1) Core changes for adding NFS/updater support as described in the RFC.

src/H5Pfapl.c
src/H5Fvfd_swmr.c
src/H5Fpublic.h
src/H5Fpkg.h
src/H5Fprivate.h

2) For VFD SWMR testing, add private property for checksum generation of metadata files:
src/H5Fint.c
src/H5Fvfd_swmr.c
src/H5Pfapl.c
src/H5Fpkg.h
src/H5Fprivate.h

3) Fix the following in H5F_vfd_swmr_init() and H5F_vfd_swmr_close_or_flush():
(a) Allocate metadata file index right after metadata file header.
(b) Set tick number to 0 when creating header and index for file open case.
(c) Remove tick number increment at file close.
src/H5Fvfd_swmr.c
src/H5Ftest.c

4) To be consistent with the RFC, change the name for field "chksum" to "checksum" in struct H5FD_vfd_swmr_idx_entry_t:
src/H5FDprivate.h
src/H5FDtest.c
src/H5FDvfd_swmr.c
src/H5Ftest.c
src/H5PB.c

4) Add tests for NFS/updater
test/vfd_swmr.c

5) Modify common routine init_vfd_swmr_config() to accept updater_file_path
test/vfd_swmr_common.c
test/vfd_swmr_common.h

6) Changes to the tests due to the common routine init_vfd_swmr_config():
test/vfd_swmr_addrem_writer.c
test/vfd_swmr_attrdset_writer.c
test/vfd_swmr_bigset_writer.c
test/vfd_swmr_dsetchks_writer.c
test/vfd_swmr_dsetops_writer.c
test/vfd_swmr_generator.c
test/vfd_swmr_gfail_writer.c
test/vfd_swmr_gperf_writer.c
test/vfd_swmr_group_writer.c
test/vfd_swmr_reader.c
test/vfd_swmr_remove_reader.c
test/vfd_swmr_remove_writer.c
test/vfd_swmr_sparse_reader.c
test/vfd_swmr_sparse_writer.c
test/vfd_swmr_vlstr_reader.c
test/vfd_swmr_vlstr_writer.c
test/vfd_swmr_writer.c
test/page_buffer.c

33 files changed, 2147 insertions, 374 deletions

diff --git a/src/H5FDprivate.h b/src/H5FDprivate.h
index 0a8850f..7c0dd77 100644
--- a/src/H5FDprivate.h
+++ b/src/H5FDprivate.h
@@ -168,7 +168,7 @@ typedef struct H5FD_vfd_swmr_idx_entry_t {
     uint64_t hdf5_page_offset;
     uint64_t md_file_page_offset;
     uint32_t length;
-    uint32_t chksum;
+    uint32_t checksum;
     void *   entry_ptr;
     uint64_t tick_of_last_change;
     hbool_t  clean;
diff --git a/src/H5FDtest.c b/src/H5FDtest.c
index a55d34c..521886f 100644
--- a/src/H5FDtest.c
+++ b/src/H5FDtest.c
@@ -162,7 +162,7 @@ H5FD__vfd_swmr_reader_md_test(H5FD_t *file, unsigned num_entries, H5FD_vfd_swmr_
                 HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL,
                             "incorrect md_file_page_offset read from metadata file")
 
-            if (vfd_index[i].chksum != index[i].chksum)
+            if (vfd_index[i].checksum != index[i].checksum)
                 HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "incorrect chksum read from metadata file")
         }
     }
diff --git a/src/H5FDvfd_swmr.c b/src/H5FDvfd_swmr.c
index 568f5d9..73d8df4 100644
--- a/src/H5FDvfd_swmr.c
+++ b/src/H5FDvfd_swmr.c
@@ -857,7 +857,7 @@ H5FD__vfd_swmr_read(H5FD_t *_file, H5FD_mem_t type, hid_t H5_ATTR_UNUSED dxpl_id
      * signature.
      */
     if (file->pb_configured && entry->length == init_size &&
-        H5_checksum_metadata(buf, entry->length, 0) != entry->chksum) {
+        H5_checksum_metadata(buf, entry->length, 0) != entry->checksum) {
         H5FD_vfd_swmr_md_header tmp_header;
 
         if (H5FD__vfd_swmr_header_deserialize(file, &tmp_header) != TRUE)
@@ -1331,7 +1331,7 @@ H5FD__vfd_swmr_index_deserialize(const H5FD_vfd_swmr_t *file, H5FD_vfd_swmr_md_i
             UINT32DECODE(p, md_index->entries[i].hdf5_page_offset);
             UINT32DECODE(p, md_index->entries[i].md_file_page_offset);
             UINT32DECODE(p, md_index->entries[i].length);
-            UINT32DECODE(p, md_index->entries[i].chksum);
+            UINT32DECODE(p, md_index->entries[i].checksum);
         }
     }
     else
diff --git a/src/H5Fint.c b/src/H5Fint.c
index c3fc346..8518785 100644
--- a/src/H5Fint.c
+++ b/src/H5Fint.c
@@ -1853,6 +1853,7 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id)
     hbool_t                ci_write            = FALSE;    /* Whether MDC CI write requested */
     hbool_t                file_create         = FALSE;    /* Creating a new file or not */
     H5F_vfd_swmr_config_t *vfd_swmr_config_ptr = NULL;     /* Points to VFD SMWR config info */
+    H5F_generate_md_ck_cb_t cb_info = {NULL};
     H5F_t *                ret_value           = NULL;     /* Actual return value */
 
     FUNC_ENTER_NOAPI(NULL)
@@ -1876,6 +1877,10 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "file access is writer but VFD SWMR config is reader")
         if ((flags & H5F_ACC_RDWR) == 0 && vfd_swmr_config_ptr->writer)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "file access is reader but VFD SWMR config is writer")
+
+        /* Retrieve the private property for VFD SWMR testing */
+        if (H5P_get(a_plist, H5F_ACS_GENERATE_MD_CK_CB_NAME, &cb_info) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get generate_md_ck_cb info")
     }
 
     /*
@@ -2111,6 +2116,9 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id)
 
         /* Initialization for VFD SWMR writer and reader */
         if (1 == shared->nrefs) {
+            /* Private property for VFD SWMR testing: generate checksum for metadata file */
+            if(cb_info.func)
+                shared->generate_md_ck_cb = cb_info.func;
             if (H5F_vfd_swmr_init(file, file_create) < 0)
                 HGOTO_ERROR(H5E_FILE, H5E_CANTSET, NULL, "file open fail with initialization for VFD SWMR")
         }
diff --git a/src/H5Fpkg.h b/src/H5Fpkg.h
index 706e41d..31630ef 100644
--- a/src/H5Fpkg.h
+++ b/src/H5Fpkg.h
@@ -455,13 +455,36 @@ struct H5F_shared_t {
     uint32_t                   old_mdf_idx_len;
     uint32_t                   old_mdf_idx_entries_used;
 
-    /* Metadata file for VFD SWMR writer */
+    /* Metadata file and updater file for VFD SWMR writer */
     int vfd_swmr_md_fd;      /* POSIX: file descriptor for the
-                              * metadata file
+                              * 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.
+                              */
+    H5F_generate_md_ck_t generate_md_ck_cb;
+                             /* For testing only:
+                              * Invoke the user-defined callback if exists to 
+                              * generate checksum for the metadata file
+                              */
+    
     haddr_t vfd_swmr_md_eoa; /* POSIX: eoa for the metadata
                               * file
                               */
+    uint64_t updater_seq_num;/* Sequence number of the next updater file to be
+                              * genereated.  This field must be initialized to zero,
+                              * and incremented after each updater file is generated.
+                              */
 
     /* Free space manager for the metadata file */
     H5FS_t *       fs_man_md;   /* Free-space manager */
diff --git a/src/H5Fprivate.h b/src/H5Fprivate.h
index cef77dc..05ace44 100644
--- a/src/H5Fprivate.h
+++ b/src/H5Fprivate.h
@@ -647,11 +647,18 @@ uint64_decode(uint8_t **pp)
     {                                                                                                        \
         /* int32_t    version                 = */ 0, /* int32_t    tick_len                = */ 0,          \
             /* int32_t    max_lag                 = */ 0, /* hbool_t    vfd_swmr_writer         = */ FALSE,  \
+            /* hbool_t    maintain_metadata_file         = */ FALSE,                                         \
+            /* hbool_t    generate_updater_files         = */ FALSE,                                         \
             /* hbool_t    flush_raw_data          = */ FALSE, /* int32_t    md_pages_reserved       = */ 0,  \
-            /* int32_t    pb_expansion_threshold  = */ 0, /* char       md_file_path[]          = */ "",     \
+            /* int32_t    pb_expansion_threshold  = */ 0,                                                    \
+            /* char       md_file_path[]          = */ "",                                                   \
+            /* char       updater_file_path[]     = */ "",                                                   \
             /* char       log_file_path[]         = */ ""                                                    \
     }
 
+/*  For VFD SWMR testing only: private property to generate checksum for metadata file via callback */
+#define H5F_ACS_GENERATE_MD_CK_CB_NAME "generate md ck callback"
+
 /* ======================== File Mount properties ====================*/
 #define H5F_MNT_SYM_LOCAL_NAME "local" /* Whether absolute symlinks local to file. */
 
@@ -784,6 +791,72 @@ uint64_decode(uint8_t **pp)
 #define H5SM_TABLE_MAGIC "SMTB" /* Shared Message Table */
 #define H5SM_LIST_MAGIC  "SMLI" /* Shared Message List */
 
+/*
+ * VFD SWMR
+ */
+
+/* Updater file header */
+#define H5F_UD_VERSION      0       /* Version of the updater file format */
+#define H5F_UD_HEADER_OFF   0       /* Updater file header offset */
+#define H5F_UD_HEADER_MAGIC "VUDH"  /* Updater file header magic */
+#define H5F_SIZEOF_CHKSUM   4       /* Size of checksum */
+
+/* Flags in the updater file header */
+#define CREATE_METADATA_FILE_ONLY_FLAG      0x0001
+#define FINAL_UPDATE_FLAG                   0x0002
+
+/* Size of updater file header */
+#define H5F_UD_HEADER_SIZE                                                                                  \
+    (H5_SIZEOF_MAGIC      /* Signature */                                                                   \
+     + 2                  /* Version number */                                                              \
+     + 2                  /* Flags */                                                                       \
+     + 4                  /* Page size */                                                                   \
+     + 8                  /* Sequence number */                                                             \
+     + 8                  /* Tick number */                                                                 \
+     + 8                  /* Chnage list offset */                                                          \
+     + 8                  /* Change list length */                                                          \
+     + H5F_SIZEOF_CHKSUM  /* Updater file header checksum */                                                \
+    )
+
+#define H5F_UD_CL_MAGIC "VUCL"    /* Updater file change list magic */
+
+/* Size of an updater file change list entry */
+#define H5F_UD_CL_ENTRY_SIZE                                                                                \
+    (4                    /* Updater file page offset */                                                    \
+     + 4                  /* Metadata file page offset */                                                   \
+     + 4                  /* HDF5 file page offset */                                                       \
+     + 4                  /* Length */                                                                      \
+     + H5F_SIZEOF_CHKSUM  /* Updater file change list entry checksum */                                     \
+    )
+
+/* Size of updater file change list */
+#define H5F_UD_CL_SIZE(N)         /* N is number of change list entries */                                  \
+    (H5_SIZEOF_MAGIC              /* Signature */                                                           \
+     + 8                          /* Tick num */                                                            \
+     + 4                          /* Metadata file header updater file page offset */                       \
+     + 4                          /* Metadata file header length */                                         \
+     + 4                          /* Metadata file header checksum */                                       \
+     + 4                          /* Metadata file index updater file page offset */                        \
+     + 8                          /* Metadata file index metadata file offset */                            \
+     + 4                          /* Metadata file index length */                                          \
+     + 4                          /* Metadata file index checksum */                                        \
+     + 4                          /* Number of change list entries */                                       \
+     + (N * H5F_UD_CL_ENTRY_SIZE) /* Change list entries */                                                 \
+     + H5F_SIZEOF_CHKSUM          /* Updater file change list checksum */                                   \
+    )
+
+/*  
+ *  For VFD SWMR testing only: 
+ */
+
+/* Callback routine to generate checksum for metadata file specified by md_path */
+typedef herr_t (*H5F_generate_md_ck_t)(char *md_path, uint64_t updater_seq_num);
+
+/* Structure for "generate checksum callback" private property */
+typedef struct H5F_generate_md_ck_cb_t {
+    H5F_generate_md_ck_t    func;
+} H5F_generate_md_ck_cb_t;
+
 /****************************/
 /* Library Private Typedefs */
 /****************************/
@@ -854,6 +927,180 @@ typedef enum H5F_prefix_open_t {
     H5F_PREFIX_EFILE = 2  /* External file prefix   */
 } H5F_prefix_open_t;
 
+/*
+ * VFD SWMR
+ */
+
+/*----------------------------------------------------------------------------
+ *
+ *  struct H5F_vfd_swmr_updater_cl_entry_t
+ *
+ *  An array of instances of H5F_vfd_swmr_updater_cl_entry_t of length equal to
+ *  the number of metadata pages and multi-page metadata entries modified in 
+ *  the past tick is used ot aseemble the assoicated data in preparation for
+ *  writing an updater file.
+ *
+ *  Each entry in this array pertains to a given modified metdata page or
+ *  multi-page metadata entry, and contains the following fields:
+ *
+ *  entry_image_ptr: void pointer to a buffer containing the image of the
+ *      target metadata page or multi-page metadata entry as modified in
+ *      this tick, or NULL if undefined.
+ *
+ *  entry_image_ud_file_page_offset: Page offset of the entry in the
+ *      updater file, or 0 if undefined.
+ *
+ *  entry_image_md_file_page_offset: Page offset of the entry in the 
+ *      metadata file, or 0 if undefined.
+ *
+ *  entry_image_h5_file_page_offset: Page offset of the entry in the
+ *      HDF5 file.  In this case, a page offset of zero is valid,
+ *      so we havd no easy marker for an invalid value.  Instead,
+ *      presume that this field is invalid if the entry_image_md_file_page_offset 
+ *      is invalid.
+ *
+ *  entry_image_len: The size of the metadata page or multi-page metadata
+ *      entry in bytes.
+ *  entry_image_checksum: Checksum of the entry image.
+ *
+ *----------------------------------------------------------------------------
+ */
+typedef struct H5F_vfd_swmr_updater_cl_entry_t {
+    void        *entry_image_ptr;
+    uint32_t    entry_image_ud_file_page_offset;
+    uint32_t    entry_image_md_file_page_offset;
+    uint32_t    entry_image_h5_file_page_offset;
+    size_t      entry_image_len;
+    uint32_t    entry_image_checksum;
+} H5F_vfd_swmr_updater_cl_entry_t;
+
+/*----------------------------------------------------------------------------
+ *
+ *  struct H5F_vfd_swmr_updater_t
+ *
+ *  Instances of this structure are used to assemble the data required to
+ *  write a metadata file updater file.
+ *
+ *  Updater file header related fields:
+ *
+ *  version: Version of the updater file format to be used.  At present this 
+ *          must be zero.
+ *
+ *  flags: This field contains any flags to be set in the updater file header.
+ *      Currently defined flags are:
+ *
+ *              0x0001        CREATE_METADATA_FILE_ONLY_FLAG
+ *      If set, the auxiliary process should create the metadata file, 
+ *      but leave it empty.  This flag may only be set if sequence_num
+ *      is zero.
+ *
+ *              0x0002        FINAL_UPDATE_FLAG
+ *      If set, the VFD SWMR writer is closing the target file, and this 
+ *      updater contains the final set of updates to the metadata file. 
+ *      On receipt, the auxiliary process should apply the enclosed 
+ *      changes to the metadata file, unlink it, and exit.
+ *
+ *  sequence_num: This field contains the sequence number of this updater file.
+ *      The sequence number of the first updater file must be zero, and 
+ *      this sequence number must be increased by one for each new updater
+ *      file.  Note that under some circumstances, the sequence number 
+ *      will not match the tick_num.
+ *
+ *  tick_num: Number of the tick for which this updater file is to be generated.
+ *      This value should match that of the index used to fill our this 
+ *      structure.  
+ *
+ *  header_image_ptr: void pointer to the buffer in which the 
+ *      updater file header is constructed.  
+ *      This field is NULL if the buffer is undefined.
+ *
+ *  header_image_len: This field contains the length of the updater file
+ *      header in bytes.
+ *
+ *  change_list_image_ptr: void pointer to a buffer containing the on disk image
+ *      of the updater file change list, or NULL if that buffer does not exist.
+ *
+ *  change_list_offset: This field contains the offset in bytes of the change 
+ *      list in the updater file.  This will typically be the offset of  
+ *      the first byte in the updater file after the header.
+ *
+ *  change_list_len: This field contains the size in bytes of the on disk image
+ *      of the change list in the updater file.
+ *
+ *  Updater File Change List Related Fields:
+ *
+ *  The updater file change list is a section of the updater file that details the 
+ *  locations and lengths of all metadata file entries that must be modified for 
+ *  this tick.  
+ *
+ *  md_file_header_image_ptr: void pointer to a buffer containing the on disk image
+ *      of the metadata file header as updated for tick_num.
+ *
+ *  md_file_header_ud_file_page_offset: This field contains the updater file 
+ *           page offset of the metadata file header image.  Note that we do 
+ *           not store the metadata file page offset of the metadata file header,
+ *           as it is always written to offset 0 in the metadata file.
+ *
+ *  md_file_header_len: This field contains the size of the metadata file header 
+ *           image in bytes.
+ * 
+ *  md_file_index_image: void pointer to a buffer containing the on disk image
+ *           of the metadata file index as updated for tick_num.
+ *
+ *  md_file_index_md_file_offset: This field contains the offset of the
+ *           metadata file index in the metadata file in bytes.
+ *
+ *           This value will either be the size of the metadata file header
+ *           (if the metadata file header and index are adjacent), or a page 
+ *           aligned value.
+ *
+ *  md_file_index_ud_file_page_offset: This field contains the page offset of the 
+ *           metadata file index in the updater file.
+ *
+ *  md_file_index_len: This field contains the size of the metadata file index in 
+ *           bytes.
+ *
+ *  num_change_list_entries: This field contains the number of entries in the 
+ *           array of H5F_vfd_swmr_updater_cl_ entry_t whose base address
+ *           is stored in the change_list field below.  This value is also the 
+ *           number of metadata pages and multi-page metadata entries that have 
+ *           been modified in the past tick
+ *    
+ *           If this field is zero, there is no change list, and the change_list
+ *           field below is NULL.
+ *
+ *  change_list: This field contains the base address of a dynamically allocated 
+ *          array of H5F_vfd_swmr_updater_cl_entry_t of length num_change_list_entries, 
+ *          or NULL if undefined.
+ *
+ *----------------------------------------------------------------------------
+ */
+typedef struct H5F_vfd_swmr_updater_t {
+    /* Updater file header related fields */
+    uint16_t    version;
+    uint16_t    flags;
+    uint32_t    page_size;
+    uint64_t    sequence_number;
+    uint64_t    tick_num;
+    void        *header_image_ptr;
+    size_t      header_image_len;
+    void        *change_list_image_ptr;
+    uint64_t    change_list_offset;
+    size_t      change_list_len;
+    /* Updater file change list related fields */
+    void        *md_file_header_image_ptr;
+    uint32_t    md_file_header_image_chksum;
+    uint32_t    md_file_header_ud_file_page_offset;
+    size_t      md_file_header_len;
+    void        *md_file_index_image_ptr;
+    uint32_t    md_file_index_image_chksum;
+    uint64_t    md_file_index_md_file_offset;
+    uint32_t    md_file_index_ud_file_page_offset;
+    size_t      md_file_index_len;
+    uint32_t    num_change_list_entries;
+    H5F_vfd_swmr_updater_cl_entry_t *change_list;
+} H5F_vfd_swmr_updater_t;
+
 /*****************************/
 /* Library-private Variables */
 /*****************************/
diff --git a/src/H5Fpublic.h b/src/H5Fpublic.h
index d241816..5e0473a 100644
--- a/src/H5Fpublic.h
+++ b/src/H5Fpublic.h
@@ -275,6 +275,31 @@ typedef herr_t (*H5F_flush_cb_t)(hid_t object_id, void *udata);
  *          A boolean flag indicating whether the file opened with this FAPL entry
  *          will be opened R/W. (i.e. as a VFD SWMR writer)
  *
+ *      maintain_metadata_file
+ *          A boolean flag indicating whether the writer should create and
+ *          maintain the metadata file.  Note that this field is only revelant 
+ *          if the above writer flag is TRUE.
+ *          If this flag is TRUE, the writer must create and maintain the
+ *          metadata file in the location specified in the md_file_path.
+ *          Observe that at least one of maintain_metadata_file and 
+ *          generate_updater_files fields must be TRUE if writer is TRUE.
+ *
+ *      generate_updater_files
+ *          A boolean flag indicating whether the writer should generate a
+ *          sequence of updater files describing how the metadata file
+ *          should be updated at the end of each tick.
+ *          If the flag is TRUE, all modifications to the metadata file 
+ *          (including its creation) are described in an ordered sequence of 
+ *          updater files.  These files are read in order by auxiliary processes, 
+ *          and used to generate local copies of the metadata file as required.
+ *          This mechanism exists to allow VFD SWMR to operate on storage
+ *          systems that do not support POSIX semantics.
+ *          This field is only used by the VFD SWMR writer.  VFD SWMR readers
+ *          ignore this field, as they always look to the specified metadata
+ *          file, regardless of whether it is generated and maintained
+ *          directly by the VFD SWMR writer, or by an auxiliary process that
+ *          polls for new updater files, and applies them as they appear.
+ *
  *      flush_raw_data:
  *          A boolean flag indicating whether raw data should be flushed
  *          as part of the end of tick processing.  If set to TRUE, raw
@@ -307,11 +332,16 @@ typedef herr_t (*H5F_flush_cb_t)(hid_t object_id, void *udata);
  *          of tick is triggered.
  *
  *      md_file_path:
- *          POSIX: this field contains the path of the metadata file.
- *          NFS: it contains the path and base name of the metadata file
- *          updater files.
- *          Object store: it contains the base URL for the objects used
- *          to store metadata file updater objects.
+ *          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.
+ *
+ *      updater_file_path:
+ *          If generate_updater_files is TRUE, the contents of this field depends
+ *          on whether the writer field is TRUE.  If it is, the field contains
+ *          the path and base name of the metadatea file updater files.
+ *          If writer is FALSE, the field is ignored.
  *
  *      log_file_path:
  *          This field contains the path to the log file.  If defined, this path should
@@ -324,10 +354,13 @@ typedef struct H5F_vfd_swmr_config_t {
     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;
     uint32_t pb_expansion_threshold;
     char     md_file_path[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/H5Ftest.c b/src/H5Ftest.c
index b76c579..e9cecc1 100644
--- a/src/H5Ftest.c
+++ b/src/H5Ftest.c
@@ -344,24 +344,10 @@ H5F__vfd_swmr_writer_create_open_flush_test(hid_t file_id, hbool_t file_create)
     /* Verify the minimum size for the metadata file */
     if (HDstat(f->shared->vfd_swmr_config.md_file_path, &stat_buf) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "unable to stat the metadata file")
-    if (stat_buf.st_size <
-        (HDoff_t)((hsize_t)f->shared->vfd_swmr_config.md_pages_reserved * f->shared->fs_page_size))
-        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "incorrect metadata file size")
 
