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

       /SHARE
       /NOSHARE

    Specifies, for a disk volume, that the volume is shareable.

    If another user has already mounted the volume shareable, and
    you request it to be mounted with the /SHARE qualifier, any other
    qualifiers you enter are ignored.

    By default, a volume is not shareable, and the MOUNT command
    allocates the device on which it is mounted.

    If you previously allocated the device and specify the /SHARE
    qualifier, the MOUNT command deallocates the device so that other
    users can access it.

    The /SHARE qualifier is incompatible with the /GROUP and /SYSTEM
    qualifiers.

    Example

    The following command mounts the device labeled SLIP on DLA0,
    disables broadcasting of MOUNT messages, specifies that the
    volume is shareable, and assigns the logical name DISC:

    $ MOUNT/NOMESSAGE/SHARE DLA0: SLIP DISC