Backing up a mirrored set

All users of the volume set must initially be logged off before a split-volume backup can be performed. Notify users of the volume set that they need to log off.

	NOTE: If you do not want to log off the system, make sure that you are not logged on to the mirrored volume set that you want to back up. You can use the CHGROUP command to switch to another volume set.

   :TELL @ LOGOFF FOR BACKUP

Use the VSCLOSE command with the SPLIT option to split the volume set into user volumes and backup volumes.

	NOTE: The VSCLOSE command with the SPLIT option can only proceed if the files in the volume set are not being accessed. The NOW option of the VSCLOSE command cannot be used with the SPLIT option.

You can use the DSTAT command to display the split-volume set.

   :VSCLOSE PROD_SET; SPLIT

   :DSTAT



   LDEV-TYPE  STATUS      VOLUME  (VOLUME SET - GEN) 

   _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

   30- 079370  LONER-SU    MEMBER1 (PROD_SET-0)

   31- 079370  LONER-SB    MEMBER1 (PROD_SET-0)

   32- 079370  LONER-SU    MEMBER2 (PROD_SET-0)

   33- 079370  LONER-SB    MEMBER2 (PROD_SET-0)

Data is unavailable from the time it that takes to complete the VSCLOSE and VSOPEN. Other than this interval, the files are continuously accessible to users.

Since the disks are in the LONER state after the VSCLOSE, either volume set half may be taken offline and used independently of the other half.

Use the VSOPEN command to make the volume set available. Both user volumes and backup volumes will attempt to be mounted.

	NOTE: If either of them has been taken offline, the command only mounts the available volume set half.

   :VSOPEN PROD_SET



   PROD_SET SPLIT USER VOLUME MOUNTED ON LDEV 32 

   (AVR 23)



   PROD_SET SPLIT BACKUP VOLUME MOUNTED ON LDEV 33 

   (AVR 24)

After the volume set is placed online using the VSOPEN command, it is mounted and available for use.

	NOTE: Once a volume set has been taken offline with a VSCLOSE command, it can only be mounted with a VSOPEN command, not by bringing it online.

Notify users that the volume set is available.

You can use the DSTAT command to display the user volumes (-SU) and the backup volumes (-SB).

   :TELL @ SYSTEM IS AVAILABLE NOW

   :DSTAT



   LDEV-TYPE  STATUS   VOLUME  (VOLUME SET - GEN) 

   _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

   30- 079370  MASTER-SU   MEMBER1 (PROD_SET-0)

   31- 079370  MASTER-SB   MEMBER1 (PROD_SET-0)

   32- 079370  MEMBER-SU   MEMBER2 (PROD_SET-0)

   33- 079370  MEMBER-SB   MEMBER2 (PROD_SET-0)

Use the FILE command to specify that a tape drive will be used as the output device.

Use the STORE command with SPLITVS to start storing the files. The SHOW option is used to display the files that have been stored to tape.

   :FILE T; DEV=TAPE

   :STORE @.@.@; T; SPLITVS=PROD_SET; SHOW

Use the new VOLUTIL command JOINMIRRSET to join the user and backup halves of a split volume set to make them mirrored again. After the volume set is joined, a repair starts using the volumes that were specified by the source parameter as the source volumes.

	NOTE: The SOURCE=USER option is specified so users can continue accessing the volume set while the join is initiated and the repair takes place.

   :VOLUTIL



   Mirvutil A.00.00, (C) Hewlett-Packard Co., 1990. 

   All Rights Reserved.



   volutil:JOINMIRRSET PROD_SET SOURCE=USER

Ideally, all members and partners should be present at the time of the join. If any of the volumes are unavailable (due to disk or other errors), some amount of recoverability can be done depending on the situation. Refer to the "Troubleshooting" chapter in this manual for more information.

Once the volume set has been rejoined a repair, starts to bring both pairs to a consistent state. You can use the SHOWSET command to display the disks being repaired.

   volutil:SHOWSET PROD_SET MIRROR



   Volume Name  Vol Status   Mirr Status  Ldev  Mirr ldev

   - - - - - -  - - - - - -  - - - - - - - - -  - - - - - 

   MEMBER1      MASTER       REPAIR-SRCE  30    31   

   MEMBER1      MASTER       REPAIR-DEST  31    30   

   MEMBER2      MEMBER       REPAIR-SRCE  32    33   

   MEMBER2      MEMBER       REPAIR-DEST  33    32   

	NOTE: A maximum of six mirrored pairs can be repaired simultaneously. If there are more than six mirrored pairs to be repaired, the repairs are staged. This means that when one of the six repairs finishes, another begins.