/sys$common/syshlp/helplib.hlb MOUNT, Qualifiers, /MULTI_VOLUME  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /MULTI_VOLUME
       /NOMULTI_VOLUME (default)

    For foreign or unlabeled magnetic tape volumes, determines
    whether you override MOUNT volume-access checks.

    Use /MULTI_VOLUME to override access checks on volumes that do
    not contain labels that MOUNT can interpret. If you have software
    produced before OpenVMS Version 5.0 that processes multiple-
    volume, foreign-mounted tape volumes without specifically
    mounting and dismounting each reel, you may now need to mount
    the first volume with the /MULTI_VOLUME qualifier.

    Use this qualifier when a utility that supports multiple-volume,
    foreign-mounted magnetic tape sets needs to process subsequent
    volumes, and these volumes do not contain labels that the OpenVMS
    Mount command can interpret.

    By default, all tape volumes are subject to the complete access
    checks of the OpenVMS Mount command (MOUNT). Some user-written
    and vendor-supplied utilities used prior to OpenVMS Version 5.0
    may mount only the first tape in a foreign tape set. To make
    these utilities compatible with more recent versions of OpenVMS,
    alter them to perform explicit calls to the $MOUNT and $DISMOU
    system services for each reel in the set. As an alternative,
    you can now mount the magnetic tape sets to be used by these
    utilities with the /MULTI_VOLUME qualifier.

    You must specify the /FOREIGN qualifier with the /MULTI_VOLUME
    qualifier and you must have the user privilege VOLPRO. The
    default is /NOMULTI_VOLUME.

                                   NOTE

       The OpenVMS Backup utility (BACKUP) explicitly calls
       the $MOUNT and $DISMOU system services on each reel of
       a foreign-mounted magnetic tape set. For additional
       information, Refer to the section on multivolume save
       sets and BACKUP in the OpenVMS System Management Utilities
       Reference Manual: A-L.

    Example

    The following command mounts a tape volume set. MOUNT performs an
    access check on the first volume in the set and proceeds without
    checks to subsequent reels as they are needed for processing.

    $ MOUNT/FOREIGN/MULTI_VOLUME MUA0: