c
+++ b/test/vfd_swmr_sparse_writer.c
@@ -86,9 +86,10 @@ open_skeleton(const char *filename, unsigned verbose)
     if ((config = (H5F_vfd_swmr_config_t *)HDcalloc(1, sizeof(H5F_vfd_swmr_config_t))) == NULL)
         goto error;
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-     * flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config, 4, 5, TRUE, TRUE, FALSE, TRUE, 128, "rw-shadow", NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config, 4, 5, FALSE, TRUE, TRUE, FALSE, TRUE, 128, NULL, "rw-shadow", NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     if ((fapl = vfd_swmr_create_fapl(TRUE, TRUE, FALSE, 4096, config)) < 0)
diff --git a/test/vfd_swmr_vlstr_reader.c b/test/vfd_swmr_vlstr_reader.c
index cbcc6c0..dc403cf 100644
--- a/test/vfd_swmr_vlstr_reader.c
+++ b/test/vfd_swmr_vlstr_reader.c
@@ -115,9 +115,10 @@ main(int argc, char **argv)
     if (argc > 0)
         errx(EXIT_FAILURE, "unexpected command-line arguments");
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-     * flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(&config, 4, 7, FALSE, TRUE, FALSE, TRUE, 128, "./vlstr-shadow", NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(&config, 4, 7, FALSE, false, TRUE, FALSE, TRUE, 128, "./", "vlstr-shadow", NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl = vfd_swmr_create_fapl(TRUE, use_vfd_swmr, sel == TEST_OOB, 4096, &config);
diff --git a/test/vfd_swmr_vlstr_writer.c b/test/vfd_swmr_vlstr_writer.c
index 682e86a..6a747a2 100644
--- a/test/vfd_swmr_vlstr_writer.c
+++ b/test/vfd_swmr_vlstr_writer.c
@@ -152,10 +152,10 @@ main(int argc, char **argv)
     if (argc > 0)
         errx(EXIT_FAILURE, "unexpected command-line arguments");
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-     * flush_raw_data, md_pages_reserved, md_file_path, updater_file_path
-     */
-    init_vfd_swmr_config(&config, 4, 7, TRUE, TRUE, FALSE, TRUE, 128, "./vlstr-shadow", NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(&config, 4, 7, FALSE, true, TRUE, FALSE, TRUE, 128, "./", "vlstr-shadow", NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     fapl = vfd_swmr_create_fapl(TRUE, use_vfd_swmr, sel == TEST_OOB, 4096, &config);
diff --git a/test/vfd_swmr_writer.c b/test/vfd_swmr_writer.c
index eeceb49..ba9938f 100644
--- a/test/vfd_swmr_writer.c
+++ b/test/vfd_swmr_writer.c
@@ -87,9 +87,10 @@ open_skeleton(const char *filename, hbool_t verbose, FILE *verbose_file, unsigne
     if ((config = (H5F_vfd_swmr_config_t *)HDcalloc(1, sizeof(H5F_vfd_swmr_config_t))) == NULL)
         return -1;
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-     * flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(config, 4, 5, TRUE, TRUE, FALSE, TRUE, 128, "rw-shadow", NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(config, 4, 5, FALSE, TRUE, TRUE, FALSE, TRUE, 128, NULL, "rw-shadow", NULL);
 
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
     if ((fapl = vfd_swmr_create_fapl(TRUE, TRUE, FALSE, 4096, config)) < 0)
diff --git a/test/vfd_swmr_zoo_writer.c b/test/vfd_swmr_zoo_writer.c
index 32726f7..4a6e61c 100644
--- a/test/vfd_swmr_zoo_writer.c
+++ b/test/vfd_swmr_zoo_writer.c
@@ -475,9 +475,11 @@ main(int argc, char **argv)
 
     parse_command_line_options(argc, argv);
 
-    /* config, tick_len, max_lag, writer, maintain_metadata_file, generate_updater_files,
-     * flush_raw_data, md_pages_reserved, md_file_path, updater_file_path */
-    init_vfd_swmr_config(&vfd_swmr_config, TICK_LEN, 7, writer, TRUE, FALSE, TRUE, 128, "./zoo-shadow", NULL);
+    /* config, tick_len, max_lag, presume_posix_semantics, writer,
+     * maintain_metadata_file, generate_updater_files, flush_raw_data, md_pages_reserved,
+     * md_file_path, md_file_name, updater_file_path */
+    init_vfd_swmr_config(&vfd_swmr_config, TICK_LEN, 7, FALSE, writer, TRUE, FALSE, TRUE, 128, "./",
+                         "zoo-shadow", NULL);
 
     /* ? turn off use latest format argument via 1st argument? since later on it reset to early format */
     /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */