Hitachi MP-96RD625-01 manual Recovering a Pinned Track on a Data Volume

•Delete Mode: Allows you to specify whether to release the pair(s) forcibly. When the status of the pair(s) to be released is Simplex or Deleting, the default setting is Force. Otherwise, the default setting is Normal:

–Force: The pair(s) will forcibly be released even if the primary storage system is unable to communicate with the secondary storage system. This option may be used to free a host waiting for device-end from a primary storage system that cannot communicate with its the secondary storage system, thus allowing host operations to continue.

If you specify Force when the pair status is other than Simplex, Range will be set to Group.

–Normal: The pair(s) will be released only if the primary storage system is able to change the pair status of the primary and secondary data volumes to Simplex.

•Set: Applies the settings to the Preview list in the Pair Operation window (Figure 4-2).

•Cancel: Discards the settings.

Recovering a Pinned Track

If a hardware failure occurs when the storage system is in operation, some data in the cache memory of the storage system may not be written to disk drives and may remain in the cache memory. Data that remains in cache memory due to such a reason is referred to as "pinned track".

Recovering a Pinned Track on a Data Volume

If a pinned track occurs on a URz primary or secondary data volume, the primary storage system will suspend the data volume pair (SIM reference code

=D41x, D42x, DB1x, DB2x). Use the following procedure to ensure full data integrity of the data volume pair while recovering the pinned track:

1.Connect to the primary storage system and select the correct CU image.

2.Release the data volume pair that contains the volume with the pinned track.

3.If the volume is offline (e.g., secondary data volume has pinned track), vary the volume online.

4.Perform your usual procedure for recovering data from a pinned track. Refer to the pinned track recovery procedures for your operating system, or contact your Hitachi representative for assistance in recovering the pinned track.

5.If the volume was previously offline (e.g., secondary data volume. See step 3), make sure to vary the volume offline again.

8-28 Chapter 8 Performing Pair Operations

Hitachi Universal Replicator for IBM /OS User’s Guide