HP StorageWorks XP Remote Web Console Software - Manual (Page 39)

Quick Restore Operation
S-VOL T-VOL
Split
S-VOL T-VOL
Duplex
S-VOL T-VOL
Duplex
With Swap&Freeze Option
S-VOL T-VOL
Duplex
Without Swap&Freeze Option
Legend
: Time flow
: User Data
Figure 14 Quick Restore Operation with or without Swap & Freeze Option
The Quick Restore pairresync operation is used on a pair where the status is split and exchanges data
in the S-VOL and the T-VOL of that pair. If you use Swap & Freeze option when performing the Quick
Restore pairresync operation, the update copy operation does not take place after the Quick Restore
pairresync operation is complete. The data of the S-VOL and the T-VOL is therefore kept exchanged.
If you do not use Swap & Freeze option when performing the Quick Restore pairresync operation, the
update copy operation takes place after the Quick Restore pairresync operation is complete, and the
data in the S-VOL overwrites the data in the T-VOL.
Host I/O Performance Option
The Host I/O Performance option improves host I/O responses over Siz copying processing time. When
the Host I/O Performance option is used, the storage system suppresses execution of Siz copying
processing, and consequently the host I/O responses improve.
NOTE:
When Siz copying processing is suppressed by the Host I/O Performance option, the time taken for
copying increases. If Siz pairs exist, host I/O responses might not be faster. In this case, set the Host
I/O Performance option for Siz as well.
FCv2 Slower Copy1 Option
The FCv2 Slower Copy1 option is used to improve host I/O responses over copying processing time
of FlashCopy Mirror V2 pairs. When the FCv2 Slower Copy1 option is in effect, the number of the
FlashCopy Mirror V2 pairs that can be copied simultaneously is suppressed to half, and consequently
host I/O responses improve.
Hitachi ShadowImage for z/OS user guide 39