System Options - HP StorageWorks P9000 User Manual

For copy pace, specify Slower when you create, split, or resynchronize.
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When you need to perform a copy operation on multiple pairs on the same parity group,
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perform the operation on one pair at a time.
If the system is overloaded, increase parity groups, cache, and/or DKAs. Assign S-VOLs
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to newly installed parity groups.
When using multiple program products simultaneously. If you are using more than program
product at the same time, ensure that your storage system is configured for optimal performance
(for example, sufficient cache). Contact HP Technical Support. Concurrent use affects the
performance and the operation of the other program products.
When using AIX host servers. Best performance results when P-VOLs are located on one AIX
host server and paired S-VOLs on another. The problem with using one AIX host server for
both P-VOLs and S-VOLs is that during the paircreate or pairresync operation, the P-VOL and
S-VOL have the same PVID. If the host server reboots when this is the case, it can mis-identify
the volumes and identify the S-VOL as the P-VOL after rebooting.
Preparing for resynchronization by Quick Restore. During a quick restore operation, in which
the contents of the P-VOL and S-VOL are swapped, the RAID levels, HDD types, and Cache
Residency settings of the two volumes are also exchanged. To avoid performance impact,
consider the following:
◦ Both pair volumes should have the same RAID level and HDD type before performing the
quick restore operation. You can resume the original RAID levels after the quick restore
by again splitting the pair and performing the quick restore.
◦ Set the same Cache Residency settings (locations) for the P-VOL and S-VOL before the
quick restore operation.
Alternatively, you can release Cache Residency settings before the quick restore operation,
then reset them when the operation is completed.
See the HP StorageWorks P9000 Performance for Open and Mainframe Systems User
Guide for more information on settings.
CAUTION:
and S-VOL are in different CLPRs. If you perform Quick Restore, the CLPR of the P-VOL and
the CLPR of the S-VOL will be reversed after Quick Restore.

System options

Business Copy provides the following options. To enable Copy Threshold option, call your service
representative. Swap&Freeze and Host I/O Performance option can be set by using Remote Web
Console.
Swap&Freeze. This option alters the behavior of the quick restore operation. With
Swap&Freeze, update copy operations are suppressed when the quick restore is completed
and the pair is in PAIR status. Differential data is not copied to the new S-VOL. You use the
Swap&Freeze option, when you want to remain the S-VOLs of a Business Copy pair unchanged
after the quick restore operation.
Host I/O Performance. This option increases I/O performance while suppressing Business
Copy copy processing. This results in longer copy time.
Copy Threshold. This option temporarily stops copy operations when the workload on the
storage system is heavy. This is done to minimize degradation to host I/O performance during
peak periods.
16 Requirements and planning
It is recommended that Quick Restore should not be performed when the P-VOL