diff --git a/src/rest_vol.h b/src/rest_vol.h
index f5b19e9d..1b6391cd 100644
--- a/src/rest_vol.h
+++ b/src/rest_vol.h
@@ -725,9 +725,12 @@ herr_t RV_curl_multi_perform(CURL *curl_multi_ptr, dataset_transfer_info *transf
     (version.major > major_needed) || (version.major == major_needed && version.minor > minor_needed) ||     \
         (version.major == major_needed && version.minor == minor_needed && version.patch >= patch_needed)
 
-#define SERVER_VERISON_SUPPORTS_FILL_VALUE_ENCODING(version)                                                 \
+#define SERVER_VERSION_SUPPORTS_FILL_VALUE_ENCODING(version)                                                 \
     (SERVER_VERSION_MATCHES_OR_EXCEEDS(version, 0, 8, 1))
 
+#define SERVER_VERSION_SUPPORTS_GET_STORAGE_SIZE(version)                                                    \
+    (SERVER_VERSION_MATCHES_OR_EXCEEDS(version, 0, 8, 5))
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/rest_vol_dataset.c b/src/rest_vol_dataset.c
index de977f17..e5007779 100644
--- a/src/rest_vol_dataset.c
+++ b/src/rest_vol_dataset.c
@@ -1232,9 +1232,10 @@ RV_dataset_get(void *obj, H5VL_dataset_get_args_t *args, hid_t dxpl_id, void **r
     RV_object_t *dset      = (RV_object_t *)obj;
     herr_t       ret_value = SUCCEED;
 
-    size_t host_header_len = 0;
-    char  *host_header     = NULL;
-    char   request_url[URL_MAX_LENGTH];
+    H5VL_file_specific_args_t vol_flush_args;
+    size_t                    host_header_len = 0;
+    char                     *host_header     = NULL;
+    char                      request_url[URL_MAX_LENGTH];
 
 #ifdef RV_CONNECTOR_DEBUG
     printf("-> Received dataset get call with following parameters:\n");
@@ -1286,6 +1287,18 @@ RV_dataset_get(void *obj, H5VL_dataset_get_args_t *args, hid_t dxpl_id, void **r
         /* H5Dget_storage_size */
         case H5VL_DATASET_GET_STORAGE_SIZE:
 
+            if (!(SERVER_VERSION_SUPPORTS_GET_STORAGE_SIZE(dset->domain->u.file.server_version)))
+                FUNC_GOTO_ERROR(H5E_DATASET, H5E_UNSUPPORTED, FAIL,
+                                "H5Dget_storage_size requires HSDS 0.8.5 or higher");
+
+            /* First, flush domain to make server update allocated bytes */
+            vol_flush_args.op_type             = H5VL_FILE_FLUSH;
+            vol_flush_args.args.flush.obj_type = H5I_FILE;
+            vol_flush_args.args.flush.scope    = H5F_SCOPE_LOCAL;
+
+            if (RV_file_specific((void *)dset->domain, &vol_flush_args, H5P_DEFAULT, NULL) < 0)
+                FUNC_GOTO_ERROR(H5E_DATASET, H5E_CANTFLUSH, FAIL, "can't flush datase's domain");
+
             /* Make GET request to dataset with 'verbose' parameter for HSDS. */
             snprintf(request_url, URL_MAX_LENGTH, "%s%s%s%s", base_URL, "/datasets/", dset->URI,
                      "?verbose=1");
@@ -2407,7 +2420,7 @@ RV_convert_dataset_creation_properties_to_JSON(hid_t dcpl, char **creation_prope
                 out_string_curr_pos += null_value_len;
             }
             else if (H5D_FILL_VALUE_USER_DEFINED == fill_status) {
-                if (!(SERVER_VERISON_SUPPORTS_FILL_VALUE_ENCODING(version)))
+                if (!(SERVER_VERSION_SUPPORTS_FILL_VALUE_ENCODING(version)))
                     FUNC_GOTO_ERROR(H5E_DATASET, H5E_UNSUPPORTED, FAIL,
                                     "server API version %zu.%zu.%zu does not support fill value encoding\n",
                                     version.major, version.minor, version.patch);
diff --git a/src/rest_vol_file.c b/src/rest_vol_file.c
index 59b11ada..0707fede 100644
--- a/src/rest_vol_file.c
+++ b/src/rest_vol_file.c
@@ -659,7 +659,7 @@ RV_file_specific(void *obj, H5VL_file_specific_args_t *args, hid_t dxpl_id, void
              * the containing domain. */
             RV_object_t *target_domain = file->domain;
             filename                   = target_domain->u.file.filepath_name;
-            const char *flush_string   = "/?flush=1";
+            const char *flush_string   = "/?flush=1&rescan=1";
 
             name_length = strlen(filename);