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

    Binds up to three physical devices into a shadow set represented
    by the virtual unit named in the command. This qualifier is
    applicable only if you have the volume shadowing option. Refer
    to Volume Shadowing for OpenVMS for additional information.

    The format of this qualifier is:

    (virtual-unit-name[:] /SHADOW=(physical-device-name[:][,...]))

    This qualifier indicates that you are mounting a shadow set
    including the physical devices and the virtual unit that
    represents them to the system. This qualifier instructs MOUNT
    to expect a virtual unit name as the device-name parameter. Place
    the /SHADOW qualifier after the virtual-unit-name parameter.

    Use the virtual unit naming format DSAn, where n is a unique
    number from 0 to 9999. For the physical-device-name, use the
    standard device-naming format $allocation-class$ddcu[:].

    Examples

    The following example shows how to create a shadow set wherein
    the software determines automatically the correct copy operation
    for the two shadow set members. In this case, $1$DUA10 is the
    more current volume and becomes the source of the copy operation
    to $1$DUA11.

    $ MOUNT DSA0: /SHADOW=($1$DUA10:,$1$DUA11:) SHADOWVOL
    %MOUNT-I-MOUNTED, SHADOWVOL mounted on DSA0:
    %MOUNT-I-SHDWMEMSUCC, _$1$DUA10: (MEMBER1) is now a valid member of
    the shadow set
    %MOUNT-I-SHDWMEMCOPY, _$1$DUA11: (MEMBER2) added to the shadow set
    with a copy operation

    The following command creates a volume set with the logical name
    TEST3013. The volume set TEST3013 is shadowed, and each element
    of the shadowset (TEST3011 and TEST3012) is itself a volume set.

    $ MOUNT/BIND=TEST3013 DSA3011/SHADOW=($1$DUA402:,$1$DUA403:),
    DSA3012/SHADOW=($1$DUA404:,$1$DUA405:) TEST3011,TEST3012 TEST3013