VMS Help SET, FILE, /RU_JOURNAL, Parameters  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 volume-name

    Specifies the volume on which the recovery unit journals will be
    located, using one of the following keywords:

    o  DEVICE=device_name specifies a device name or logical name.

    o  LABEL=volume-label specifies a volume label.

    By default, recovery unit journals are created temporarily in the
    [SYSJNL] directory on the same volume as the file that is being
    journaled. (If such a directory does not exist, RMS journaling
    creates it automatically.) You can change the device on which the
    recovery unit journals are created by using either the DEVICE or
    LABEL keyword.

    Use the DEVICE keyword to specify the location of recovery unit
    journals using a device name or a logical name. Use the LABEL
    keyword to specify the location of recovery unit journals using a
    volume label. You can only use one of these two keywords (LABEL
    or DEVICE) to specify the recovery unit journal location. In
    either case, only the volume label is actually stored with the
    file.

    At run time, RMS attempts to translate the logical name
    DISK$volume_label when creating a recovery unit journal. This
    is the default logical name created by the Mount Utility when you
    mount the disk using the /SYSTEM or /CLUSTER qualifier. If you do
    not mount the disk using the /SYSTEM or /CLUSTER qualifier, you
    must define the logical name DISK$volume_label using the DEFINE
    command with the /SYSTEM and /EXECUTIVE_MODE qualifiers. You
    must have the SYSNAM (system logical name) or the SYSPRV (system
    privilege) privilege to use the /SYSTEM qualifier.

                                   NOTE

       The logical name DISK$volume_label can point to any
       disk device on the system that is mounted and has for
       its volume label an executive-mode logical name in the
       form DISK$volume_label with the concealed and terminal
       attributes.

 data-filespec[,...]

    Specifies the file that is to be marked for recovery unit
    journaling. If a data file has been marked for recovery unit
    journaling with this command, DECdtm transaction services
    ($START_TRANS, $END_TRANS, and $ABORT_TRANS) must be used by
    an application program to define transactions whenever data in
    this file is modified.

    If you specify more than one file, separate the file
    specifications with commas. The asterisk (*) and the percent
    sign (%) wildcard characters are allowed. The file specification
    cannot include a node name, since the SET FILE command is not
    valid for network access.