     if (file_create) { /* Creating file */
-        uint32_t hdr_magic;
-
-        /* Seek to the beginning of the file */
-        if (HDlseek(md_fd, (HDoff_t)H5FD_MD_HEADER_OFF, SEEK_SET) < 0)
-            HGOTO_ERROR(H5E_FILE, H5E_SEEKERROR, FAIL, "error seeking metadata file")
-
-        /* Try to read the magic for header */
-        if (HDread(md_fd, &hdr_magic, H5_SIZEOF_MAGIC) < 0)
-            HGOTO_ERROR(H5E_FILE, H5E_READERROR, FAIL, "error reading metadata file")
-
-        /* Verify that there is no header magic in the metadata file */
-        if (HDmemcmp(&hdr_magic, H5FD_MD_HEADER_MAGIC, (size_t)H5_SIZEOF_MAGIC) == 0)
-            HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "error finding header magic in the metadata file")
+        if(stat_buf.st_size != 0)
+            HGOTO_ERROR(H5E_FILE, H5E_READERROR, FAIL, "metadata file should be empty for file create")
     }
     else { /* Opening or flushing the file */
 
@@ -494,7 +480,7 @@ H5F__vfd_swmr_decode_md_idx(int md_fd, H5FD_vfd_swmr_md_header *md_hdr, H5FD_vfd
             UINT32DECODE(p, md_idx->entries[i].hdf5_page_offset);
             UINT32DECODE(p, md_idx->entries[i].md_file_page_offset);
             UINT32DECODE(p, md_idx->entries[i].length);
-            UINT32DECODE(p, md_idx->entries[i].chksum);
+            UINT32DECODE(p, md_idx->entries[i].checksum);
         } /* end for */
 
     } /* end if */
@@ -546,7 +532,7 @@ H5F__vfd_swmr_verify_md_hdr_and_idx(H5F_t *f, H5FD_vfd_swmr_md_header *md_hdr, H
         HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "incorrect index_length read from metadata file")
 
     /* Verify index_offset read from header in the metadata file is the size of md header */
-    if (md_hdr->index_offset != f->shared->fs_page_size)
+    if (md_hdr->index_offset != H5FD_MD_HEADER_SIZE)
         HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "incorrect index_offset read from metadata file")
 
     /* Verify num_entries read from index in the metadata file is num_entries */
@@ -573,8 +559,8 @@ H5F__vfd_swmr_verify_md_hdr_and_idx(H5F_t *f, H5FD_vfd_swmr_md_header *md_hdr, H
                 HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL,
                             "incorrect md_file_page_offset read from metadata file")
 
-            if (md_idx->entries[i].chksum != index[i].chksum)
-                HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "incorrect chksum read from metadata file")
+            if (md_idx->entries[i].checksum != index[i].checksum)
+                HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "incorrect checksum read from metadata file")
         }
     }
 
diff --git a/src/H5Fvfd_swmr.c b/src/H5Fvfd_swmr.c
index 8da238c..fe07e74 100644
--- a/src/H5Fvfd_swmr.c
+++ b/src/H5Fvfd_swmr.c
@@ -25,6 +25,7 @@
 /****************/
 
 #include "H5Fmodule.h" /* This source code file is part of the H5F module */
+#define H5FD_FRIEND     /*suppress error about including H5FDpkg   */
 
 /***********/
 /* Headers */
@@ -36,7 +37,7 @@
 #include "H5Dprivate.h"  /* Datasets                                 */
 #include "H5Eprivate.h"  /* Error handling                           */
 #include "H5Fpkg.h"      /* File access                              */
-#include "H5FDprivate.h" /* File drivers                             */
+#include "H5FDpkg.h"     /* File drivers                             */
 #include "H5Gprivate.h"  /* Groups                                   */
 #include "H5Iprivate.h"  /* IDs                                      */
 #include "H5Lprivate.h"  /* Links                                    */
@@ -97,13 +98,19 @@ const unsigned int log_err_mesg_length = 14;
 /********************/
 
 static herr_t H5F__vfd_swmr_update_end_of_tick_and_tick_num(H5F_shared_t *, hbool_t);
-static herr_t H5F__vfd_swmr_construct_write_md_hdr(H5F_shared_t *, uint32_t);
+static herr_t H5F__vfd_swmr_construct_write_md_hdr(H5F_shared_t *, uint32_t, uint8_t *);
 static herr_t H5F__vfd_swmr_construct_write_md_idx(H5F_shared_t *, uint32_t,
-                                                   struct H5FD_vfd_swmr_idx_entry_t[]);
+                                                   struct H5FD_vfd_swmr_idx_entry_t[], uint8_t *);
 static herr_t H5F__idx_entry_cmp(const void *_entry1, const void *_entry2);
 static herr_t H5F__vfd_swmr_create_index(H5F_shared_t *);
 static herr_t H5F__vfd_swmr_writer__wait_a_tick(H5F_t *);
 
+static herr_t H5F__vfd_swmr_construct_ud_hdr(H5F_vfd_swmr_updater_t *updater);
+static herr_t H5F__vfd_swmr_construct_ud_cl(H5F_vfd_swmr_updater_t *updater);
+static herr_t H5F__generate_updater_file(H5F_t *f, uint32_t num_entries, uint16_t flags,
+    uint8_t *md_file_hdr_image_ptr, size_t md_file_hdr_image_len,
+    uint8_t *md_file_index_image_ptr, uint64_t md_file_index_offset, size_t md_file_index_image_len);
+
 /*********************/
 /* Package Variables */
 /*********************/
@@ -171,9 +178,11 @@ herr_t
 H5F_vfd_swmr_init(H5F_t *f, hbool_t file_create)
 {
     hsize_t       md_size;             /* Size of the metadata file */
-    haddr_t       hdr_addr, idx_addr;  /* Addresses returned from H5MV_alloc() */
-    herr_t        ret_value = SUCCEED; /* Return value */
+    haddr_t       hdr_addr;            /* Address returned from H5MV_alloc() */
     H5F_shared_t *shared    = f->shared;
+    uint8_t md_idx_image[H5FD_MD_INDEX_SIZE(0)];    /* Buffer for metadata file index */
+    uint8_t md_hdr_image[H5FD_MD_HEADER_SIZE];  /* Buffer for metadata file header */
+    herr_t        ret_value = SUCCEED; /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
 
@@ -184,43 +193,26 @@ H5F_vfd_swmr_init(H5F_t *f, hbool_t file_create)
     if (H5F_SHARED_INTENT(shared) & H5F_ACC_RDWR) {
 
         HDassert(shared->vfd_swmr_config.writer);
+        HDassert(shared->vfd_swmr_config.maintain_metadata_file ||
+                 shared->vfd_swmr_config.generate_updater_files);
 
         SIMPLEQ_INIT(&shared->lower_defrees);
         shared->vfd_swmr_writer = TRUE;
-        shared->tick_num        = 1;
-
-        if (H5PB_vfd_swmr__set_tick(shared) < 0)
-            HGOTO_ERROR(H5E_FILE, H5E_SYSTEM, FAIL, "Can't update page buffer current tick")
+        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,
+        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)
             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;
 
-        HDassert(shared->fs_page_size >= H5FD_MD_HEADER_SIZE);
-
-        /* Allocate an entire page from the shadow file for the header. */
-        if ((hdr_addr = H5MV_alloc(f, shared->fs_page_size)) == HADDR_UNDEF) {
+        if ((hdr_addr = H5MV_alloc(f, md_size)) == HADDR_UNDEF) {
             HGOTO_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL, "error allocating shadow-file header");
         }
         HDassert(H5F_addr_eq(hdr_addr, H5FD_MD_HEADER_OFF));
 
-        idx_addr = H5MV_alloc(f, md_size - shared->fs_page_size);
-        if (idx_addr == HADDR_UNDEF) {
-            HGOTO_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL, "error allocating shadow-file index");
-        }
-
-        HDassert(H5F_addr_eq(idx_addr, shared->fs_page_size));
-
-        shared->writer_index_offset = idx_addr;
-
-        /* Set the metadata file size to md_pages_reserved */
-        if (-1 == HDftruncate(shared->vfd_swmr_md_fd, (HDoff_t)md_size))
-            HGOTO_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL, "truncate fail for the metadata file");
-
-        /* Set eof for metadata file to md_pages_reserved */
+        shared->writer_index_offset = H5FD_MD_HEADER_SIZE;
         shared->vfd_swmr_md_eoa = (haddr_t)md_size;
 
         /* When opening an existing HDF5 file, create header and empty
@@ -228,12 +220,34 @@ H5F_vfd_swmr_init(H5F_t *f, hbool_t file_create)
          */
         if (!file_create) {
 
-            if (H5F__vfd_swmr_construct_write_md_idx(shared, 0, NULL) < 0)
+            if (H5F__vfd_swmr_construct_write_md_idx(shared, 0, NULL, md_idx_image) < 0)
                 HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "fail to create index in md");
 
-            if (H5F__vfd_swmr_construct_write_md_hdr(shared, 0) < 0)
+            if (H5F__vfd_swmr_construct_write_md_hdr(shared, 0, md_hdr_image) < 0)
                 HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "fail to create header in md");
+
         }
+
+        /* 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)
+                HGOTO_ERROR(H5E_FILE, H5E_SYSTEM, FAIL, "error from generate_md_ck_cb()")
+        }
+
+        /* Generate updater files if configuration indicates so */
+        if(shared->vfd_swmr_config.generate_updater_files) {
+            shared->updater_seq_num = 0;
+            if(H5F__generate_updater_file(f, 0, file_create ? CREATE_METADATA_FILE_ONLY_FLAG : 0, 
+                                        md_hdr_image, H5FD_MD_HEADER_SIZE,
+                                        md_idx_image, shared->writer_index_offset, H5FD_MD_INDEX_SIZE(0)) < 0)
+                HGOTO_ERROR(H5E_FILE, H5E_SYSTEM, FAIL, "can't generate updater file")
+        }
+
+        shared->tick_num        = 1;
+
+        if (H5PB_vfd_swmr__set_tick(shared) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_SYSTEM, FAIL, "Can't update page buffer current tick")
+
     }
     else { /* VFD SWMR reader  */
 
@@ -254,7 +268,6 @@ H5F_vfd_swmr_init(H5F_t *f, hbool_t file_create)
                                            &(shared->mdf_idx_entries_used), shared->mdf_idx) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_CANTLOAD, FAIL, "unable to load/decode metadata file");
 
-        HDassert(shared->tick_num != 0);
         vfd_swmr_reader_did_increase_tick_to(shared->tick_num);
 
 #if 0  /* JRM */
@@ -310,6 +323,8 @@ H5F_vfd_swmr_close_or_flush(H5F_t *f, hbool_t closing)
 {
     H5F_shared_t *   shared = f->shared;
     shadow_defree_t *curr;
+    uint8_t md_idx_image[H5FD_MD_INDEX_SIZE(0)];    /* Buffer for metadata file index */
+    uint8_t md_hdr_image[H5FD_MD_HEADER_SIZE];  /* Buffer for metadata file header */
     herr_t           ret_value = SUCCEED;
 
     FUNC_ENTER_NOAPI(FAIL)
@@ -318,22 +333,26 @@ H5F_vfd_swmr_close_or_flush(H5F_t *f, hbool_t closing)
     HDassert(shared->vfd_swmr_md_fd >= 0);
 
     /* Write empty index to the md file */
-    if (H5F__vfd_swmr_construct_write_md_idx(shared, 0, NULL) < 0)
+    if (H5F__vfd_swmr_construct_write_md_idx(shared, 0, NULL, md_idx_image) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "fail to create index in md");
 
     /* Write header to the md file */
-    if (H5F__vfd_swmr_construct_write_md_hdr(shared, 0) < 0)
+    if (H5F__vfd_swmr_construct_write_md_hdr(shared, 0, md_hdr_image) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "fail to create header in md");
 
     if (closing) { /* For file close */
 
-        ++shared->tick_num;
-
         /* Close the md file */
         if (HDclose(shared->vfd_swmr_md_fd) < 0)
             HSYS_GOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "unable to close the metadata file");
         shared->vfd_swmr_md_fd = -1;
 
+        /* 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)
+                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)
             HSYS_GOTO_ERROR(H5E_FILE, H5E_CANTREMOVE, FAIL, "unable to unlink the metadata file");
@@ -350,6 +369,13 @@ H5F_vfd_swmr_close_or_flush(H5F_t *f, hbool_t closing)
         }
 
         HDassert(TAILQ_EMPTY(&shared->shadow_defrees));
+
+        if(shared->vfd_swmr_config.generate_updater_files) {
+            if(H5F__generate_updater_file(f, 0, FINAL_UPDATE_FLAG, 
+                                        md_hdr_image, H5FD_MD_HEADER_SIZE,
+                                        md_idx_image, shared->writer_index_offset, H5FD_MD_INDEX_SIZE(0)) < 0)
+                HGOTO_ERROR(H5E_FILE, H5E_SYSTEM, FAIL, "can't generate updater file")
+        }
     }
     else { /* For file flush */
         /* Update end_of_tick */
@@ -438,6 +464,8 @@ H5F_update_vfd_swmr_metadata_file(H5F_t *f, uint32_t num_entries, H5FD_vfd_swmr_
     shadow_defree_t *shadow_defree;
     haddr_t          md_addr;             /* Address in the metadata file */
     uint32_t         i;                   /* Local index variable */
+    uint8_t *md_idx_image = NULL;
+    uint8_t md_hdr_image[H5FD_MD_HEADER_SIZE];  /* Buffer for metadata file header */
     herr_t           ret_value = SUCCEED; /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
@@ -460,13 +488,15 @@ H5F_update_vfd_swmr_metadata_file(H5F_t *f, uint32_t num_entries, H5FD_vfd_swmr_
      *  --Compute checksum, update the index entry, write entry to
      *    the metadata file
      *
-     *  --Set entry_ptr to NULL
+     *  --Set entry_ptr to NULL when not generating updater files
      */
     for (i = 0; i < num_entries; i++) {
 
         if (index[i].entry_ptr == NULL)
             continue;
 
+        HDassert(index[i].tick_of_last_change == f->shared->tick_num);
+
         /* Prepend previous image of the entry to the delayed list */
         if (index[i].md_file_page_offset) {
             if (shadow_image_defer_free(shared, &index[i]) == -1) {
@@ -482,16 +512,16 @@ H5F_update_vfd_swmr_metadata_file(H5F_t *f, uint32_t num_entries, H5FD_vfd_swmr_
 
         /* Compute checksum and update the index entry */
         index[i].md_file_page_offset = md_addr / shared->fs_page_size;
-        index[i].chksum              = H5_checksum_metadata(index[i].entry_ptr, index[i].length, 0);
+        index[i].checksum           = H5_checksum_metadata(index[i].entry_ptr, index[i].length, 0);
 
 #if 0  /* JRM */
         HDfprintf(stderr, 
-   "writing index[%d] fo/mdfo/l/chksum/fc/lc = %lld/%lld/%ld/%lx/%lx/%lx\n",
+   "writing index[%d] fo/mdfo/l/checksum/fc/lc = %lld/%lld/%ld/%lx/%lx/%lx\n",
                 i,
                   index[i].hdf5_page_offset,
                   index[i].md_file_page_offset,
                   index[i].length,
-                  index[i].chksum,
+                  index[i].checksum,
                   (((char*)(index[i].entry_ptr))[0]),
                   (((char*)(index[i].entry_ptr))[4095]));
 
@@ -500,26 +530,34 @@ H5F_update_vfd_swmr_metadata_file(H5F_t *f, uint32_t num_entries, H5FD_vfd_swmr_
         HDassert(shared->fs_page_size == 4096);
 #endif /* JRM */
 
-        /* Seek and write the entry to the metadata file */
-        if (HDlseek(shared->vfd_swmr_md_fd, (HDoff_t)md_addr, SEEK_SET) < 0)
+        if(shared->vfd_swmr_config.maintain_metadata_file) {
 
-            HGOTO_ERROR(H5E_FILE, H5E_SEEKERROR, FAIL, "unable to seek in the metadata file")
+            /* Seek and write the entry to the metadata file */
+            if (HDlseek(shared->vfd_swmr_md_fd, (HDoff_t)md_addr, SEEK_SET) < 0)
 
-        if (HDwrite(shared->vfd_swmr_md_fd, index[i].entry_ptr, index[i].length) != (ssize_t)index[i].length)
+                HGOTO_ERROR(H5E_FILE, H5E_SEEKERROR, FAIL, "unable to seek in the metadata file")
 
-            HGOTO_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL,
-                        "error in writing the page/multi-page entry to metadata file")
+            if (HDwrite(shared->vfd_swmr_md_fd, index[i].entry_ptr, index[i].length) != (ssize_t)index[i].length)
+
+                HGOTO_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL,
+                            "error in writing the page/multi-page entry to metadata file")
+        }
+
+        if(!shared->vfd_swmr_config.generate_updater_files)
+            index[i].entry_ptr = NULL;
 
-        index[i].entry_ptr = NULL;
     }
 
+    if ((md_idx_image = HDmalloc(H5FD_MD_INDEX_SIZE(num_entries))) == NULL)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for md index")
+
     /* Construct and write index to the metadata file */
-    if (H5F__vfd_swmr_construct_write_md_idx(shared, num_entries, index) < 0)
+    if (H5F__vfd_swmr_construct_write_md_idx(shared, num_entries, index, md_idx_image) < 0)
 
         HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "fail to construct & write index to md")
 
     /* Construct and write header to the md file */
-    if (H5F__vfd_swmr_construct_write_md_hdr(shared, num_entries) < 0)
+    if (H5F__vfd_swmr_construct_write_md_hdr(shared, num_entries, md_hdr_image) < 0)
 
         HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "fail to construct & write header to md")
 
@@ -534,26 +572,47 @@ H5F_update_vfd_swmr_metadata_file(H5F_t *f, uint32_t num_entries, H5FD_vfd_swmr_
      *      --remove the associated entries from the list
      */
 
-    if (shared->tick_num <= shared->vfd_swmr_config.max_lag)
-        goto done; // It is too early for any reclamations to be due.
+    /* if (shared->tick_num <= shared->vfd_swmr_config.max_lag), 
+       it is too early for any reclamations to be due.
+     */
+    if (shared->tick_num > shared->vfd_swmr_config.max_lag) {
 
-    TAILQ_FOREACH_REVERSE_SAFE(shadow_defree, &shared->shadow_defrees, shadow_defree_queue, link, prev)
-    {
+        TAILQ_FOREACH_REVERSE_SAFE(shadow_defree, &shared->shadow_defrees, shadow_defree_queue, link, prev)
+        {
 
-        if (shadow_defree->tick_num + shared->vfd_swmr_config.max_lag > shared->tick_num) {
-            break; // No more entries are due for reclamation.
-        }
+            if (shadow_defree->tick_num + shared->vfd_swmr_config.max_lag > shared->tick_num) {
+                break; // No more entries are due for reclamation.
+            }
+
+            if (H5MV_free(f, shadow_defree->offset, shadow_defree->length) < 0) {
+                HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "unable to flush clean entry");
+            }
+
+            TAILQ_REMOVE(&shared->shadow_defrees, shadow_defree, link);
 
-        if (H5MV_free(f, shadow_defree->offset, shadow_defree->length) < 0) {
-            HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "unable to flush clean entry");
+            H5FL_FREE(shadow_defree_t, shadow_defree);
         }
+    }
 
-        TAILQ_REMOVE(&shared->shadow_defrees, shadow_defree, link);
 
-        H5FL_FREE(shadow_defree_t, shadow_defree);
+    /* 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)
+            HGOTO_ERROR(H5E_FILE, H5E_SYSTEM, FAIL, "error from generate_md_ck_cb()")
     }
 
+    /* Generate updater files with num_entries */
+    if(shared->vfd_swmr_config.generate_updater_files)
+        if(H5F__generate_updater_file(f, num_entries, 0, 
+                md_hdr_image, H5FD_MD_HEADER_SIZE,
+                md_idx_image, shared->writer_index_offset, H5FD_MD_INDEX_SIZE(num_entries)) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_SYSTEM, FAIL, "can't generate updater file")
+
 done:
+
+    if (md_idx_image) 
+        HDfree(md_idx_image);
+
     FUNC_LEAVE_NOAPI(ret_value)
 
 } /* end H5F_update_vfd_swmr_metadata_file() */
@@ -1571,9 +1630,8 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F__vfd_swmr_construct_write_md_hdr(H5F_shared_t *shared, uint32_t num_entries)
+H5F__vfd_swmr_construct_write_md_hdr(H5F_shared_t *shared, uint32_t num_entries, uint8_t *image)
 {
-    uint8_t  image[H5FD_MD_HEADER_SIZE]; /* Buffer for header */
     uint8_t *p = NULL;                   /* Pointer to buffer */
     uint32_t metadata_chksum;            /* Computed metadata checksum value */
     /* Size of header and index */
@@ -1607,15 +1665,17 @@ H5F__vfd_swmr_construct_write_md_hdr(H5F_shared_t *shared, uint32_t num_entries)
     /* Sanity checks on header */
     HDassert(p - image == (ptrdiff_t)hdr_size);
 
-    /* Set to beginning of the file */
-    if (HDlseek(shared->vfd_swmr_md_fd, H5FD_MD_HEADER_OFF, SEEK_SET) < 0)
+    if(shared->vfd_swmr_config.maintain_metadata_file) {
+        /* Set to beginning of the file */
+        if (HDlseek(shared->vfd_swmr_md_fd, H5FD_MD_HEADER_OFF, SEEK_SET) < 0)
 
-        HGOTO_ERROR(H5E_VFL, H5E_SEEKERROR, FAIL, "unable to seek in metadata file")
+            HGOTO_ERROR(H5E_VFL, H5E_SEEKERROR, FAIL, "unable to seek in metadata file")
 
-    nwritten = HDwrite(shared->vfd_swmr_md_fd, image, hdr_size);
-    /* Write header to the metadata file */
-    if (nwritten != (ssize_t)hdr_size) {
-        HGOTO_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL, "error in writing header to metadata file")
+        nwritten = HDwrite(shared->vfd_swmr_md_fd, image, hdr_size);
+        /* Write header to the metadata file */
+        if (nwritten != (ssize_t)hdr_size) {
+            HGOTO_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL, "error in writing header to metadata file")
+        }
     }
 
 done:
@@ -1648,9 +1708,8 @@ done:
  */
 static herr_t
 H5F__vfd_swmr_construct_write_md_idx(H5F_shared_t *shared, uint32_t num_entries,
-                                     struct H5FD_vfd_swmr_idx_entry_t index[])
+                                     struct H5FD_vfd_swmr_idx_entry_t index[], uint8_t *image)
 {
-    uint8_t *image = NULL;    /* Pointer to buffer */
     uint8_t *p     = NULL;    /* Pointer to buffer */
     uint32_t metadata_chksum; /* Computed metadata checksum value */
     /* Size of index */
@@ -1663,11 +1722,6 @@ H5F__vfd_swmr_construct_write_md_idx(H5F_shared_t *shared, uint32_t num_entries,
 
     HDassert(num_entries == 0 || index != NULL);
 
-    /* Allocate space for the buffer to hold the index */
-    if ((image = HDmalloc(idx_size)) == NULL)
-
-        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for md index")
-
     /*
      * Encode metadata file index
      */
@@ -1688,7 +1742,7 @@ H5F__vfd_swmr_construct_write_md_idx(H5F_shared_t *shared, uint32_t num_entries,
         UINT32ENCODE(p, index[i].hdf5_page_offset);
         UINT32ENCODE(p, index[i].md_file_page_offset);
         UINT32ENCODE(p, index[i].length);
-        UINT32ENCODE(p, index[i].chksum);
+        UINT32ENCODE(p, index[i].checksum);
     }
 
     /* Calculate checksum for index */
@@ -1703,22 +1757,20 @@ H5F__vfd_swmr_construct_write_md_idx(H5F_shared_t *shared, uint32_t num_entries,
     /* Verify the md file descriptor exists */
     HDassert(shared->vfd_swmr_md_fd >= 0);
 
-    if (HDlseek(shared->vfd_swmr_md_fd, (HDoff_t)shared->writer_index_offset, SEEK_SET) < 0)
-        HGOTO_ERROR(H5E_VFL, H5E_SEEKERROR, FAIL, "unable to seek in metadata file")
+    if(shared->vfd_swmr_config.maintain_metadata_file) {
 
-    nwritten = HDwrite(shared->vfd_swmr_md_fd, image, idx_size);
-    /* Write index to the metadata file */
-    if (nwritten != (ssize_t)idx_size) {
-        HGOTO_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL, "error in writing index to metadata file")
+        if (HDlseek(shared->vfd_swmr_md_fd, (HDoff_t)shared->writer_index_offset, SEEK_SET) < 0)
+            HGOTO_ERROR(H5E_VFL, H5E_SEEKERROR, FAIL, "unable to seek in metadata file")
+
+        nwritten = HDwrite(shared->vfd_swmr_md_fd, image, idx_size);
+        /* Write index to the metadata file */
+        if (nwritten != (ssize_t)idx_size) {
+            HGOTO_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL, "error in writing index to metadata file")
+        }
     }
 
 done:
 
-    if (image) {
-
-        HDfree(image);
-    }
-
     FUNC_LEAVE_NOAPI(ret_value)
 
