HP StorageWorks XP Remote Web Console Software - Manual (Page 28)

28 ShadowImage for the XP128/XP1024/XP10000/XP12000
When SI390 copying processing is suppressed by the Host I/O Performance option, the time taken for
copying increases. Also, if BC pairs exist, host I/O responses might not be faster. In this case, set the Host
I/O Performance option for BC 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 Version 2 pairs. When the FCv2 Slower Copy1 option is in effect, the number of the
FlashCopy Mirror Version 2 pairs that can be copied simultaneously will be suppressed to half, and
consequently host I/O responses improve.
CAUTION: If the FCv2 Slower Copy2 option is in effect, FCv2 Slower Copy1 option becomes invalid.
NOTE:
•
When copying processing of FlashCopy Mirror Version 2 is suppressed by the FCv2 Slower Copy1
option, the time taken for copying increases. However, since the copying processing time of pairs is not
always same, note that the copying processing time will not be necessarily doubled.
• If ShadowImage pairs or FlashCopy Mirror Version 2 pairs exist in the same parity group, host I/O
responses might not be improved.
Fcv2 Slower Copy2 Option
The FCv2 Slower Copy2 option is used to improve host I/O responses over copying processing time of
FlashCopy Mirror Version 2 pairs. When the FCv2 Slower Copy2 option is in effect, the number of the
FlashCopy Mirror Version 2 pairs that can be copied simultaneously will be suppressed to one-quarter,
and consequently host I/O responses improve.
The FCv2 Slower Copy2 option and the FCv2 Slower Copy1 option basically have same function. The
difference between these two options is that the you can more improve host I/O responses by using the
FCv2 Slower Copy2 option than by using the FCv2 Slower Copy1 option. This happens since the FCv2
Slower Copy2 option suppresses more copy operations compared to the FCv2 Slower Copy1 option.
CAUTION: If the FCv2 Slower Copy2 option is in effect, FCv2 Slower Copy1 option becomes invalid.
NOTE:
•
When copying processing of FlashCopy Mirror Version 2 is suppressed by the FCv2 Slower Copy2
option, the time taken for copying increases. However, since the copying processing time of pairs is not
always same, note that the copying processing time will not necessarily quadruple.
• If ShadowImage pairs or FlashCopy Mirror Version 2 pairs exist in the same parity group, host I/O
responses might not be improved.
At-Time Split Function
To use the At-Time Split function, you need Business Continuity Manager software. Business Continuity
Manager software is to be executed from a host server. To perform the split operation by using the At-Time
Split function, you must specify a copy group or register the split time in the copy group. The split time
indicates the time when you want to store the S-VOL data to the T-VOL.
For example, if you register the consistency group of ShadowImage for z/OS as the copy group of the
Business Continuity Manager, the At-Time Split function enables you to copy data from the SIz S-VOLs in
the same consistency group to T-VOLs simultaneously. The T-VOLs will contain the same data as the S-VOLs
when the Split operation is performed.