HP XP P9500 Storage - Manual (Page 38)

Related information
•
“Removing reserve attribute from a volume” (page 59)
System options that affect performance
You can enable and disable the following options that affect performance. (To go directly to the
procedure, see
“Setting performance options” (page 39) ).
•
Swap&Freeze. 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. Use the Swap&Freeze option when
you want to keep S-VOLs unchanged after the quick restore operation.
•
Host I/O Performance. Increases I/O performance while suppressing copy processing.
However, be aware that enabling this option results in a longer copy time, slowing copy
processing.
•
Copy Threshold. 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.
The option performs only when workload is heavy; the Host I/O Performance option suppresses
copy operations at all times regardless of workload level.
When the Copy Threshold Option is enabled, it is effective for all of the following software:
◦ BC
◦ BC Z
◦ Compatible FlashCopy
◦ FS
◦ SS
◦ Auto LUN
NOTE: Your service representative must enable the Copy Threshold option.
•
Copy Pace options. Reduce the effect on host server I/O performance by suppressing copy
processing in PAIR status. The system uses this option when pairs are in PAIR status only. This
option does not have an effect if the pair is in other statuses.
You can choose from three levels of processing-suppression/performance-improvement:
◦ Copy Pace Ext. None (usable since program version 70-03-01-xx/xx). This is the most
effective option—stops copy processing.
NOTE: With this option, synchronization when a pair is split tends to be slower, which
prolongs the time that the pair is in process of Quick Split (PSUS(SP)/PSUS status) or in
the process of Steady Split (COPY(SP)/COPY status). If this poses a problem, complete
one of the following:
– Minimize the time that the pair is in PAIR status so that synchronization at the pair
split does not require so much time.
– Use one of the other Copy Pace options.
◦ Copy Pace Ext. Slower2—2nd most effective
◦ Copy Pace Ext. Slower1—3rd most effective
38 Performing configuration operations