 } /* H5F__vfd_swmr_construct_write_idx() */
@@ -2010,3 +2062,381 @@ H5F_post_vfd_swmr_log_entry(H5F_t *f, int entry_type_code, char *log_info)
     }
     return;
 }
+
+/*-------------------------------------------------------------------------
+ *
+ * Function:    H5F__vfd_swmr_construct_ud_hdr
+ *
+ * Purpose:     Encode updater header in the buffer updater->header_image_ptr
+ *
+ * Return:      Success:        SUCCEED
+ *              Failure:        FAIL
+ *
+ * Programmer:  Vailin Choi -- 10/2021
+ *
+ * Changes:     None.
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5F__vfd_swmr_construct_ud_hdr(H5F_vfd_swmr_updater_t *updater)
+{
+    uint8_t *p = NULL;                   /* Pointer to buffer */
+    uint8_t     *image = (uint8_t *)updater->header_image_ptr;
+    uint32_t metadata_chksum;            /* Computed metadata checksum value */
+    herr_t       ret_value = SUCCEED; /* Return value */
+
+    FUNC_ENTER_STATIC_NOERR
+
+    /*
+     * Encode metadata file header
+     */
+    p = image;
+
+    /* Encode magic for header */
+    HDmemcpy(p, H5F_UD_HEADER_MAGIC, (size_t)H5_SIZEOF_MAGIC);
+    p += H5_SIZEOF_MAGIC;
+
+    /* Encode version number, flags, page size, sequence number, tick number, change list offset, change list length */
+    UINT16ENCODE(p, H5F_UD_VERSION);
+    UINT16ENCODE(p, updater->flags);
+    UINT32ENCODE(p, updater->page_size);
+    UINT64ENCODE(p, updater->sequence_number);
+    UINT64ENCODE(p, updater->tick_num);
+
+    UINT64ENCODE(p, updater->change_list_offset);
+    UINT64ENCODE(p, updater->change_list_len);
+
+    /* Calculate checksum for header */
+    metadata_chksum = H5_checksum_metadata(image, (size_t)(p - image), 0);
+
+    /* Encode checksum for header */
+    UINT32ENCODE(p, metadata_chksum);
+
+    /* Sanity checks on header */
+    HDassert(p - image == (ptrdiff_t)updater->header_image_len);
+
+    FUNC_LEAVE_NOAPI(ret_value)
+
+} /* H5F__vfd_swmr_construct_ud_hdr() */
+
+/*-------------------------------------------------------------------------
+ *
+ * Function:    H5F__vfd_swmr_construct_ud_cl
+ *
+ * Purpose:     Encode updater change list in the buffer
+ *              updater->change_list_image_ptr
+ *
+ * Return:      Success:        SUCCEED
+ *              Failure:        FAIL
+ *
+ * Programmer:  Vailin Choi -- 10/2021
+ *
+ * Changes:     None.
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5F__vfd_swmr_construct_ud_cl(H5F_vfd_swmr_updater_t *updater)
+{
+    uint8_t *p     = NULL;    /* Pointer to buffer */
+    uint8_t *image = (uint8_t *)updater->change_list_image_ptr;
+    uint32_t metadata_chksum;   /* Computed metadata checksum value */
+    unsigned     i;                   /* Local index variable */
+    herr_t       ret_value = SUCCEED; /* Return value */
+
+    FUNC_ENTER_STATIC_NOERR
+
+    /*
+     * Encode ud cl
+     */
+    p = image;
+
+    /* Encode magic for ud cl */
+    HDmemcpy(p, H5F_UD_CL_MAGIC, H5_SIZEOF_MAGIC);
+    p += H5_SIZEOF_MAGIC;
+
+    /* Encode tick number */
+    UINT64ENCODE(p, updater->tick_num);
+
+    /* Encode Metadata File Header Updater File Page Offset*/
+    UINT32ENCODE(p, updater->md_file_header_ud_file_page_offset);
+
+    /* Encode Metadata File Header Length */
+    UINT32ENCODE(p, updater->md_file_header_len);
+
+    /* Calculate checksum on the image of the metadata file header */
+    updater->md_file_header_image_chksum = H5_checksum_metadata(
+        updater->md_file_header_image_ptr, (size_t)updater->md_file_header_len, 0);
+
+    /* Encode Metadata File Header Checksum */
+    UINT32ENCODE(p, updater->md_file_header_image_chksum);
+
+    /* Encode Metadata File Index Updater File Page Offset*/
+    UINT32ENCODE(p, updater->md_file_index_ud_file_page_offset);
+
+    /* Encode Metadata File Index Metadata File Offset */
+    UINT64ENCODE(p, updater->md_file_index_md_file_offset);
+
+    /* Encode Metadata File Index Length */
+    UINT32ENCODE(p, updater->md_file_index_len);
+
+    /* Calculate checksum on the image of the metadata file index */
+    updater->md_file_index_image_chksum = H5_checksum_metadata(
+        updater->md_file_index_image_ptr, (size_t)updater->md_file_index_len, 0);
+
+    /* Encode Metadata File Index Checksum */
+    UINT32ENCODE(p, updater->md_file_index_image_chksum);
+
+    UINT32ENCODE(p, updater->num_change_list_entries);
+
+    /* Encode the ud cl entries */
+    for (i = 0; i < updater->num_change_list_entries; i++) {
+        UINT32ENCODE(p, updater->change_list[i].entry_image_ud_file_page_offset);
+        UINT32ENCODE(p, updater->change_list[i].entry_image_md_file_page_offset);
+        UINT32ENCODE(p, updater->change_list[i].entry_image_h5_file_page_offset);
+        UINT32ENCODE(p, updater->change_list[i].entry_image_len);
+        UINT32ENCODE(p, updater->change_list[i].entry_image_checksum);
+    }
+
+    /* Calculate checksum for ud cl */
+    metadata_chksum = H5_checksum_metadata(image, (size_t)(p - image), 0);
+
+    /* Encode checksum for index */
+    UINT32ENCODE(p, metadata_chksum);
+
+    /* Sanity checks on index */
+    HDassert(p - image == (ptrdiff_t)updater->change_list_len);
+
+    FUNC_LEAVE_NOAPI(ret_value)
+
+} /* H5F__vfd_swmr_construct_ud_cl() */
+
+/*-------------------------------------------------------------------------
+ *
+ * Function: H5F_generate_updater_file()
+ *
+ * Purpose:  Generate updater file:
+ *              --assemble and initialize data in the updater struct
+ *              --determine num_change_list entries
+ *              --allocate buffers
+ *              --construct on disk image (serialize) of the updater header and change list
+ *              --create updater file using a temporay file name:  
+ *                  --<shared->vfd_swmr_config.updater_file_path>.ud_tmp
+ *              --allocate space and write the following to the updater file
+ *                  --updater file header
+ *                  --updater file change list
+ *                  --metadata entries
+ *                  --metadata file index
+ *                  --metadata file header
+ *              --close the updater file
+ *              --rename the updater file with the correct name:
+ *                  <shared->vfd_swmr_config.updater_file_path>.<shared->updater_seq_num>
+ *
+ *              --increment shared->updater_seq_num
+ *              --free buffers
+ *
+ * Return:   SUCCEED/FAIL
+ *
+ * Programmer: Vailin Choi  8/24/2021
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5F__generate_updater_file(H5F_t *f, uint32_t num_entries, uint16_t flags,
+    uint8_t *md_file_hdr_image_ptr, size_t md_file_hdr_image_len,
+    uint8_t *md_file_index_image_ptr, uint64_t md_file_index_offset,
+    size_t md_file_index_image_len)
+{
+    H5F_shared_t *shared  = f->shared;        /* shared file pointer */
+    H5F_vfd_swmr_updater_t updater;             /* Updater struct */
+    uint32_t next_page_offset;
+    H5FD_t *ud_file      = NULL;        /* Low-level file struct            */
+    char namebuf[H5F__MAX_VFD_SWMR_FILE_NAME_LEN];
+    char newname[H5F__MAX_VFD_SWMR_FILE_NAME_LEN];
+    unsigned i;
+    hsize_t alloc_size;
+    herr_t ret_value = SUCCEED; /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Updater file header fields */
+    updater.version = H5F_UD_VERSION;
+    updater.flags = flags;
+    updater.page_size = (uint32_t)shared->fs_page_size;
+    updater.sequence_number = shared->updater_seq_num;
+    updater.tick_num = shared->tick_num;
+    updater.header_image_ptr = NULL;
+    updater.header_image_len = H5F_UD_HEADER_SIZE;
+    updater.change_list_image_ptr = NULL;
+    updater.change_list_offset = 0;
+    updater.change_list_len = 0;
+
+    /* Updater file change list fields */
+
+    /* md_file_header related fields */
+    updater.md_file_header_ud_file_page_offset = 0;
+    updater.md_file_header_image_ptr = md_file_hdr_image_ptr;   /* parameter */
+    updater.md_file_header_len = md_file_hdr_image_len;         /* parameter */
+    
+    /* md_file_index related fields */
+    updater.md_file_index_ud_file_page_offset = 0;
+    updater.md_file_index_image_ptr = md_file_index_image_ptr;      /* parameter */
+    updater.md_file_index_md_file_offset = md_file_index_offset;    /* parameter */
+    updater.md_file_index_len = md_file_index_image_len;            /* parameter */
+
+    updater.num_change_list_entries = 0;
+    updater.change_list = NULL;
+
+    /* Scan index to determine updater.num_change_list_entries */
+    for (i = 0; i < num_entries; i++) {
+        if (shared->mdf_idx[i].entry_ptr != NULL &&
+            shared->mdf_idx[i].tick_of_last_change == shared->tick_num)
+            updater.num_change_list_entries += 1;
+    }
+
+    if (flags == CREATE_METADATA_FILE_ONLY_FLAG)
+        HDassert(updater.sequence_number == 0);
+        /* For file creation, just generate a header with this flag set */
+    else {
+        /* Update 2 updater file header fields: change_list_len, change_list_offset */
+        updater.change_list_len = H5F_UD_CL_SIZE(updater.num_change_list_entries);
+        updater.change_list_offset = updater.header_image_len;
+    }
+
+
+    /* Create the updater file with a temporary file name */
+    HDsprintf(namebuf, "%s.ud_tmp", shared->vfd_swmr_config.updater_file_path);
+
+    if((ud_file = H5FD_open(namebuf, H5F_ACC_TRUNC|H5F_ACC_RDWR|H5F_ACC_CREAT, H5P_FILE_ACCESS_DEFAULT, HADDR_UNDEF)) == NULL)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "fail to open updater file");
+
+    if ((updater.header_image_ptr = HDmalloc(updater.header_image_len)) == NULL)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for ud header")
+
+    /* Serialize updater file hdr in updater.header_image_ptr */
+    if (H5F__vfd_swmr_construct_ud_hdr(&updater) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "fail to create updater file header ");
+
+    /* Allocate space in updater file for updater file header */
+    if(H5FD__alloc_real(ud_file, H5FD_MEM_DEFAULT, updater.header_image_len, NULL, NULL) == HADDR_UNDEF)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to allocate file memory")
+
+    /* Write updater file header */
+    if(H5FD_write(ud_file, H5FD_MEM_DEFAULT, H5F_UD_HEADER_OFF, updater.header_image_len, updater.header_image_ptr) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL, "ud file write failed")
+
+
+    if (flags != CREATE_METADATA_FILE_ONLY_FLAG) {
+
+        next_page_offset = ((uint32_t)(updater.header_image_len + updater.change_list_len) / updater.page_size) + 1;
+
+        if(updater.num_change_list_entries) {
+
+            /* Allocate space for change list entries */
+            if((updater.change_list = HDmalloc(sizeof(H5F_vfd_swmr_updater_cl_entry_t) * 
+                                               updater.num_change_list_entries)) == NULL)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for ud cl")
+
+
+            /* Initialize change list entries */
+            for (i = 0; i < num_entries; i++) {
+
+                if (shared->mdf_idx[i].entry_ptr != NULL &&
+                    shared->mdf_idx[i].tick_of_last_change == shared->tick_num) {
+
+                    updater.change_list[i].entry_image_ptr = shared->mdf_idx[i].entry_ptr;
+                    updater.change_list[i].entry_image_ud_file_page_offset = 0;
+                    updater.change_list[i].entry_image_md_file_page_offset = (uint32_t)shared->mdf_idx[i].md_file_page_offset;
+                    updater.change_list[i].entry_image_h5_file_page_offset = (uint32_t)shared->mdf_idx[i].hdf5_page_offset;
+                    updater.change_list[i].entry_image_len = shared->mdf_idx[i].length;
+                    updater.change_list[i].entry_image_checksum = shared->mdf_idx[i].checksum;
+
+                    shared->mdf_idx[i].entry_ptr = NULL;
+                }
+            }
+
+            /* Set up page aligned space for all metadata pages */
+            for(i = 0; i < updater.num_change_list_entries; i++) {
+                updater.change_list[i].entry_image_ud_file_page_offset = next_page_offset;
+                next_page_offset += (((uint32_t)updater.change_list[i].entry_image_len / updater.page_size) + 1);
+            }
+        }
+
+        /* Set up page aligned space for the metadata file index */
+        updater.md_file_index_ud_file_page_offset = next_page_offset;
+
+        /* Set up page aligned space for the metadata file header */
+        next_page_offset += (((uint32_t)updater.md_file_index_len / updater.page_size) + 1);
+        updater.md_file_header_ud_file_page_offset = next_page_offset;
+
+        if ((updater.change_list_image_ptr = HDmalloc(updater.change_list_len)) == NULL)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for ud cl ")
+
+        /* Serialize updater file change list in updater.change_list_image_ptr */
+        if (H5F__vfd_swmr_construct_ud_cl(&updater) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "fail to create updater file cl");
+
+        /* Allocate space in updater file for updater file change list */
+        if(H5FD__alloc_real(ud_file, H5FD_MEM_DEFAULT, updater.header_image_len+updater.change_list_len, NULL, NULL) == HADDR_UNDEF)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to allocate file memory")
+
+        /* Write updater file change list */
+        if(H5FD_write(ud_file, H5FD_MEM_DEFAULT, updater.header_image_len, 
+                   updater.change_list_len, updater.change_list_image_ptr) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL, "ud file write failed")
+
+
+        /* Allocate and write metadata pages */
+        for (i = 0; i < updater.num_change_list_entries; i++) {
+            alloc_size = updater.change_list[i].entry_image_ud_file_page_offset * updater.page_size + 
+                         updater.change_list[i].entry_image_len;
+
+            if(H5FD__alloc_real(ud_file, H5FD_MEM_DEFAULT, alloc_size, NULL, NULL) == HADDR_UNDEF)
+                HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to allocate file memory")
+
+            if(H5FD_write(ud_file, H5FD_MEM_DEFAULT, 
+                       updater.change_list[i].entry_image_ud_file_page_offset * updater.page_size,
+                       updater.change_list[i].entry_image_len,
+                       updater.change_list[i].entry_image_ptr) < 0)
+                HGOTO_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL, "ud file write failed")
+        }
+
+        /* Allocate and write metadata file index */
+        alloc_size = updater.md_file_index_ud_file_page_offset * updater.page_size + updater.md_file_index_len;
+        if(H5FD__alloc_real(ud_file, H5FD_MEM_DEFAULT, alloc_size, NULL, NULL) == HADDR_UNDEF)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to allocate file memory")
+
+        if(H5FD_write(ud_file, H5FD_MEM_DEFAULT, updater.md_file_index_ud_file_page_offset * updater.page_size, 
+                   updater.md_file_index_len, updater.md_file_index_image_ptr) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL, "ud file write failed")
+
+        /* Allocate and write metadata file header */
+        alloc_size = updater.md_file_header_ud_file_page_offset * updater.page_size + updater.md_file_header_len;
+        if(H5FD__alloc_real(ud_file, H5FD_MEM_DEFAULT, alloc_size, NULL, NULL) == HADDR_UNDEF)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to allocate file memory")
+
+        if(H5FD_write(ud_file, H5FD_MEM_DEFAULT, updater.md_file_header_ud_file_page_offset * updater.page_size, 
+                updater.md_file_header_len, updater.md_file_header_image_ptr) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL, "ud file write failed")
+    }
+
+    /* Close the updater file and rename the file */
+    if(H5FD_close(ud_file) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "unable to close updater file")
+    HDsprintf(newname, "%s.%lu", shared->vfd_swmr_config.updater_file_path, shared->updater_seq_num);
+    HDrename(namebuf, newname);
+
+    ++shared->updater_seq_num;
+
+done:
+    if(updater.header_image_ptr)
+        HDfree(updater.header_image_ptr);
+    if(updater.change_list_image_ptr)
+        HDfree(updater.change_list_image_ptr);
+    if(updater.change_list)
+        HDfree(updater.change_list);
+
+    FUNC_LEAVE_NOAPI(ret_value)
+
+}  /* H5F__generate_updater_file() */
diff --git a/src/H5PB.c b/src/H5PB.c
index 57ef7fb..ef93bd7 100644
--- a/src/H5PB.c
+++ b/src/H5PB.c
@@ -2121,7 +2121,7 @@ H5PB_vfd_swmr__update_index(H5F_t *f, uint32_t *idx_ent_added_ptr, uint32_t *idx
             /* partial initialization of new entry -- rest done later */
             ie_ptr->hdf5_page_offset    = target_page;
             ie_ptr->md_file_page_offset = 0; /* undefined at this point */
-            ie_ptr->chksum              = 0; /* undefined at this point */
+            ie_ptr->checksum            = 0; /* undefined at this point */
             /* ie_ptr->entry_ptr            initialized below */
             /* ie_ptr->tick_of_last_change  initialized below */
             /* ie_ptr->clean                initialized below */
diff --git a/src/H5Pfapl.c b/src/H5Pfapl.c
index 3b39f12..f833d65 100644
--- a/src/H5Pfapl.c
+++ b/src/H5Pfapl.c
@@ -318,6 +318,16 @@
 #define H5F_ACS_VFD_SWMR_CONFIG_ENC  H5P__facc_vfd_swmr_config_enc
 #define H5F_ACS_VFD_SWMR_CONFIG_DEC  H5P__facc_vfd_swmr_config_dec
 
+/*  Private property for VFD SWMR testing:
+ *      Callback function to generate checksum for metadata file 
+ */
+#define H5F_ACS_GENERATE_MD_CK_CB_SIZE sizeof(H5F_generate_md_ck_cb_t)
+
+#define H5F_ACS_GENERATE_MD_CK_CB_DEF                                       \
+    {                                                                       \
+        NULL                                                                \
+    }
+
 /******************/
 /* Local Typedefs */
 /******************/
@@ -515,6 +525,9 @@ static const hbool_t H5F_def_ignore_disabled_file_locks_g =
     H5F_ACS_IGNORE_DISABLED_FILE_LOCKS_DEF; /* Default ignore disabled file locks flag */
 static const H5F_vfd_swmr_config_t H5F_def_vfd_swmr_config_g =
     H5F_ACS_VFD_SWMR_CONFIG_DEF; /* Default vfd swmr configuration */
+/* For VFD SWMR testing only: Default to generate checksum for metadata file */
+static const H5F_generate_md_ck_t H5F_def_generate_md_ck_cb_g =
+    H5F_ACS_GENERATE_MD_CK_CB_DEF;
 
 /*-------------------------------------------------------------------------
  * Function:    H5P__facc_reg_prop
@@ -633,6 +646,14 @@ H5P__facc_reg_prop(H5P_genclass_t *pclass)
                            NULL) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
 
+    /* Register the private property of whether to generate checksum for metadata file.
+     * It's used for VFD SWMR testing only. */
+    /* (Note: this property should not have an encode/decode callback -QAK) */
+    if (H5P__register_real(pclass, H5F_ACS_GENERATE_MD_CK_CB_NAME, H5F_ACS_GENERATE_MD_CK_CB_SIZE,
+                           &H5F_def_generate_md_ck_cb_g, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
+                           NULL) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
+
     /* Register the data type of multi driver info */
     if (H5P__register_real(pclass, H5F_ACS_MULTI_TYPE_NAME, H5F_ACS_MULTI_TYPE_SIZE, &H5F_def_mem_type_g,
                            NULL, NULL, NULL, H5F_ACS_MULTI_TYPE_ENC, H5F_ACS_MULTI_TYPE_DEC, NULL, NULL, NULL,
@@ -4097,11 +4118,15 @@ H5P__facc_vfd_swmr_config_enc(const void *value, void **_pp, size_t *size)
         INT32ENCODE(*pp, (int32_t)config->tick_len);
         INT32ENCODE(*pp, (int32_t)config->max_lag);
         H5_ENCODE_UNSIGNED(*pp, config->writer);
+        H5_ENCODE_UNSIGNED(*pp, config->maintain_metadata_file);
+        H5_ENCODE_UNSIGNED(*pp, config->generate_updater_files);
         H5_ENCODE_UNSIGNED(*pp, config->flush_raw_data);
         INT32ENCODE(*pp, (int32_t)config->md_pages_reserved);
         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->updater_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->log_file_path),
                  (size_t)(H5F__MAX_VFD_SWMR_FILE_NAME_LEN + 1));
         *pp += H5F__MAX_VFD_SWMR_FILE_NAME_LEN + 1;
@@ -4109,7 +4134,7 @@ H5P__facc_vfd_swmr_config_enc(const void *value, void **_pp, size_t *size)
     } /* end if */
 
     /* Compute encoded size */
-    *size += ((5 * sizeof(int32_t)) + (2 * sizeof(unsigned)) + (2 * (H5F__MAX_VFD_SWMR_FILE_NAME_LEN + 1)));
+    *size += ((5 * sizeof(int32_t)) + (4 * sizeof(unsigned)) + (3 * (H5F__MAX_VFD_SWMR_FILE_NAME_LEN + 1)));
 
     FUNC_LEAVE_NOAPI(SUCCEED)
 } /* end H5P__facc_vfd_swmr_config_enc() */
@@ -4150,6 +4175,8 @@ H5P__facc_vfd_swmr_config_dec(const void **_pp, void *_value)
     UINT32DECODE(*pp, config->max_lag);
 
     H5_DECODE_UNSIGNED(*pp, config->writer);
+    H5_DECODE_UNSIGNED(*pp, config->maintain_metadata_file);
+    H5_DECODE_UNSIGNED(*pp, config->generate_updater_files);
     H5_DECODE_UNSIGNED(*pp, config->flush_raw_data);
 
     /* int */
@@ -4159,6 +4186,9 @@ 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->updater_file_path, (const char *)(*pp));
+    *pp += H5F__MAX_VFD_SWMR_FILE_NAME_LEN + 1;
+
     HDstrcpy(config->log_file_path, (const char *)(*pp));
     *pp += H5F__MAX_VFD_SWMR_FILE_NAME_LEN + 1;
 
@@ -5703,12 +5733,30 @@ H5Pset_vfd_swmr_config(hid_t plist_id, H5F_vfd_swmr_config_t *config_ptr)
     if (config_ptr->pb_expansion_threshold > H5F__MAX_PB_EXPANSION_THRESHOLD)
         HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, FAIL, "pb_expansion_threshold out of range")
 
-    /* Must provide the path for 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")
+    /* If writer is TRUE, at least one of maintain_metadata_file and generate_updater_files must be TRUE */
+    if(config_ptr->writer) {
+        if(!config_ptr->maintain_metadata_file && !config_ptr->generate_updater_files)
+            HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, FAIL, "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")
+    }
+
+    if(config_ptr->writer && config_ptr->generate_updater_files) {
+        /* Must provide the path and base name of the metadata updater files */
+        name_len = HDstrlen(config_ptr->updater_file_path);
+        if (name_len == 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, FAIL, "updater_file_path is empty")
+        else if (name_len > H5F__MAX_VFD_SWMR_FILE_NAME_LEN)
+            HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, FAIL, "updater_file_path is too long")
+    }
+
 
     name_len = HDstrlen(config_ptr->log_file_path);
     if (name_len > H5F__MAX_VFD_SWMR_FILE_NAME_LEN)
diff --git a/test/page_buffer.c b/test/page_buffer.c
index 61e9696..53c9b74 100644
--- a/test/page_buffer.c
+++ b/test/page_buffer.c
@@ -101,6 +101,8 @@ swmr_fapl_augment(hid_t fapl, const char *filename, uint32_t max_lag)
                                     .tick_len          = 4,
                                     .max_lag           = max_lag,
                                     .writer            = true,
+                                    .maintain_metadata_file = true,
+                                    .generate_updater_files = false,
                                     .md_pages_reserved = 128};
     char *                bname  = NULL;
     char *                dname  = NULL;
diff --git a/test/vfd_swmr.c b/test/vfd_swmr.c
index 3ed73c1..e93a399 100644
--- a/test/vfd_swmr.c
+++ b/test/vfd_swmr.c
@@ -41,6 +41,7 @@
 #define FS_PAGE_SIZE 512
 #define FILENAME     "vfd_swmr_file.h5"
 #define MD_FILENAME  "vfd_swmr_metadata_file"
+#define UD_FILENAME  "vfd_swmr_updater_file"
 
 #define FILENAME2    "vfd_swmr_file2.h5"
 #define MD_FILENAME2 "vfd_swmr_metadata_file2"
@@ -48,61 +49,50 @@
 #define FILENAME3    "vfd_swmr_file3.h5"
 #define MD_FILENAME3 "vfd_swmr_metadata_file3"
 
+#define FILENAME4    "vfd_swmr_file4.h5"
+#define MD_FILE      "vfd_swmr_md_file"
+#define UD_FILE      "vfd_swmr_ud_file"
+
 #define FNAME "non_vfd_swmr_file.h5"
 
