o  This command is only valid on a disk device that is not
       mounted. If the device is mounted, an error occurs and the
       process will abort. This command cannot work on the system
       disk because it is always mounted.

    o  For a bound volume set, this utility only works on the "ROOT"
       volume.

    o  For disk volumes in a shadow set (single member or otherwise),
       the following restrictions apply:

       o  Do not specify the virtual unit name to defragment (for
          example: DSAnnnn:).

       o  Specify only one physical device name (for example:
          $1$DUAnnnn:).

       o  Use the following procedure to defragment INDEXF.SYS in a
          shadow set:

          1. Dismount both members of the shadow set.

          2. Mount one of the physical disk volumes with
             /OVERRIDE=SHADOW and then dismount it before doing the
             defragmentation. If you do not do this, you will receive
             the following error:

             %SYSTEM-F-WRITLCK, write lock error

          3. Defragment the INDEXF.SYS on the disk volume.

          4. Mount the disk volume into the shadow set.

          5. Add the disk volume that was not defragmented into the
             shadow set. Mounting this disk volume causes a full copy
             operation.

       o  If you experience a power failure during the
          defragmentation of INDEXF.SYS, you may need to do the
          following:

          -  Repair alternate index file header and index file bitmap
             by doing a ANALYZE/DISK/REPAIR.

          -  Delete disk:[000000]DFG$DEFRAG_INDEXF.DAT.