Index: b/lustre/utils/mount_lustre.c
===================================================================
--- a/lustre/utils/mount_lustre.c
+++ b/lustre/utils/mount_lustre.c
@@ -484,10 +484,39 @@ set_params:
                 snprintf(real_path, sizeof(real_path), "%s/%s", path,
                          MAX_SECTORS_KB_PATH);
                 rc = write_file(real_path, buf);
-                if (rc && verbose)
-                        fprintf(stderr, "warning: writing to %s: %s\n",
-                                real_path, strerror(errno));
+                if (rc) {
+                        if (verbose)
+                                fprintf(stderr, "warning: writing to %s: %s\n",
+                                        real_path, strerror(errno));
+                        return rc;
+                }
+        }
+
+        /* if device is multipath device, tune its slave devices */
+        snprintf(real_path, sizeof(real_path), "%s/slaves/*", path);
+        rc = glob(real_path, GLOB_NOSORT, NULL, &glob_info);
+        if (rc == GLOB_NOMATCH) {
+            /* no slave device is not an error */
+            rc = 0;
         }
+        if (rc) {
+                if (verbose)
+                        fprintf(stderr, "warning: %s. "
+                                "failed to read entries under %s/slaves\n",
+                                strerror(errno), path);
+                return rc;
+        }
+
+        for (i = 0; i < glob_info.gl_pathc; i++){
+                char *slave;
+                slave = basename(glob_info.gl_pathv[i]);
+                snprintf(real_path, sizeof(real_path), "/dev/%s", slave);
+                rc = set_blockdev_tunables(real_path);
+                if (rc)
+                        break;
+        }
+        globfree(&glob_info);
+
         return rc;
 }