-/* test routines for VFD SWMR */
-static unsigned test_fapl(void);
-static unsigned test_file_end_tick(void);
-static unsigned test_file_fapl(void);
-static unsigned test_writer_md(void);
+/* Defines used by verify_updater_flags() and verify_ud_chk() helper routine */
 
-/* helper routines */
-static hid_t init_vfd_swmr_config_fapl(H5F_vfd_swmr_config_t *config, uint32_t tick_len, uint32_t max_lag,
-                                       hbool_t is_writer, uint32_t md_pages_reserved,
-                                       const char *md_file_path, size_t pbuf_size);
+/* Offset of "flags" in updater file header */
+#define UD_HD_FLAGS_OFFSET                      6   
 
-/*-------------------------------------------------------------------------
- * Function:    init_vfd_swmr_config_fapl
- *
- * Purpose:     Helper routine to initialize the fields for VFD SWMR configuration
- *
- * Return:      void
- *
- *-------------------------------------------------------------------------
- */
-static hid_t
-init_vfd_swmr_config_fapl(H5F_vfd_swmr_config_t *config, uint32_t tick_len, uint32_t max_lag,
-                          hbool_t is_writer, uint32_t md_pages_reserved, const char *md_file_path,
-                          size_t pbuf_size)
-{
-    hid_t fapl;
+/* Offset of "sequence number" in updater file header */
+#define UD_HD_SEQ_NUM_OFFSET                    12  
 
-    HDmemset(config, 0, sizeof(*config));
+/* Offset of "change list length" in updater file header */
+#define UD_HD_CHANGE_LIST_LEN_OFFSET            36  
 
-    config->version           = H5F__CURR_VFD_SWMR_CONFIG_VERSION;
-    config->tick_len          = tick_len;
-    config->max_lag           = max_lag;
-    config->writer            = is_writer;
-    config->md_pages_reserved = md_pages_reserved;
-    HDstrcpy(config->md_file_path, md_file_path);
+/* Offset of "number of change list entries" in updater file change list header */
+#define UD_CL_NUM_CHANGE_LIST_ENTRIES_OFFSET    H5F_UD_HEADER_SIZE + 44
 
-    /* Create a copy of the file access property list */
-    if ((fapl = H5Pcreate(H5P_FILE_ACCESS)) < 0)
-        return H5I_INVALID_HID;
+/* Size of "sequence number", "tick number" and "change list length" fields in the updater file header */
+#define UD_SIZE_8                                  8
 
-    if (H5Pset_vfd_swmr_config(fapl, config) < 0) {
-        (void)H5Pclose(fapl);
-        return H5I_INVALID_HID;
-    }
+/* Size of checksum and "number of change list entries" field in the updater change list header */
+#define UD_SIZE_4                                  4
 
-    /* Enable page buffering */
-    if (pbuf_size != 0 && H5Pset_page_buffer_size(fapl, pbuf_size, 0, 0) < 0) {
-        (void)H5Pclose(fapl);
-        return H5I_INVALID_HID;
-    }
+/* Size of "flags" field in the updater file header */
+#define UD_SIZE_2                                  2 
+
+/* test routines for VFD SWMR */
+static unsigned test_fapl(void);
+static unsigned test_file_end_tick(void);
+static unsigned test_file_fapl(void);
+static unsigned test_writer_md(void);
+
+static unsigned test_updater_flags(void);
+static unsigned test_updater_flags_same_file_opens(void);
+static herr_t verify_updater_flags(char *ud_name, uint16_t expected_flags);
+
+static void clean_chk_ud_files(char *md_file_path, char *updater_file_path);
+static herr_t verify_ud_chk(char *md_file_path, char *ud_file_path);
+static herr_t md_ck_cb(char *md_file_path, uint64_t tick_num);
+static unsigned test_updater_generate_md_checksums(hbool_t file_create);
 
-    return fapl;
-} /* init_vfd_swmr_config_fapl() */
 
 /*-------------------------------------------------------------------------
  * Function:    test_fapl()
@@ -114,6 +104,12 @@ init_vfd_swmr_config_fapl(H5F_vfd_swmr_config_t *config, uint32_t tick_len, uint
  *                 --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.
  *
  * Return:      0 if test is sucessful
@@ -195,9 +191,40 @@ test_fapl(void)
     if (ret >= 0)
         TEST_ERROR;
 
+    my_config->writer = TRUE;
+    /* Should fail: at least one of maintain_metadata_file and generate_updater_files must be true */
+    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->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
+    {
+        ret = H5Pset_vfd_swmr_config(fapl, my_config);
+    }
+    H5E_END_TRY;
+    if (ret >= 0)
+        TEST_ERROR;
+
     /* Set md_file_path */
     HDstrcpy(my_config->md_file_path, MD_FILENAME);
-    my_config->writer = TRUE;
+    my_config->generate_updater_files = FALSE;
 
     /* Should succeed in setting the configuration info */
     if (H5Pset_vfd_swmr_config(fapl, my_config) < 0)
@@ -215,6 +242,33 @@ test_fapl(void)
         TEST_ERROR;
     if (my_config->md_pages_reserved != 2)
         TEST_ERROR;
+    if (my_config->generate_updater_files)
+        TEST_ERROR;
+    if (HDstrcmp(my_config->md_file_path, MD_FILENAME) != 0)
+        TEST_ERROR;
+
+    my_config->generate_updater_files = TRUE;
+    /* Set updater_file_path */
+    HDstrcpy(my_config->updater_file_path, UD_FILENAME);
+
+    /* Should succeed in setting the configuration info */
+    if (H5Pset_vfd_swmr_config(fapl, my_config) < 0)
+        TEST_ERROR;
+
+    /* Clear the configuration structure */
+    HDmemset(my_config, 0, sizeof(H5F_vfd_swmr_config_t));
+
+    /* Retrieve the configuration info just set */
+    if (H5Pget_vfd_swmr_config(fapl, my_config) < 0)
+        TEST_ERROR;
+
+    /* Verify the configuration info */
+    if (!my_config->generate_updater_files)
+        TEST_ERROR;
+    if (HDstrcmp(my_config->updater_file_path, UD_FILENAME) != 0)
+        TEST_ERROR;
+    if (!my_config->maintain_metadata_file)
+        TEST_ERROR;
     if (HDstrcmp(my_config->md_file_path, MD_FILENAME) != 0)
         TEST_ERROR;
 
@@ -290,8 +344,17 @@ test_file_fapl(void)
     if ((file_config = (H5F_vfd_swmr_config_t *)HDmalloc(sizeof(H5F_vfd_swmr_config_t))) == NULL)
         FAIL_STACK_ERROR;
 
-    /* Configured as VFD SWMR reader + no page buffering */
-    fapl1 = init_vfd_swmr_config_fapl(config1, 4, 6, FALSE, 2, MD_FILENAME, 0);
+
+    /* 
+     * 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);
+
+    /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
+    fapl1 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 0, config1);
     if (fapl1 == H5I_INVALID_HID)
         TEST_ERROR
 
@@ -307,8 +370,17 @@ test_file_fapl(void)
     if (H5Pclose(fapl1) < 0)
         FAIL_STACK_ERROR
 
-    /* Configured as VFD SWMR writer + no page buffering */
-    fapl1 = init_vfd_swmr_config_fapl(config1, 4, 6, TRUE, 2, MD_FILENAME, 0);
+    /* 
+     * 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);
+
+    /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
+    fapl1 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 0, config1);
+
     if (fapl1 == H5I_INVALID_HID)
         TEST_ERROR
 
@@ -321,13 +393,10 @@ test_file_fapl(void)
     if (fid >= 0)
         TEST_ERROR;
 
-    /* Create a copy of the file creation property list */
-    if ((fcpl = H5Pcreate(H5P_FILE_CREATE)) < 0)
+    if ((fcpl = vfd_swmr_create_fcpl(H5F_FSPACE_STRATEGY_PAGE, 4096)) < 0) {
+        HDprintf("vfd_swmr_create_fcpl() failed");
         FAIL_STACK_ERROR
-
-    /* Set file space strategy */
-    if (H5Pset_file_space_strategy(fcpl, H5F_FSPACE_STRATEGY_PAGE, FALSE, 1) < 0)
-        FAIL_STACK_ERROR;
+    }
 
     /* Should fail to create: no page buffering */
     H5E_BEGIN_TRY
@@ -341,8 +410,17 @@ test_file_fapl(void)
     if (H5Pclose(fapl1) < 0)
         FAIL_STACK_ERROR
 
-    /* Configured as VFD SWMR writer + page buffering */
-    fapl1 = init_vfd_swmr_config_fapl(config1, 4, 6, TRUE, 2, MD_FILENAME, 4096);
+    /* 
+     * 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);
+
+    /* 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)
         TEST_ERROR
 
@@ -404,8 +482,17 @@ test_file_fapl(void)
     if (H5Pclose(fapl1) < 0)
         FAIL_STACK_ERROR;
 
-    /* Set up different VFD SWMR configuration + page_buffering */
-    fapl2 = init_vfd_swmr_config_fapl(config2, 4, 10, TRUE, 2, MD_FILENAME, 4096);
+    /* 
+     * 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);
+
+    /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
+    fapl2 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config2);
+
     if (fapl2 == H5I_INVALID_HID)
         TEST_ERROR
 
@@ -435,10 +522,20 @@ test_file_fapl(void)
     /* The file previously opened as VDF SWMR writer is still open */
     /* with VFD SWMR configuration in config2 */
 
-    /* Set up as VFD SWMR writer in config1 but different from config2 */
-    fapl1 = init_vfd_swmr_config_fapl(config1, 3, 8, TRUE, 3, MD_FILENAME, 4096);
+
+    /* 
+     * 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);
+
+    /* 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)
-        TEST_ERROR;
+        TEST_ERROR
 
     /* Re-open the same file with config1 */
     /* Should fail to open since config1 is different from config2 setting */
@@ -454,10 +551,17 @@ test_file_fapl(void)
     if (H5Pclose(fapl1) < 0)
         FAIL_STACK_ERROR;
 
-    /* Set up as VFD SWMR reader in config1 which is same as config2 */
-    fapl1 = init_vfd_swmr_config_fapl(config1, 4, 10, TRUE, 2, MD_FILENAME, 4096);
+    /* 
+     * 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);
+
+    /* 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)
-        TEST_ERROR;
+        TEST_ERROR
 
     /* Re-open the same file as VFD SWMR writer */
     /* Should succeed since config1 is same as the setting in config2 */
@@ -530,6 +634,7 @@ error:
     return 1;
 } /* test_file_fapl() */
 
+
 /*-------------------------------------------------------------------------
  * Function:    test_file_end_tick()
  *
@@ -589,28 +694,52 @@ test_file_end_tick(void)
     if ((config3 = HDmalloc(sizeof(*config3))) == NULL)
         FAIL_STACK_ERROR;
 
-    /* Configured file 1 as VFD SWMR writer + page buffering */
-    fapl1 = init_vfd_swmr_config_fapl(config1, 10, 15, TRUE, 2, MD_FILENAME, 4096);
+    /* 
+     * 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);
+
+    /* 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;
+        TEST_ERROR
+
+    /* 
+     * 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);
+
+    /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
+    fapl2 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config2);
 
-    /* Configured file 2 as VFD SWMR writer + page buffering */
-    fapl2 = init_vfd_swmr_config_fapl(config2, 5, 6, TRUE, 2, MD_FILENAME2, 4096);
     if (fapl2 == H5I_INVALID_HID)
-        FAIL_STACK_ERROR;
+        TEST_ERROR
 
-    /* Configured file 3 as VFD SWMR writer + page buffering */
-    fapl3 = init_vfd_swmr_config_fapl(config3, 3, 6, TRUE, 2, MD_FILENAME3, 4096);
-    if (fapl3 == H5I_INVALID_HID)
-        FAIL_STACK_ERROR;
+    /* 
+     * Configured file 3 as VFD SWMR writer + page buffering 
+     */
 
-    /* Create a copy of the file creation property list */
-    if ((fcpl = H5Pcreate(H5P_FILE_CREATE)) < 0)
-        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(config3, 3, 6, TRUE, TRUE, FALSE, TRUE, 2, 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);
+
+    if (fapl3 == H5I_INVALID_HID)
+        TEST_ERROR
 
-    /* Set file space strategy */
-    if (H5Pset_file_space_strategy(fcpl, H5F_FSPACE_STRATEGY_PAGE, FALSE, 1) < 0)
+    if ((fcpl = vfd_swmr_create_fcpl(H5F_FSPACE_STRATEGY_PAGE, 4096)) < 0) {
+        HDprintf("vfd_swmr_create_fcpl() failed");
         FAIL_STACK_ERROR;
+    }
 
     /* Create file 1 with VFD SWMR writer */
     if ((fid1 = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl, fapl1)) < 0)
@@ -776,18 +905,23 @@ test_writer_create_open_flush(void)
     if ((my_config = HDmalloc(sizeof(H5F_vfd_swmr_config_t))) == NULL)
         FAIL_STACK_ERROR;
 
-    /* Set up the VFD SWMR configuration + page buffering */
-    fapl = init_vfd_swmr_config_fapl(my_config, 1, 3, TRUE, 2, MD_FILENAME, 4096);
-    if (fapl == H5I_INVALID_HID)
-        FAIL_STACK_ERROR;
+    /* 
+     * Set up the VFD SWMR configuration + page buffering 
+     */
 
-    /* Create a copy of the file creation property list */
-    if ((fcpl = H5Pcreate(H5P_FILE_CREATE)) < 0)
-        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, 2, MD_FILENAME, NULL);
 
-    /* Set file space strategy */
-    if (H5Pset_file_space_strategy(fcpl, H5F_FSPACE_STRATEGY_PAGE, FALSE, 1) < 0)
+    /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
+    fapl = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, my_config);
+    if (fapl == H5I_INVALID_HID)
+        TEST_ERROR
+
+    if ((fcpl = vfd_swmr_create_fcpl(H5F_FSPACE_STRATEGY_PAGE, 4096)) < 0) {
+        HDprintf("vfd_swmr_create_fcpl() failed");
         FAIL_STACK_ERROR;
+    }
 
     /* Create an HDF5 file with VFD SWMR configured */
     if ((fid = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl, fapl)) < 0)
@@ -797,7 +931,6 @@ test_writer_create_open_flush(void)
     if (H5F__vfd_swmr_writer_create_open_flush_test(fid, TRUE) < 0)
         FAIL_STACK_ERROR;
 
-#ifdef LATER /* Will activate the test when flush is implemented */
     /* Flush the HDF5 file */
     if (H5Fflush(fid, H5F_SCOPE_GLOBAL) < 0)
         FAIL_STACK_ERROR
@@ -805,7 +938,6 @@ test_writer_create_open_flush(void)
     /* Verify info in metadata file when flushing the HDF5 file */
     if (H5F__vfd_swmr_writer_create_open_flush_test(fid, FALSE) < 0)
         FAIL_STACK_ERROR
-#endif
 
     /* Close the file */
     if (H5Fclose(fid) < 0)
@@ -891,6 +1023,7 @@ test_writer_md(void)
     hsize_t        chunk_dims[2]     = {2, 5};                         /* Dataset chunked dimension sizes */
     H5FD_vfd_swmr_idx_entry_t *index = NULL;                           /* Pointer to the index entries */
     H5F_vfd_swmr_config_t *    my_config = NULL;                       /* Configuration for VFD SWMR */
+    H5F_t * f        = NULL;                                           /* Internal file object pointer */
 
     TESTING("Verify the metadata file for VFD SWMR writer");
 
@@ -898,25 +1031,28 @@ test_writer_md(void)
     if ((my_config = HDmalloc(sizeof(H5F_vfd_swmr_config_t))) == NULL)
         FAIL_STACK_ERROR;
 
-    /* Set up the VFD SWMR configuration + page buffering */
-    fapl = init_vfd_swmr_config_fapl(my_config, 1, 3, TRUE, 256, MD_FILENAME, FS_PAGE_SIZE);
-    if (fapl == 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(my_config, 1, 3, TRUE, TRUE, FALSE, TRUE, 256, MD_FILENAME, NULL);
 
-    /* Create a copy of the file creation property list */
-    if ((fcpl = H5Pcreate(H5P_FILE_CREATE)) < 0)
-        FAIL_STACK_ERROR
+    /* 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);
+    if (fapl == H5I_INVALID_HID)
+        TEST_ERROR
 
-    /* Set file space strategy */
-    if (H5Pset_file_space_strategy(fcpl, H5F_FSPACE_STRATEGY_PAGE, FALSE, 1) < 0)
-        FAIL_STACK_ERROR;
-    if (H5Pset_file_space_page_size(fcpl, FS_PAGE_SIZE) < 0)
+    if ((fcpl = vfd_swmr_create_fcpl(H5F_FSPACE_STRATEGY_PAGE, FS_PAGE_SIZE)) < 0) {
+        HDprintf("vfd_swmr_create_fcpl() failed");
         FAIL_STACK_ERROR;
+    }
 
     /* Create an HDF5 file with VFD SWMR configured */
     if ((fid = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl, fapl)) < 0)
         FAIL_STACK_ERROR;
 
+    /* Get a pointer to the internal file object */
+    if (NULL == (f = (H5F_t *)H5VL_object(fid)))
+        FAIL_STACK_ERROR;
+
     /* Allocate num_entries for the data buffer */
     if ((buf = HDcalloc(num_entries, FS_PAGE_SIZE)) == NULL)
         FAIL_STACK_ERROR;
@@ -932,6 +1068,7 @@ test_writer_md(void)
         index[i].md_file_page_offset = 1 + (num_entries - i) * 5;
         index[i].length              = (uint32_t)FS_PAGE_SIZE;
         index[i].entry_ptr           = &buf[i * FS_PAGE_SIZE];
+        index[i].tick_of_last_change = f->shared->tick_num;
     }
 
     /* Update with index and verify info in the metadata file */
@@ -970,8 +1107,10 @@ test_writer_md(void)
     }
 
     /* (B) Update every other entry in the index */
-    for (i = 0; i < num_entries; i += 2)
+    for (i = 0; i < num_entries; i += 2) {
         index[i].entry_ptr = &buf[i * FS_PAGE_SIZE];
+        index[i].tick_of_last_change = f->shared->tick_num;
+    }
 
     /* Update with index and verify info in the metadata file */
     /* Also verify that 5 entries will be on the delayed list */
@@ -1007,8 +1146,10 @@ test_writer_md(void)
     }
 
     /* (C) Update every 3 entry in the index */
-    for (i = 0; i < num_entries; i += 3)
+    for (i = 0; i < num_entries; i += 3) {
         index[i].entry_ptr = &buf[i * FS_PAGE_SIZE];
+        index[i].tick_of_last_change = f->shared->tick_num;
+    }
 
