HP StorageWorks XP Remote Web Console Software User Manual
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accessible. The reverse copy operation can only be performed on split pairs, not on suspended
pairs.
•
Quick Restore: The quick restore operation speeds up the reverse copy operation by changing the
volume map in the storage system to swap the contents of the S-VOL and T-VOL without copying
the T-VOL data to the S-VOL. The S-VOL and T-VOL are re-synchronized when update copy
operations are performed for pairs in the duplex status. The pair status during a quick restore
operation is resync-r until the volume map change is complete. The S-VOL and T-VOL become
inaccessible to all hosts for write operations during a quick restore operation.
lists the operational requirements for the quick restore operation.
CAUTION:
During the quick restore operation, the RAID levels, Cache Residency Manager for z/OS settings,
and HDD types of the S-VOL and T-VOL are exchanged. For example, if the S-VOL has a RAID-1
level and the T-VOL has a RAID-5 level, the quick restore operation changes the RAID level of the
S-VOL to RAID-5 and of the T-VOL to RAID-1. This also applies to RAID-6 volumes. To avoid any
performance impact due to the quick restore operation:
1.
Make sure that the S-VOL and T-VOL have the same RAID level and HDD type before performing
the quick restore operation. If you want to restore the original RAID levels after quick restore,
stop host I/Os to the pair, split the pair, perform the quick restore operation for that pair again,
and then restart the host I/Os to the pair.
2.
Because the Cache Residency Manager for z/OS settings are exchanged during a quick restore
operation, you must perform one of the two following operations. If you do not, the change
of location of the cache residence areas may cause I/O performance to the Cache Residency
Manager for z/OS data to be down:
• Set the same Cache Residency Manager for z/OS settings (locations) for the S-VOL and
T-VOL before performing the quick restore operation.
• Release the Cache Residency Manager for z/OS settings of the S-VOLs and T-VOLs before
the quick restore operation, and then reset the Cache Residency Manager for z/OS settings
of the S-VOLs and T-VOLs after the pair changes to
duplex
status as a result of the quick
restore operation.
CAUTION:
If you do not want the S-VOL and T-VOL to be re-synchronized after the quick restore operation,
you must set the Swap & Freeze option before performing the quick restore operation (see sections
and “
Setting Hitachi ShadowImage for z/OS Options
NOTE:
When a quick restore operation is in progress, the Remote Web Console window may display old
configuration information on components such as logical volumes (LDEVs); the window may display
configurations before the quick operation is performed. To update configuration information on the
Remote Web Console window, wait until the quick restore operation completes and then click the
Refresh button (
)
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Overview of Hitachi ShadowImage for z/OS Operations