Closes a mounted disk or magnetic tape volume for further
   processing and cancels the logical name associated with the
   device.

   Requires the GRPNAM (group logical name) and SYSNAM (system
   logical name) privileges to dismount group and system volumes.

   Format

     DISMOUNT  device-name[:]

Additional information available:

QUALIFIERS

parameterExamples

device-name[:]
   Name of the device containing the volume-either a logical name or
   a physical name. If a physical name is specified, the controller
   defaults to A and the unit defaults to 0.

   If the volume currently mounted on the device is a member of a
   disk or tape volume set, all volumes in the set are dismounted,
   unless the /UNIT qualifier is specified.

Additional information available:

/ABORT/CLUSTER/OVERRIDE/UNIT/UNLOAD

   Requires volume ownership or the user privilege VOLPRO (volume
   protection) to use this qualifier with a volume that is mounted
   neither group nor system.

   Specifies that the volume is to be dismounted, regardless of who
   mounted it. The primary purpose of the /ABORT qualifier is to
   terminate mount verification. The DISMOUNT/ABORT command also
   cancels any outstanding I/O requests. If the volume was mounted
   with the /SHARE qualifier, the /ABORT qualifier causes the volume
   to be dismounted for all of the users who mounted it.

   Dismounts a volume clusterwide. If you specify DISMOUNT/CLUSTER,
   the DISMOUNT command checks for open files or other conditions
   that will prevent a Files-11 volume on the local node from
   dismounting. If the DISMOUNT command does not find any open
   files or other conditions, it checks for conditions on all other
   nodes in the cluster. If the DISMOUNT command finds one of the
   conditions on any node, it displays an error message identifying
   the device and the nodes on which the error occurred, followed by
   an error message indicating open files or other conditions on the
   volume.

   After the DISMOUNT command successfully dismounts the volume on
   the local node, it dismounts the volume on every other node in the
   existing VAXcluster environment. If the system is not a member of
   a cluster, the /CLUSTER qualifier has no effect.

      /OVERRIDE=CHECKS

   Marks a Files-11 volume for dismounting even if files are open
   on the volume. If you specify DISMOUNT/OVERRIDE=CHECKS, the
   DISMOUNT command displays messages indicating any open files or
   other conditions that prevent dismounting, immediately followed
   by a message indicating that the volume has been marked for
   dismounting.

   A substantial amount of time can pass between the time you enter
   the DISMOUNT/OVERRIDE=CHECKS command and the completion of the
   dismount operation. Always wait for the dismount to complete
   before you remove the volume. (To verify that the dismount has
   completed, enter the SHOW DEVICES command.) Note that the final
   phase of volume dismounting occurs in the file system, and all
   open files on the volume must be closed before the actual dismount
   can be done. Note, also, that the file system cannot dismount
   a volume while any known file lists associated with it contain
   entries.

   Dismounts only one volume of a volume set on the specified device.
   By default, all volumes in a set are dismounted.

                                  NOTE

      Avoid dismounting the root volume of a volume set, because
      it contains the master file directory (MFD). It may be
      impossible to access files on a volume set if the MFD is
      not accessible.

      /UNLOAD
      /NOUNLOAD

   Determines whether the device on which the volume is mounted is
   physically unloaded. If you specify the DISMOUNT command without
   the /UNLOAD or the /NOUNLOAD qualifier, the qualifier that you
   specified with the MOUNT command (either /UNLOAD or /NOUNLOAD)
   determines whether the volume is unloaded physically.

   1.  $ MOUNT MTA0: PAYVOL TAPE
          .
          .
          .
       $ DISMOUNT TAPE

     The MOUNT command in this example mounts the tape whose volume
     identification is PAYVOL on the device MTA0: and assigns the
     logical name TAPE to the device. By default, the volume is not
     shareable. The DISMOUNT command releases access to the volume,
     deallocates the device, and deletes the logical name TAPE.

   2.  $ MOUNT/SHARE DBA3:  DOC_FILES
          .
          .
          .
       $ DISMOUNT DBA3:

     The MOUNT command in this example mounts the volume labeled
     DOC_FILES on the device DBA3. Other users can enter MOUNT
     commands to access the device. The DISMOUNT command shown in
     this example deaccesses the device for the process issuing the
     command. If other users still have access to the volume, the
     volume remains mounted for their process or processes.


   3.  $ DISMOUNT/NOUNLOAD  DMA2:

     The DISMOUNT command in this example dismounts the volume; the
     /NOUNLOAD qualifier requests that the volume remain in a ready
     state.

   4.  $ MOUNT/BIND=PAYROLL  DMA1:,DMA2:  PAYROLL01,PAYROLL02
          .
          .
          .
       $ DISMOUNT/UNIT  DMA2:

     The MOUNT command in this example mounts PAYROLL, a two-
     volume set. The DISMOUNT command dismounts only PAYROLL02,
     leaving PAYROLL01 accessible. Note that because the master file
     directory (MFD) for the volume set is on the root volume, you
     should not dismount the root volume (in this case, PAYROLL01)
     of the volume set.


   5.  $ DISMOUNT $10$DJA100
       %DISM-W-CANNOTDMT, $10$DJA100: cannot be dismounted
       %DISM-W-INSWPGFIL, 4 swap or page files installed on volume
       %DISM-W-SPOOLEDEV, 3 devices spooled to volume
       %DISM-W-INSTIMAGE, 7 images installed on volume
       %DISM-W-USERFILES, 6 user files open on volume

     The DISMOUNT command in this example displays the open files
     and other conditions that prevent device $10$DJA100 from
     dismounting.

   6.  $ DISMOUNT/CLUSTER $10$DJA100
       %DISM-W-RMTDMTFAIL, $10$DJA100: failed to dismount on node SALT
       %DISM-W-FILESOPEN, volume has files open on remote node
       %DISM-W-RMTDMTFAIL, $10$DJA100: failed to dismount on node PEPPER
       %DISM-W-FILESOPEN, volume has files open on remote node
       %DISM-W-CANNOTDMT, $10$DJA100: cannot be dismounted

     The DISMOUNT command in this example displays messages
     identifying device $10$DJA100 and nodes SALT and PEPPER on
     which errors occurred followed by messages indicating open
     files on the volume.