     /* Update with index and verify info in the metadata file */
     /* Also verify that 4 entries will be on the delayed list */
@@ -1042,7 +1183,9 @@ test_writer_md(void)
 
     /* (D) Update two entries in the index */
     index[1].entry_ptr = &buf[1 * FS_PAGE_SIZE];
+    index[1].tick_of_last_change = f->shared->tick_num;
     index[5].entry_ptr = &buf[5 * FS_PAGE_SIZE];
+    index[5].tick_of_last_change = f->shared->tick_num;
 
     /* Update with index and verify info in the metadata file */
     /* Also verify that 2 entries will be on the delayed list */
@@ -1202,21 +1345,23 @@ test_reader_md_concur(void)
     if ((config_writer = HDmalloc(sizeof(*config_writer))) == NULL)
         FAIL_STACK_ERROR;
 
-    /* Set up the VFD SWMR configuration + page buffering */
-    fapl_writer = init_vfd_swmr_config_fapl(config_writer, 1, 3, TRUE, 256, MD_FILENAME, FS_PAGE_SIZE);
-    if (fapl_writer == H5I_INVALID_HID)
-        FAIL_STACK_ERROR;
+    /* 
+     * Set up the VFD SWMR configuration + page buffering 
+     */
 
-    /* Create a copy of the file creation property list */
-    if ((fcpl = H5Pcreate(H5P_FILE_CREATE)) < 0)
-        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(config_writer, 1, 3, TRUE, TRUE, FALSE, TRUE, 256, MD_FILENAME, NULL);
 
-    /* Set file space strategy */
-    if (H5Pset_file_space_strategy(fcpl, H5F_FSPACE_STRATEGY_PAGE, FALSE, 1) < 0)
-        FAIL_STACK_ERROR;
+    /* 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);
+    if (fapl_writer == H5I_INVALID_HID)
+        TEST_ERROR
 
-    if (H5Pset_file_space_page_size(fcpl, FS_PAGE_SIZE) < 0)
+    if ((fcpl = vfd_swmr_create_fcpl(H5F_FSPACE_STRATEGY_PAGE, FS_PAGE_SIZE)) < 0) {
+        HDprintf("vfd_swmr_create_fcpl() failed");
         FAIL_STACK_ERROR;
+    }
 
     /* Create an HDF5 file with VFD SWMR configured */
     if ((fid_writer = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl, fapl_writer)) < 0)
@@ -1276,10 +1421,19 @@ test_reader_md_concur(void)
         if ((config_reader = HDmalloc(sizeof(*config_reader))) == NULL)
             HDexit(EXIT_FAILURE);
 
-        /* Set up the VFD SWMR configuration as reader + page buffering */
-        fapl_reader = init_vfd_swmr_config_fapl(config_reader, 1, 3, FALSE, 256, MD_FILENAME, FS_PAGE_SIZE);
+        /* 
+         * 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);
+
+        /* 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);
+
         if (fapl_reader == H5I_INVALID_HID)
-            HDexit(EXIT_FAILURE);
+            TEST_ERROR
 
         /* Open the test file as reader */
         if ((fid_reader = H5Fopen(FILENAME, H5F_ACC_RDONLY, fapl_reader)) < 0)
@@ -1479,6 +1633,9 @@ test_reader_md_concur(void)
     if ((fid_writer = H5Fopen(FILENAME, H5F_ACC_RDWR, fapl_writer)) < 0)
         FAIL_STACK_ERROR;
 
+    /* Get the file pointer */
+    file_writer = H5VL_object(fid_writer);
+
     /* Send notification 1 to reader to start verfication */
     notify = 1;
     if (HDwrite(parent_pfd[1], &notify, sizeof(int)) < 0)
@@ -1544,11 +1701,9 @@ test_reader_md_concur(void)
         index[i].md_file_page_offset = 1 + (num_entries - i) * 5;
         index[i].length              = (uint32_t)FS_PAGE_SIZE;
         index[i].entry_ptr           = &buf[i * FS_PAGE_SIZE];
+        index[i].tick_of_last_change = file_writer->shared->tick_num;
     }
 
-    /* Get the file pointer */
-    file_writer = H5VL_object(fid_writer);
-
     /* Update the metadata file with the index */
     if (H5F_update_vfd_swmr_metadata_file(file_writer, num_entries, index) < 0)
         TEST_ERROR;
@@ -1605,8 +1760,10 @@ test_reader_md_concur(void)
 
     /* Update 3 entries in the index */
     num_entries = 3;
-    for (i = 0; i < num_entries; i++)
+    for (i = 0; i < num_entries; i++) {
         index[i].entry_ptr = &buf[i * FS_PAGE_SIZE];
+        index[i].tick_of_last_change = file_writer->shared->tick_num;
+    }
 
     /* Update the metadata file with the index */
     if (H5F_update_vfd_swmr_metadata_file(file_writer, num_entries, index) < 0)
@@ -1658,8 +1815,10 @@ test_reader_md_concur(void)
 
     /* Update 5 entries in the index */
     num_entries = 5;
-    for (i = 0; i < num_entries; i++)
+    for (i = 0; i < num_entries; i++) {
         index[i].entry_ptr = &buf[i * FS_PAGE_SIZE];
+        index[i].tick_of_last_change = file_writer->shared->tick_num;
+    }
 
     /* Update the metadata file with the index */
     if (H5F_update_vfd_swmr_metadata_file(file_writer, num_entries, index) < 0)
@@ -1816,16 +1975,10 @@ test_multiple_file_opens_concur(void)
 
     TESTING("EOT queue entries when opening files concurrently with VFD SWMR");
 
-    /* Create a copy of the file creation property list */
-    if ((fcpl = H5Pcreate(H5P_FILE_CREATE)) < 0)
-        FAIL_STACK_ERROR
-
-    /* Set file space strategy */
-    if (H5Pset_file_space_strategy(fcpl, H5F_FSPACE_STRATEGY_PAGE, FALSE, 1) < 0)
-        FAIL_STACK_ERROR;
-
-    if (H5Pset_file_space_page_size(fcpl, FS_PAGE_SIZE) < 0)
+    if ((fcpl = vfd_swmr_create_fcpl(H5F_FSPACE_STRATEGY_PAGE, FS_PAGE_SIZE)) < 0) {
+        HDprintf("vfd_swmr_create_fcpl() failed");
         FAIL_STACK_ERROR;
+    }
 
     /* Create file A */
     if ((fid1 = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl, H5P_DEFAULT)) < 0)
@@ -1886,7 +2039,14 @@ test_multiple_file_opens_concur(void)
             HDexit(EXIT_FAILURE);
 
         /* Set the VFD SWMR configuration in fapl_writer + page buffering */
-        fapl_writer = init_vfd_swmr_config_fapl(config_writer, 1, 3, TRUE, 256, MD_FILENAME2, FS_PAGE_SIZE);
+
+        /* 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);
+
+        /* 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);
+
         if (fapl_writer == H5I_INVALID_HID)
             HDexit(EXIT_FAILURE);
 
@@ -1948,8 +2108,13 @@ test_multiple_file_opens_concur(void)
     if ((config1 = HDmalloc(sizeof(*config1))) == NULL)
         FAIL_STACK_ERROR
 
-    /* Set the VFD SWMR configuration in fapl1 + page buffering */
-    fapl1 = init_vfd_swmr_config_fapl(config1, 7, 10, TRUE, 256, MD_FILENAME, FS_PAGE_SIZE);
+    /* 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);
+
+    /* 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);
+
     if (fapl1 == H5I_INVALID_HID)
         FAIL_STACK_ERROR
 
@@ -1986,8 +2151,13 @@ test_multiple_file_opens_concur(void)
     if ((config2 = HDmalloc(sizeof(*config2))) == NULL)
         FAIL_STACK_ERROR
 
-    /* Set the VFD SWMR configuration in fapl2 + page buffering */
-    fapl2 = init_vfd_swmr_config_fapl(config2, 1, 3, FALSE, 256, MD_FILENAME2, FS_PAGE_SIZE);
+    /* 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);
+
+    /* 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);
+
     if (fapl2 == H5I_INVALID_HID)
         FAIL_STACK_ERROR
 
@@ -2120,21 +2290,24 @@ test_disable_enable_eot_concur(void)
     if ((config_writer = HDmalloc(sizeof(*config_writer))) == NULL)
         FAIL_STACK_ERROR;
 
-    /* Set up the VFD SWMR configuration + page buffering */
-    fapl_writer = init_vfd_swmr_config_fapl(config_writer, 1, 3, TRUE, 256, MD_FILENAME, FS_PAGE_SIZE);
-    if (fapl_writer == H5I_INVALID_HID)
-        FAIL_STACK_ERROR;
+    /* 
+     * Set up the VFD SWMR configuration + page buffering 
+     */
 
-    /* Create a copy of the file creation property list */
-    if ((fcpl = H5Pcreate(H5P_FILE_CREATE)) < 0)
-        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(config_writer, 1, 3, TRUE, TRUE, FALSE, TRUE, 256, MD_FILENAME, NULL);
 
-    /* Set file space strategy */
-    if (H5Pset_file_space_strategy(fcpl, H5F_FSPACE_STRATEGY_PAGE, FALSE, 1) < 0)
-        FAIL_STACK_ERROR;
+    /* 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);
 
-    if (H5Pset_file_space_page_size(fcpl, FS_PAGE_SIZE) < 0)
-        FAIL_STACK_ERROR;
+    if (fapl_writer == H5I_INVALID_HID)
+        FAIL_STACK_ERROR
+
+    if ((fcpl = vfd_swmr_create_fcpl(H5F_FSPACE_STRATEGY_PAGE, FS_PAGE_SIZE)) < 0) {
+        HDprintf("vfd_swmr_create_fcpl() failed");
+        FAIL_STACK_ERROR
+    }
 
     /* Create an HDF5 file with VFD SWMR configured */
     if ((fid_writer = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl, fapl_writer)) < 0)
@@ -2197,10 +2370,19 @@ test_disable_enable_eot_concur(void)
         if ((config_reader = HDmalloc(sizeof(*config_reader))) == NULL)
             HDexit(EXIT_FAILURE);
 
-        /* Set up the VFD SWMR configuration as reader + page buffering */
-        fapl_reader = init_vfd_swmr_config_fapl(config_reader, 1, 3, FALSE, 256, MD_FILENAME, FS_PAGE_SIZE);
+        /* 
+         * 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);
+
+        /* 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);
+
         if (fapl_reader == H5I_INVALID_HID)
-            FAIL_STACK_ERROR;
+            FAIL_STACK_ERROR
 
         /* Open the test file as reader */
         if ((fid_reader = H5Fopen(FILENAME, H5F_ACC_RDONLY, fapl_reader)) < 0)
@@ -2400,21 +2582,24 @@ test_file_end_tick_concur(void)
     if ((config_writer = HDmalloc(sizeof(*config_writer))) == NULL)
         FAIL_STACK_ERROR;
 
-    /* Set up the VFD SWMR configuration + page buffering */
-    fapl_writer = init_vfd_swmr_config_fapl(config_writer, 1, 3, TRUE, 256, MD_FILENAME, FS_PAGE_SIZE);
-    if (fapl_writer == H5I_INVALID_HID)
-        FAIL_STACK_ERROR;
+    /* 
+     * Set up the VFD SWMR configuration + page buffering 
+     */
 
-    /* Create a copy of the file creation property list */
-    if ((fcpl = H5Pcreate(H5P_FILE_CREATE)) < 0)
-        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(config_writer, 1, 3, TRUE, TRUE, FALSE, TRUE, 256, 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);
 
-    /* Set file space strategy */
-    if (H5Pset_file_space_strategy(fcpl, H5F_FSPACE_STRATEGY_PAGE, FALSE, 1) < 0)
+    if (fapl_writer == H5I_INVALID_HID)
         FAIL_STACK_ERROR;
 
-    if (H5Pset_file_space_page_size(fcpl, FS_PAGE_SIZE) < 0)
+    if ((fcpl = vfd_swmr_create_fcpl(H5F_FSPACE_STRATEGY_PAGE, FS_PAGE_SIZE)) < 0) {
+        HDprintf("vfd_swmr_create_fcpl() failed");
         FAIL_STACK_ERROR;
+    }
 
     /* Create an HDF5 file with VFD SWMR configured */
     if ((fid_writer = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl, fapl_writer)) < 0)
@@ -2477,10 +2662,15 @@ test_file_end_tick_concur(void)
         if ((config_reader = HDmalloc(sizeof(*config_reader))) == NULL)
             HDexit(EXIT_FAILURE);
 
-        /* Set up the VFD SWMR configuration as reader + page buffering */
-        fapl_reader = init_vfd_swmr_config_fapl(config_reader, 1, 3, FALSE, 256, MD_FILENAME, FS_PAGE_SIZE);
+        /* 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);
+
+        /* 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);
+
         if (fapl_reader == H5I_INVALID_HID)
-            FAIL_STACK_ERROR;
+            FAIL_STACK_ERROR
 
         /* Open the test file as reader */
         if ((fid_reader1 = H5Fopen(FILENAME, H5F_ACC_RDONLY, fapl_reader)) < 0)
@@ -2667,23 +2857,33 @@ test_multiple_file_opens(void)
     if ((config2 = HDmalloc(sizeof(*config2))) == NULL)
         FAIL_STACK_ERROR;
 
-    /* Configured as VFD SWMR writer + page buffering */
-    fapl1 = init_vfd_swmr_config_fapl(config1, 4, 6, TRUE, 2, MD_FILENAME, 4096);
+    /* 
+     * 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);
+
+    /* 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;
 
-    /* Configured as VFD SWMR writer + page buffering */
-    fapl2 = init_vfd_swmr_config_fapl(config2, 4, 6, TRUE, 2, MD_FILENAME2, 4096);
+    /* 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);
+
+    /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
+    fapl2 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config2);
+
     if (fapl2 == H5I_INVALID_HID)
         FAIL_STACK_ERROR;
 
-    /* Create a copy of the file creation property list */
-    if ((fcpl = H5Pcreate(H5P_FILE_CREATE)) < 0)
-        FAIL_STACK_ERROR
-
-    /* Set file space strategy */
-    if (H5Pset_file_space_strategy(fcpl, H5F_FSPACE_STRATEGY_PAGE, FALSE, 1) < 0)
+    if ((fcpl = vfd_swmr_create_fcpl(H5F_FSPACE_STRATEGY_PAGE, 4096)) < 0) {
+        HDprintf("vfd_swmr_create_fcpl() failed");
         FAIL_STACK_ERROR;
+    }
 
     /* Create a file without VFD SWMR */
     if ((fid = H5Fcreate(FNAME, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT)) < 0)
@@ -2854,13 +3054,10 @@ test_same_file_opens(void)
     if ((config2 = HDmalloc(sizeof(*config2))) == NULL)
         FAIL_STACK_ERROR;
 
-    /* Create a copy of the file creation property list */
-    if ((fcpl = H5Pcreate(H5P_FILE_CREATE)) < 0)
+    if ((fcpl = vfd_swmr_create_fcpl(H5F_FSPACE_STRATEGY_PAGE, 4096)) < 0) {
+        HDprintf("vfd_swmr_create_fcpl() failed");
         FAIL_STACK_ERROR
-
-    /* Set file space strategy */
-    if (H5Pset_file_space_strategy(fcpl, H5F_FSPACE_STRATEGY_PAGE, FALSE, 1) < 0)
-        FAIL_STACK_ERROR;
+    }
 
     /*
      * Tests for first column
@@ -2874,8 +3071,17 @@ test_same_file_opens(void)
     if (H5Fclose(fid) < 0)
         FAIL_STACK_ERROR;
 
-    /* Set the VFD SWMR configuration in fapl1 + page buffering */
-    fapl1 = init_vfd_swmr_config_fapl(config1, 4, 10, TRUE, 2, MD_FILENAME, 4096);
+    /* 
+     * 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);
+
+    /* 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;
 
@@ -2893,8 +3099,17 @@ test_same_file_opens(void)
     if (H5Fclose(fid2) < 0)
         FAIL_STACK_ERROR;
 
-    /* Set the VFD SWMR configuration in fapl2 + page buffering */
-    fapl2 = init_vfd_swmr_config_fapl(config2, 3, 8, FALSE, 3, MD_FILENAME, 4096);
+    /* 
+     * 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);
+
+    /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
+    fapl2 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config2);
+
     if (fapl2 == H5I_INVALID_HID)
         FAIL_STACK_ERROR;
 
@@ -2939,8 +3154,18 @@ test_same_file_opens(void)
      * Tests for second column
      */
 
-    /* Set up as VFD SWMR reader + page buffering */
-    fapl1 = init_vfd_swmr_config_fapl(config1, 4, 10, FALSE, 2, MD_FILENAME, 4096);
+
+    /* 
+     * 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);
+
+    /* 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;
 
@@ -2967,8 +3192,17 @@ test_same_file_opens(void)
     if ((fid = H5Fopen(FILENAME, H5F_ACC_RDWR, H5P_DEFAULT)) < 0)
         TEST_ERROR;
 
-    /* Set up as VFD SWMR writer + page buffering */
-    fapl1 = init_vfd_swmr_config_fapl(config1, 4, 10, TRUE, 2, MD_FILENAME, 4096);
+    /* 
+     * 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);
+
+    /* 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;
 
@@ -3014,8 +3248,17 @@ test_same_file_opens(void)
     if ((fid = H5Fopen(FILENAME, H5F_ACC_RDONLY, H5P_DEFAULT)) < 0)
         TEST_ERROR;
 
-    /* Set up as VFD SWMR writer + page buffering */
-    fapl1 = init_vfd_swmr_config_fapl(config1, 4, 10, TRUE, 2, MD_FILENAME, 4096);
+    /* 
+     * 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);
+
+    /* 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;
 
@@ -3216,28 +3459,52 @@ test_enable_disable_eot(void)
     if ((config3 = HDmalloc(sizeof(*config3))) == NULL)
         FAIL_STACK_ERROR;
 
-    /* Configured first file as VFD SWMR writer + page buffering */
-    fapl1 = init_vfd_swmr_config_fapl(config1, 4, 6, TRUE, 2, MD_FILENAME, 4096);
+    /* 
+     * 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);
+
+    /* 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;
 
-    /* Configured second file as VFD SWMR writer + page buffering */
-    fapl2 = init_vfd_swmr_config_fapl(config2, 4, 6, TRUE, 2, MD_FILENAME2, 4096);
+    /* 
+     * 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);
+
+    /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
+    fapl2 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config2);
+
     if (fapl2 == H5I_INVALID_HID)
         FAIL_STACK_ERROR;
 
