VMS Help MOUNT, Qualifiers, /CLUSTER  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Specifies that after the volume is successfully mounted on the
    local node, or if it is already mounted /SYSTEM on the local
    node, it is to be mounted on every other node in the existing
    VMScluster (that is, the volume is mounted clusterwide).

    Only system or group volumes can be mounted clusterwide. If
    you specify the /CLUSTER qualifier with neither the /SYSTEM
    nor the /GROUP qualifier, the default is /SYSTEM. Note that
    you must use a cluster device-naming convention. Use either
    node$device-name or allocation-class$device-name as required
    by your configuration.

    You need the user privileges GRPNAM and SYSNAM, respectively, to
    mount group and system volumes clusterwide.

    If the system is not a member of an OpenVMS Cluster, the /CLUSTER
    qualifier has no effect.

    Example

    The following MOUNT/CLUSTER command mounts the volume SNOWWHITE
    on DOPEY$DMA1, then proceeds to mount the volume clusterwide. The
    SHOW DEVICE/FULL command displays information about the volume,
    including the other nodes on which it is mounted.

    $ MOUNT/CLUSTER DOPEY$DMA1: SNOWWHITE DWARFDISK
    %MOUNT-I-MOUNTED, SNOWWHITE         mounted on _DOPEY$DMA1:
    $ SHOW DEVICE/FULL DWARFDISK:

    Disk $2$DMA1: (DOPEY), device type RK07, is online, mounted,
        file-oriented device, shareable, served to cluster via MSCP
        Server, error logging is enabled.

        Error count                0  Operations completed                159
        Owner process             ""  Owner UIC                      [928,49]
        Owner process ID    00000000  Dev Prot         S:RWED,O:RWED,G:RW,W:R
        Reference count            1  Default buffer size                 512
        Total blocks           53790  Sectors per track                    22
        Total cylinders          815  Tracks per cylinder                   3
        Allocation class           2

        Volume label     "SNOWWHITE"  Relative volume number                0
        Cluster size               3  Transaction count                     1
        Free blocks            51720  Maximum files allowed              6723
        Extend quantity            5  Mount count                           7
        Mount status          System  Cache name      "_$255$DWARF1:XQPCACHE"
        Extent cache size         64  Maximum blocks in extent cache     5172
        File ID cache siz         64  Blocks currently in extent cache      0
        Quota cache size          25  Maximum buffers in FCP cache        349

      Volume status: ODS-2, subject to mount verification,
         file high-water marking, write-through caching enabled.
      Volume is also mounted on DOC, HAPPY, GRUMPY, SLEEPY, SNEEZY, BASHFUL.