-    /* Configured third file as VFD SWMR writer + page buffering */
-    fapl3 = init_vfd_swmr_config_fapl(config3, 4, 6, TRUE, 2, MD_FILENAME3, 4096);
+    /* 
+     * 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);
+
+    /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
+    fapl3 = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config3);
+
     if (fapl3 == H5I_INVALID_HID)
         FAIL_STACK_ERROR;
 
-    /* Create a copy of the file creation property list */
-    if ((fcpl = H5Pcreate(H5P_FILE_CREATE)) < 0)
+    if ((fcpl = vfd_swmr_create_fcpl(H5F_FSPACE_STRATEGY_PAGE, 4096)) < 0) {
+        HDprintf("vfd_swmr_create_fcpl() failed");
         FAIL_STACK_ERROR
-
-    /* Set file space strategy */
-    if (H5Pset_file_space_strategy(fcpl, H5F_FSPACE_STRATEGY_PAGE, FALSE, 1) < 0)
-        FAIL_STACK_ERROR;
+    }
 
     /* Create a file without VFD SWMR */
     if ((fid = H5Fcreate(FNAME, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT)) < 0)
@@ -3425,6 +3692,703 @@ error:
 } /* test_enable_disable_eot() */
 
 /*-------------------------------------------------------------------------
+ * Function:    verify_updater_flags()
+ *
+ * Purpose:     This is the helper routine used to verify whether
+ *              "flags" in the updater file is as expected.
+ *
+ * Return:      0 if test is sucessful
+ *              1 if test fails
+ *
+ * Programmer:  Vailin Choi; October 2021
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+verify_updater_flags(char *ud_name, uint16_t expected_flags)
+{
+    FILE* ud_fp;        /* Updater file pointer */
+    uint16_t flags;
+    size_t ret;         /* Return value */
+
+    
+    /* Open the updater file */
+    if((ud_fp = HDfopen(ud_name, "r")) == NULL)
+        FAIL_STACK_ERROR;
+
+    /* Seek to the position of "flags" in the updater file's header */
+    if(HDfseek(ud_fp, (HDoff_t)UD_HD_FLAGS_OFFSET, SEEK_SET) < 0)
+        FAIL_STACK_ERROR;
+
+    /* Read "flags" from the updater file */
+    if((ret = HDfread(&flags, UD_SIZE_2, 1, ud_fp)) != (size_t)1)
+        FAIL_STACK_ERROR;
+
+    if (flags != expected_flags)
+        TEST_ERROR;
+
+    if (HDfclose(ud_fp) < 0)
+        FAIL_STACK_ERROR;
+
+    return 0;
+
+error:
+    return 1;
+
+} /* verify_updater_flags() */
+
+/*-------------------------------------------------------------------------
+ * Function:    test_updater_flags
+ *
+ * Purpose:     Verify "flags" in the updater file is as expected for 
+ *              file creation.
+ *
+ * Return:      0 if test is sucessful
+ *              1 if test fails
+ *
+ * Programmer:  Vailin Choi; October 2021
+ *
+ *-------------------------------------------------------------------------
+ */
+static unsigned
+test_updater_flags(void)
+{
+    hid_t                  fid         = -1;   /* File ID */
+    hid_t                  fcpl        = -1;   /* File creation property list ID */
+    hid_t                  fapl        = -1;   /* File access property list ID */
+    hid_t                  file_fapl   = -1;   /* File access property list ID associated with the file */
+    H5F_vfd_swmr_config_t *config      = NULL; /* Configuration for VFD SWMR */
+    H5F_vfd_swmr_config_t *file_config = NULL; /* Configuration for VFD SWMR */
+    uint64_t seq_num = 0;                      /* Sequence number for updater file */
+    uint64_t i = 0;                             /* Local index variable */
+    char namebuf[H5F__MAX_VFD_SWMR_FILE_NAME_LEN];  /* Updater file path */
+    h5_stat_t sb;                               /* Info returned by stat system call */
+
+    TESTING("VFD SWMR updater file flags");
+
+    /* Should succeed without VFD SWMR configured */
+    if ((fid = H5Fcreate(FILENAME, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        TEST_ERROR;
+
+    /* Close the file  */
+    if (H5Fclose(fid) < 0)
+        FAIL_STACK_ERROR;
+
+    /* Allocate memory for the configuration structure */
+    if ((config = (H5F_vfd_swmr_config_t *)HDmalloc(sizeof(H5F_vfd_swmr_config_t))) == NULL)
+        FAIL_STACK_ERROR;
+    if ((file_config = (H5F_vfd_swmr_config_t *)HDmalloc(sizeof(H5F_vfd_swmr_config_t))) == NULL)
+        FAIL_STACK_ERROR;
+
+    /* 
+     * 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);
+
+    /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
+    fapl = vfd_swmr_create_fapl(FALSE, TRUE, FALSE, 4096, config);
+
+    if (fapl == H5I_INVALID_HID)
+        TEST_ERROR
+
+    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)
+        TEST_ERROR;
+
+    /* Get the file's file access property list */
+    if ((file_fapl = H5Fget_access_plist(fid)) < 0)
+        FAIL_STACK_ERROR;
+
+    /* Retrieve the VFD SWMR configuration from file_fapl */
+    if (H5Pget_vfd_swmr_config(file_fapl, file_config) < 0)
+        TEST_ERROR;
+
+    /* Verify the retrieved info is the same as config1 */
+    if (HDmemcmp(config, file_config, sizeof(H5F_vfd_swmr_config_t)) != 0)
+        TEST_ERROR;
+
+    /* Verify the first updater file: "flags" field and file size */
+    HDsprintf(namebuf, "%s.%lu", UD_FILENAME, seq_num);
+
+    /* Verify "flags" of the first updater file */
+    if(verify_updater_flags(namebuf, CREATE_METADATA_FILE_ONLY_FLAG) < 0)
+        TEST_ERROR;
+
+    /* Check updater file size */
+    if (HDstat(namebuf, &sb) == 0 && sb.st_size != H5F_UD_HEADER_SIZE)
+        TEST_ERROR;
+
+    /* Closing */
+    if (H5Fclose(fid) < 0)
+        FAIL_STACK_ERROR;
+
+    /* Look for the last updater file */
+    for (seq_num = 0; ; seq_num++) {
+        HDsprintf(namebuf, "%s.%lu", UD_FILENAME, seq_num);
+        if (HDaccess(namebuf, F_OK) != 0)
+            break;
+    }
+    HDsprintf(namebuf, "%s.%lu", UD_FILENAME, seq_num-1);
+
+    /* Verify "flags" of the last updater file */
+    if(verify_updater_flags(namebuf, FINAL_UPDATE_FLAG) < 0)
+        TEST_ERROR;
+
+    if (H5Pclose(file_fapl) < 0)
+        FAIL_STACK_ERROR;
+    if (H5Pclose(fapl) < 0)
+        FAIL_STACK_ERROR;
+    if (H5Pclose(fcpl) < 0)
+        FAIL_STACK_ERROR;
+
+    /* Remove updater files */
+    for (i = 0; i < seq_num; i++) {
+        HDsprintf(namebuf, "%s.%lu", UD_FILENAME, i);
+        HDremove(namebuf);
+    }
+
+    /* Free buffers */
+    if (config)
+        HDfree(config);
+    if (file_config)
+        HDfree(file_config);
+
+    PASSED();
+    return 0;
+
+error:
+    H5E_BEGIN_TRY
+    {
+        H5Pclose(fapl);
+        H5Pclose(file_fapl);
+        H5Pclose(fcpl);
+        H5Fclose(fid);
+    }
+    H5E_END_TRY;
+    if (config)
+        HDfree(config);
+    if (file_config)
+        HDfree(file_config);
+
+    return 1;
+} /* test_updater_flags() */
+
+/*-------------------------------------------------------------------------
+ * Function:    test_updater_flags_same_file_opens()
+ *
+ * Purpose:     Verify "flags" in the updater file is as expected for 
+ *              multiple opens of the same file.
+ *
+ * Return:      0 if test is sucessful
+ *              1 if test fails
+ *
+ * Programmer:  Vailin Choi; October 2021
+ *
+ *-------------------------------------------------------------------------
+ */
+static unsigned
+test_updater_flags_same_file_opens(void)
+{
+    hid_t                  fid     = -1;    /* File ID */
+    hid_t                  fid2    = -1;    /* File ID */
+    hid_t                  fcpl    = -1;    /* File creation property list ID */
+    hid_t                  fapl1   = -1;    /* File access property list ID */
+    H5F_vfd_swmr_config_t *config1 = NULL;  /* Configuration for VFD SWMR */
+    uint64_t seq_num = 0;                   /* Sequence number for updater file */
+    uint64_t i = 0;                         /* Local index variable */
+    char namebuf[H5F__MAX_VFD_SWMR_FILE_NAME_LEN];  /* Updater file path */
+
+    TESTING("VFD SWMR updater file flags for multiple opens of the same file");
+
+    /* Should succeed without VFD SWMR configured */
+    if ((fid = H5Fcreate(FILENAME, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        TEST_ERROR;
+
+    /* Close the file  */
+    if (H5Fclose(fid) < 0)
+        FAIL_STACK_ERROR;
+
+    /* Allocate memory for the configuration structure */
+    if ((config1 = HDmalloc(sizeof(*config1))) == NULL)
+        FAIL_STACK_ERROR;
+
+    if ((fcpl = vfd_swmr_create_fcpl(H5F_FSPACE_STRATEGY_PAGE, 4096)) < 0) {
+        HDprintf("vfd_swmr_create_fcpl() failed");
+        FAIL_STACK_ERROR
+    }
+
+    /* Create the test file */
+    if ((fid = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl, H5P_DEFAULT)) < 0)
+        TEST_ERROR;
+
+    /* Close the file */
+    if (H5Fclose(fid) < 0)
+        FAIL_STACK_ERROR;
+
+    /* 
+     * 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);
+
+    /* 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;
+
+    /* Open the file as VFD SWMR writer */
+    /* Keep the file open */
+    if ((fid = H5Fopen(FILENAME, H5F_ACC_RDWR, fapl1)) < 0)
+        TEST_ERROR;
+
+    /* Open the same file again as VFD SWMR writer */
+    /* Should succeed: 1st open--VFD SWMR writer, 2nd open--VFD SWMR writer */
+    if ((fid2 = H5Fopen(FILENAME, H5F_ACC_RDWR, fapl1)) < 0)
+        TEST_ERROR;
+
+    /* Close the second file open */
+    if (H5Fclose(fid2) < 0)
+        FAIL_STACK_ERROR;
+
+
+    /* Verify the first updater file for first file open */
+    HDsprintf(namebuf, "%s.%lu", UD_FILENAME, seq_num);
+
+    /* Verify "flags" of the first updater file is 0*/
+    if(verify_updater_flags(namebuf, 0) < 0)
+        TEST_ERROR;
+
+    /* Look for the last updater file */
+    for (seq_num = 0; ; seq_num++) {
+        HDsprintf(namebuf, "%s.%lu", UD_FILENAME, seq_num);
+        if (HDaccess(namebuf, F_OK) != 0)
+            break;
+    }
+    HDsprintf(namebuf, "%s.%lu", UD_FILENAME, seq_num-1);
+
+    /* Verify "flags" of the last updater file is 0 */
+    if(verify_updater_flags(namebuf, 0) < 0)
+        TEST_ERROR;
+
+    /* Close the 1st open file */
+    if (H5Fclose(fid) < 0)
+        FAIL_STACK_ERROR;
+
+    /* Look for the last updater file */
+    for (seq_num = 0; ; seq_num++) {
+        HDsprintf(namebuf, "%s.%lu", UD_FILENAME, seq_num);
+        if (HDaccess(namebuf, F_OK) != 0)
+            break;
+    }
+    HDsprintf(namebuf, "%s.%lu", UD_FILENAME, seq_num-1);
+
+    /* Verify "flags" of the last updater file after closing file */
+    if(verify_updater_flags(namebuf, FINAL_UPDATE_FLAG) < 0)
+        TEST_ERROR;
+
+    /* Clean up updater files */
+    for (i = 0; i < seq_num; i++) {
+        HDsprintf(namebuf, "%s.%lu", UD_FILENAME, i);
+        HDremove(namebuf);
+    }
+
+    if (H5Pclose(fcpl) < 0)
+        FAIL_STACK_ERROR;
+
+    /* Free buffers */
+    if (config1)
+        HDfree(config1);
+
+    PASSED();
+    return 0;
+
+error:
+    H5E_BEGIN_TRY
+    {
+        H5Pclose(fapl1);
+        H5Pclose(fcpl);
+        H5Fclose(fid);
+        H5Fclose(fid2);
+    }
+    H5E_END_TRY;
+    if (config1)
+        HDfree(config1);
+    return 1;
+} /* test_updater_flags_same_file_opens() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    clean_chk_ud_files()
+ *
+ * Purpose:     This is the helper routine used to clean up
+ *              the checksum file and the updater files.
+ *
+ * Return:      void
+ *
+ * Programmer:  Vailin Choi; October 2021
+ *
+ *-------------------------------------------------------------------------
+ */
+static void
+clean_chk_ud_files(char *md_file_path, char *updater_file_path)
+{
+    char chk_name[1024 + 4];
+    char ud_name[1024 + 4];
+    uint64_t i;
+
+    /* Name of the checksum file: <md_file_path>.chk */
+    HDsprintf(chk_name, "%s.chk", md_file_path);
+
+    /* Remove the checksum file if exists. 
+       If not, the callback will just continue appending
+       checksums to the existing file */
+    if(HDaccess(chk_name, F_OK) == 0) {
+        HDremove(chk_name);
+    }
+
+    /* Remove all the updater files if exist: <updater_file_path>.<i> */
+    for(i = 0; ; i++) {
+        sprintf(ud_name, "%s.%lu", updater_file_path, i);
+        if(HDaccess(ud_name, F_OK) != 0) 
+            break;
+        HDremove(ud_name);
+    }
+
+} /* clean_chk_ud_files() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    verify_ud_chk()
+ *
+ * Purpose:     This is the helper routine used by 
+ *              test_updater_generate_md_checksums() to verify 
+ *              contents of the checksum file and the updater files.
+ *              --verify the sequence number in each updater's file header
+ *                corresponds to the ith sequence number of the updater 
+ *                file name.
+ *              --verify the tick number in each updater's file header 
+ *                corresponds to the tick number stored in the checksum file
+ *              --verify the change_list_len in each updater's file header
+ *                is consistent with num_change_list_entries in each updater's
+ *                change list header
+ *
+ * Return:      0 if test is sucessful
+ *              1 if test fails
+ *
+ * Programmer:  Vailin Choi; October 2021
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+verify_ud_chk(char *md_file_path, char *ud_file_path)
+{
+    char chk_name[1024 + 4];        /* Checksum file name */
+    char ud_name[1024 + 4];         /* Updater file name */
+    FILE* chk_fp;                   /* Checksum file pointer */
+    FILE* ud_fp;                    /* Updater file pointer */
+    uint64_t ud_seq_num;            /* Sequence number in the updater file */
+    uint64_t chk_ud_seq_num;        /* Updater sequence number in the checksum file */
+    uint64_t i;                     /* Local index variable */
+    long size = 0;                  /* Size of the file */
+    size_t change_list_len;         /* change_list_len in the updater file header */
+    uint32_t num_change_list_entries;  /* num_change_list_entries in the updater change list header */
+
+    /* Open the checksum file */
+    HDsprintf(chk_name, "%s.chk", md_file_path);
+    if((chk_fp = HDfopen(chk_name, "r")) == NULL)
+        FAIL_STACK_ERROR;
+
+    for(i = 0; ; i++) {
+        /* Generate updater file name: <ud_file_path>.<i> */
+        HDsprintf(ud_name, "%s.%lu", ud_file_path, i);
+
+        /* Open the updater file */
+        if ((ud_fp = HDfopen(ud_name, "r")) == NULL)
+            break;
+        else {
+            /* Seek to the position of the sequence number in the updater file's header */
+            if(HDfseek(ud_fp, (off_t)UD_HD_SEQ_NUM_OFFSET, SEEK_SET) < 0)
+                FAIL_STACK_ERROR;
+
+            /* Read the sequence number from the updater file */
+            if(HDfread(&ud_seq_num, UD_SIZE_8, 1, ud_fp) != 1)
+                FAIL_STACK_ERROR;
+
+            /* Compare the sequence number with i */
+            if(ud_seq_num != i)
+                TEST_ERROR;
+
+            /* Read change_list_len from updater file's header */
+            if(HDfseek(ud_fp, (off_t)UD_HD_CHANGE_LIST_LEN_OFFSET, SEEK_SET) < 0)
+                FAIL_STACK_ERROR;
+
+            if(HDfread(&change_list_len, UD_SIZE_8, 1, ud_fp) != 1)
+                FAIL_STACK_ERROR;
+
+            if(i != 0) {
+            
+                /* Read num_change_list_entries from updater file's change list */
+                if(HDfseek(ud_fp, (off_t)UD_CL_NUM_CHANGE_LIST_ENTRIES_OFFSET, SEEK_SET) < 0)
+                    FAIL_STACK_ERROR;
+
+                if(HDfread(&num_change_list_entries, UD_SIZE_4, 1, ud_fp) != 1)
+                    FAIL_STACK_ERROR;
+
+                if(num_change_list_entries == 0) {
+                    if(change_list_len != H5F_UD_CL_SIZE(0))
+                        TEST_ERROR;
+                } else {
+                    if (change_list_len != H5F_UD_CL_SIZE(num_change_list_entries))
+                        TEST_ERROR
+                }
+            }
+
+            /* Close the updater file */
+            if(HDfclose(ud_fp) < 0)
+                FAIL_STACK_ERROR;
+
+            /* Read the updater sequence number from checksum file */
+            if(HDfread(&chk_ud_seq_num, UD_SIZE_8, 1, chk_fp) != 1)
+                FAIL_STACK_ERROR;
+
+            /* Compare sequence number in updater file with sequence number in checksum file */
+            if (ud_seq_num != chk_ud_seq_num)
+                TEST_ERROR;
+
+            /* Advance checksum file to the next sequence number */
+            if(HDfseek(chk_fp, (off_t)UD_SIZE_4, SEEK_CUR) < 0)
+                FAIL_STACK_ERROR;
+        }
+    }
+
+    /* Get the size of the chksum file */
+    if ((size = HDftell(chk_fp)) < 0)
+        FAIL_STACK_ERROR;
+
+    /* Size of sequence number and checksum in the checksum file */
+    if((unsigned)size != (i * (UD_SIZE_8 + UD_SIZE_4)))
+        TEST_ERROR;
+
+    return 0;
+
+error:
+    return (-1);
+
+}  /* verify_ud_chk() */
+
+/*-------------------------------------------------------------------------
+ * Function:    md_ck_cb()
+ *
+ * Purpose:     This is the callback function used by 
+ *              test_updater_generate_md_checksums() when the 
+ *              H5F_ACS_GENERATE_MD_CK_CB_NAME property is set in fapl.
+ *                  --Opens and read the metadata file into a buffer.
+ *                  --Generate checksum for the metadata file 
+ *                  --Write the tick number and the checksum to the checksum file
+ *
+ * Return:      0 if test is sucessful
+ *              1 if test fails
+ *
+ * Programmer:  Vailin Choi; October 2021
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t 
+md_ck_cb(char *md_file_path, uint64_t updater_seq_num)
+{
+    FILE* md_fp = NULL;     /* Metadata file pointer */
+    FILE* chk_fp = NULL;    /* Checksum file pointer */
+    long size = 0;          /* File size returned from HDftell() */
+    void *buf = NULL;       /* Buffer for holding the metadata file content */
+    uint32_t chksum = 0;    /* The checksum generated for the metadata file */
+    char chk_name[1024 + 4];    /* Buffer for the checksum file name */
+    size_t ret;             /* Return value */
+
+    /* Open the metadata file */
+    if((md_fp = HDfopen(md_file_path, "r")) == NULL)
+        FAIL_STACK_ERROR;
+
+    /* Set file pointer at end of file.*/
+    if(HDfseek(md_fp, 0, SEEK_END) < 0)
+        FAIL_STACK_ERROR;
+
+    /* Get the current position of the file pointer.*/
+    if ((size = HDftell(md_fp)) < 0)
+        FAIL_STACK_ERROR;
+
+    if(size != 0) {
+
+        HDrewind(md_fp);
+
+        if((buf = HDmalloc((size_t)size)) == NULL)
+            FAIL_STACK_ERROR;
+
+        /* Read the metadata file to buf */
+        if ((ret = HDfread(buf, 1, (size_t)size, md_fp)) != (size_t)size)
+            FAIL_STACK_ERROR;
+
+        /* Calculate checksum of the metadata file */
+        chksum = H5_checksum_metadata(buf, (size_t)size, 0);
+    }
+
+    /* Close the metadata file */
+    if(md_fp && HDfclose(md_fp) < 0)
+        FAIL_STACK_ERROR;
+
+    /*
+     *  Checksum file
+     */
+
+    /* Generate checksum file name: <md_file_path>.chk */
+    HDsprintf(chk_name, "%s.chk", md_file_path);
+
+    /* Open checksum file for append */
+    if((chk_fp = HDfopen(chk_name, "a")) == NULL)
+        FAIL_STACK_ERROR;
+
+    /* Write the updater sequence number to the checksum file */
+    if((ret = HDfwrite(&updater_seq_num, sizeof(uint64_t), 1, chk_fp)) != 1)
+        FAIL_STACK_ERROR;
+
+    /* Write the checksum to the checksum file */
+    if((ret = HDfwrite(&chksum, sizeof(uint32_t), 1, chk_fp)) != 1)
+        FAIL_STACK_ERROR;
+
+    /* Close the checksum file */
+    if(chk_fp && HDfclose(chk_fp) != 0)
+        FAIL_STACK_ERROR;
+
+    if(buf) 
+        HDfree(buf);
+
+    return 0;
+
+error:
+    if(buf) 
+        HDfree(buf);
+    if(md_fp)
+        HDfclose(md_fp);
+    if(chk_fp)
+        HDfclose(chk_fp);
+
+    return -1;
+}  /* md_ck_cb() */
+
+/*-------------------------------------------------------------------------
+ * Function:    test_updater_generate_md_checksums()
+ *
+ * Purpose:     It enables the generation of checksums for the metadata file
+ *              created by the writer end of tick function.
+ *              It also verifies the contents of the checksum file and the
+ *              updater files.
+ *
+ *              The test is invoked when the file is created via H5Fcreate()
+ *              and via H5Fopen().
+ *
+ * Return:      0 if test is sucessful
+ *              1 if test fails
+ *
+ * Programmer:  Vailin Choi; October 2021
+ *
+ * Note: It is important to clean up the checksum file and the updater files.
+ *
+ *-------------------------------------------------------------------------
+ */
+static unsigned
+test_updater_generate_md_checksums(hbool_t file_create)
+{
+    hid_t                  fid         = -1;   /* File ID */
+    hid_t                  fcpl        = -1;   /* File creation property list ID */
+    hid_t                  fapl        = -1;   /* File access property list ID */
+    H5F_vfd_swmr_config_t config;              /* Configuration for VFD SWMR */
+    H5F_generate_md_ck_cb_t cb_info;           /* Callback */
+
+    if(file_create) {
+        TESTING("VFD SWMR updater generate checksums for metadata file with H5Fcreate");
+    } else {
+        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);
+
+    /* use_latest_format, use_vfd_swmr, only_meta_page, page_buf_size, config */
+    fapl = vfd_swmr_create_fapl(TRUE, TRUE, FALSE, 4096, &config);
+
+    if (fapl == H5I_INVALID_HID)
+        TEST_ERROR
+
+    if ((fcpl = vfd_swmr_create_fcpl(H5F_FSPACE_STRATEGY_PAGE, 4096)) < 0) {
+        HDprintf("vfd_swmr_create_fcpl() failed");
+        FAIL_STACK_ERROR
+    }
+
+    /* Set up callback to generate checksums for updater's metadata files */
+    cb_info.func = md_ck_cb;
+
+    /* Activate private property to generate checksums for updater's metadata file */
+    H5Pset(fapl, H5F_ACS_GENERATE_MD_CK_CB_NAME, &cb_info);
+
+    /* Use file creation or file open for testing */
+    if(file_create) {
+        if((fid = H5Fcreate(FILENAME4, H5F_ACC_TRUNC, fcpl, fapl)) < 0)
+            TEST_ERROR;
+    } else {
+        fid = H5Fcreate(FILENAME4, H5F_ACC_TRUNC, fcpl, H5P_DEFAULT);
+        H5Fclose(fid);
+
+        fid = H5Fopen(FILENAME4, H5F_ACC_RDWR, fapl);
+    }
+
+    /* Close the file  */
+    if (H5Fclose(fid) < 0)
+        FAIL_STACK_ERROR;
+
+    if (H5Pclose(fapl) < 0)
+        FAIL_STACK_ERROR;
+    if (H5Pclose(fcpl) < 0)
+        FAIL_STACK_ERROR;
+
+    /* Verify contents of checksum file and updater files */
+    if(verify_ud_chk(config.md_file_path, config.updater_file_path) < 0)
+        TEST_ERROR;
+
+    /*  It's important to clean up the chechsum and updater files. */
+    clean_chk_ud_files(config.md_file_path, config.updater_file_path);
+
+    PASSED();
+
+    return 0;
+
+error:
+    H5E_BEGIN_TRY
+    {
+        H5Pclose(fapl);
+        H5Pclose(fcpl);
+        H5Fclose(fid);
+    }
+    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);
+
+    return 1;
+
+} /* test_updater_generate_md_checksums() */
+
+
+/*-------------------------------------------------------------------------
  * Function:    main()
  *
  * Purpose:     Main function for VFD SWMR tests.
@@ -3481,9 +4445,15 @@ main(void)
         PUTS_ERROR("Can't get VFD-dependent fapl")
     }
 
+    /* Add nfs/updater testing in this routine */
     nerrors += test_fapl();
 
     if (use_file_locking) {
+        nerrors += test_updater_flags();
+        nerrors += test_updater_flags_same_file_opens();
+        nerrors += test_updater_generate_md_checksums(TRUE);
+        nerrors += test_updater_generate_md_checksums(FALSE);
+
         nerrors += test_shadow_index_lookup();
 
         nerrors += test_file_fapl();
diff --git a/test/vfd_swmr_addrem_writer.c b/test/vfd_swmr_addrem_writer.c
index f115d2e..a2982fd 100644
--- a/test/vfd_swmr_addrem_writer.c
+++ b/test/vfd_swmr_addrem_writer.c
@@ -94,8 +94,9 @@ open_skeleton(const char *filename, unsigned verbose)
     if ((config = HDcalloc(1, sizeof(*config))) == NULL)
         goto error;
 
-    /* config, tick_len, max_lag, writer, flush_raw_data, md_pages_reserved, md_file_path */
-    init_vfd_swmr_config(config, 4, 5, TRUE, TRUE, 128, "./rw-shadow");
+     /* 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);
 
     /* 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 f445321..a722f44 100644
--- a/test/vfd_swmr_attrdset_writer.c
+++ b/test/vfd_swmr_attrdset_writer.c
@@ -1979,8 +1979,9 @@ main(int argc, char **argv)
         TEST_ERROR;
     }
 
-    /* config, tick_len, max_lag, writer, flush_raw_data, md_pages_reserved, md_file_path */
-    init_vfd_swmr_config(&config, 4, 7, writer, true, 128, "./attrdset-shadow");
+    /* 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);
 
     /* 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 77c7b26..928f7c7 100644
--- a/test/vfd_swmr_bigset_writer.c
+++ b/test/vfd_swmr_bigset_writer.c
@@ -2470,9 +2470,9 @@ main(int argc, char **argv)
             continue;
         }
 
-        /* config, tick_len, max_lag, writer, flush_raw_data, md_pages_reserved, md_file_path */
-        init_vfd_swmr_config(&config, s.tick_len, s.max_lag, s.writer, s.flush_raw_data, 128,
-                             "./bigset-shadow-%zu", i);
+        /* 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, s.writer, TRUE, FALSE, s.flush_raw_data, 128, "./bigset-shadow-%zu", NULL, i);
 
         /* 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, s.page_buf_size, &config)) < 0) {
diff --git a/test/vfd_swmr_common.c b/test/vfd_swmr_common.c
index cfe93aa..90abeed 100644
--- a/test/vfd_swmr_common.c
+++ b/test/vfd_swmr_common.c
@@ -345,10 +345,10 @@ await_signal(hid_t fid)
 
 /* Revised support routines that can be used for all VFD SWMR integration tests
  */
-/* Initialize fields in config with the input parameters */
 void
 init_vfd_swmr_config(H5F_vfd_swmr_config_t *config, uint32_t tick_len, uint32_t max_lag, hbool_t writer,
-                     hbool_t flush_raw_data, uint32_t md_pages_reserved, const char *md_file_fmtstr, ...)
+                      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, ...)
 {
     va_list ap;
 
@@ -360,13 +360,20 @@ init_vfd_swmr_config(H5F_vfd_swmr_config_t *config, uint32_t tick_len, uint32_t
     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;
 
-    HDva_start(ap, md_file_fmtstr);
+    HDva_start(ap, updater_file_path);
+
     evsnprintf(config->md_file_path, 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);
+
 } /* init_vfd_swmr_config() */
 
 /* Initialize the log file path in config, this function should be called after init_vfd_swmr_config.  */
diff --git a/test/vfd_swmr_common.h b/test/vfd_swmr_common.h
index f5981a5..42569be 100644
--- a/test/vfd_swmr_common.h
+++ b/test/vfd_swmr_common.h
@@ -73,9 +73,11 @@ H5TEST_DLL void await_signal(hid_t);
 H5TEST_DLL hid_t vfd_swmr_create_fapl(bool use_latest_format, bool use_vfd_swmr, bool only_meta_pages,
                                       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 flush_raw_data, uint32_t md_pages_reserved,
-                                     const char *md_file_fmtstr, ...) H5_ATTR_FORMAT(printf, 7, 8);
+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);
 
 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 d264ca9..3cf43f9 100644
--- a/test/vfd_swmr_dsetchks_writer.c
+++ b/test/vfd_swmr_dsetchks_writer.c
@@ -2302,8 +2302,9 @@ main(int argc, char **argv)
         TEST_ERROR;
     }
 
-    /* config, tick_len, max_lag, writer, flush_raw_data, md_pages_reserved, md_file_path */
-    init_vfd_swmr_config(&config, 4, 7, writer, s.flush_raw_data, 128, "./dsetchks-shadow");
+    /* 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);
 
     /* 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 3704c44..d999d64 100644
--- a/test/vfd_swmr_dsetops_writer.c
+++ b/test/vfd_swmr_dsetops_writer.c
@@ -1888,8 +1888,9 @@ main(int argc, char **argv)
         TEST_ERROR;
     }
 
-    /* config, tick_len, max_lag, writer, flush_raw_data, md_pages_reserved, md_file_path */
-    init_vfd_swmr_config(&config, 4, 7, writer, s.flush_raw_data, 128, "./dsetops-shadow");
+    /* 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);
 
     /* 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 16b1d4b..1c549ca 100644
--- a/test/vfd_swmr_generator.c
+++ b/test/vfd_swmr_generator.c
@@ -125,8 +125,9 @@ 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, flush_raw_data, md_pages_reserved, md_file_path */
-        init_vfd_swmr_config(config, 4, 10, vfd_swmr_write, TRUE, 128, "generator-shadow");
+        /* 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);
     }
 
     /* 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 430ed89..2be58e2 100644
--- a/test/vfd_swmr_gfail_writer.c
+++ b/test/vfd_swmr_gfail_writer.c
@@ -544,8 +544,9 @@ main(int argc, char **argv)
         TEST_ERROR;
     }
 
-    /* config, tick_len, max_lag, writer, flush_raw_data, md_pages_reserved, md_file_path */
-    init_vfd_swmr_config(&config, s.tick_len, s.max_lag, writer, TRUE, 128, "./group-shadow");
+    /* 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);
 
     /* 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 3342b40..18f3199 100644
--- a/test/vfd_swmr_gperf_writer.c
+++ b/test/vfd_swmr_gperf_writer.c
@@ -2786,8 +2786,9 @@ main(int argc, char **argv)
         return EXIT_SUCCESS;
     }
 
-    /* config, tick_len, max_lag, writer, flush_raw_data, md_pages_reserved, md_file_path */
-    init_vfd_swmr_config(&config, s.tick_len, s.max_lag, writer, FALSE, 128, "./group-shadow");
+     /* 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);
 
     /* 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 5881300..af46f3d 100644
--- a/test/vfd_swmr_group_writer.c
+++ b/test/vfd_swmr_group_writer.c
@@ -5011,8 +5011,9 @@ main(int argc, char **argv)
         TEST_ERROR;
     }
 
-    /* config, tick_len, max_lag, writer, flush_raw_data, md_pages_reserved, md_file_path */
-    init_vfd_swmr_config(&config, s.tick_len, s.max_lag, writer, TRUE, 128, "./group-shadow");
+    /* 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);
 
     /* 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_reader.c b/test/vfd_swmr_reader.c
index 6265cae..2b960c13 100644
--- a/test/vfd_swmr_reader.c
+++ b/test/vfd_swmr_reader.c
@@ -319,8 +319,9 @@ read_records(const char *filename, hbool_t verbose, FILE *verbose_file, unsigned
         goto error;
     }
 
-    /* config, tick_len, max_lag, writer, flush_raw_data, md_pages_reserved, md_file_path */
-    init_vfd_swmr_config(config, 4, 5, FALSE, TRUE, 128, "./rw-shadow");
+     /* 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);
 
     /* 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 4389b05..18dbb62 100644
--- a/test/vfd_swmr_remove_reader.c
+++ b/test/vfd_swmr_remove_reader.c
@@ -303,8 +303,9 @@ 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, flush_raw_data, md_pages_reserved, md_file_path */
-    init_vfd_swmr_config(config, 4, 5, FALSE, TRUE, 128, "./rw-shadow");
+     /* 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);
 
     /* 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 8df8fa8..41c2300 100644
--- a/test/vfd_swmr_remove_writer.c
+++ b/test/vfd_swmr_remove_writer.c
@@ -86,8 +86,9 @@ 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, flush_raw_data, md_pages_reserved, md_file_path */
-    init_vfd_swmr_config(config, 4, 5, TRUE, TRUE, 128, "./rw-shadow");
+     /* 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);
 
     /* 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 943c375..a737f70 100644
--- a/test/vfd_swmr_sparse_reader.c
+++ b/test/vfd_swmr_sparse_reader.c
@@ -207,8 +207,9 @@ 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, flush_raw_data, md_pages_reserved, md_file_path */
-    init_vfd_swmr_config(config, 4, 5, FALSE, TRUE, 128, "./rw-shadow");
+     /* 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);
 
     /* 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 56d19f3..f473249 100644
--- a/test/vfd_swmr_sparse_writer.c
+++ b/test/vfd_swmr_sparse_writer.c
@@ -86,8 +86,9 @@ 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, flush_raw_data, md_pages_reserved, md_file_path */
-    init_vfd_swmr_config(config, 4, 5, TRUE, TRUE, 128, "./rw-shadow");
+     /* 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);
 
     /* 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 fa9d7b4..2554207 100644
--- a/test/vfd_swmr_vlstr_reader.c
+++ b/test/vfd_swmr_vlstr_reader.c
@@ -115,8 +115,9 @@ main(int argc, char **argv)
     if (argc > 0)
         errx(EXIT_FAILURE, "unexpected command-line arguments");
 
-    /* config, tick_len, max_lag, writer, flush_raw_data, md_pages_reserved, md_file_path */
-    init_vfd_swmr_config(&config, 4, 7, false, TRUE, 128, "./vlstr-shadow");
+    /* 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);
 
     /* 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 4f7376e..e3905e8 100644
--- a/test/vfd_swmr_vlstr_writer.c
+++ b/test/vfd_swmr_vlstr_writer.c
@@ -184,8 +184,9 @@ main(int argc, char **argv)
     if (argc > 0)
         errx(EXIT_FAILURE, "unexpected command-line arguments");
 
-    /* config, tick_len, max_lag, writer, flush_raw_data, md_pages_reserved, md_file_path */
-    init_vfd_swmr_config(&config, 4, 7, true, TRUE, 128, "./vlstr-shadow");
+    /* 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);
 
     /* 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 4693554..0fb5fe8 100644
--- a/test/vfd_swmr_writer.c
+++ b/test/vfd_swmr_writer.c
@@ -88,8 +88,9 @@ 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, flush_raw_data, md_pages_reserved, md_file_path */
-    init_vfd_swmr_config(config, 4, 5, TRUE, TRUE, 128, "./rw-shadow");
+     /* 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);
 
     /* 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 13794d9..d40f2d9 100644
--- a/test/vfd_swmr_zoo_writer.c
+++ b/test/vfd_swmr_zoo_writer.c
@@ -473,8 +473,9 @@ main(int argc, char **argv)
 
     parse_command_line_options(argc, argv);
 
-    /* config, tick_len, max_lag, writer, flush_raw_data, md_pages_reserved, md_file_path */
-    init_vfd_swmr_config(&vfd_swmr_config, TICK_LEN, 7, writer, TRUE, 128, "./zoo-shadow");
+    /* 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);
 
     /* ? 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 */