HP XP P9500 Storage - Manual (Page 40)

Selecting Prior operation
You can use the options in the following table for Compatible FlashCopy V2 and Compatible
FlashCopy SE operations. The available option types depend on the storage system settings.
Table 23 Types of Compatible FlashCopy V2 and Compatible FlashCopy SE options
Features Option type
Suppresses the background copy operations by Compatible FlashCopy, and prioritizes the
host I/O operations. For details, see topic
“FC Slower Copy1 option” (page 40) .
FC Slower Copy1
Note: You need to set FC Slower Copy2 option invalid.
Suppresses the background copy operations by Compatible FlashCopy, and prioritizes the
host I/O operations. You can suppress more Compatible FlashCopy background copy FC Slower Copy2
operations by using this option instead of the FC Slower Copy1 option. For details, see “FC
Slower Copy2 Option” (page 40) .
Suppresses the background copy operations by Compatible FlashCopy, and prioritizes the
host I/O operations. For details, see
“FC Ext. Slower Copy1 Option” (page 41) .
FC Ext. Slower Copy1
Note: You need to set FC Ext. Slower Copy1 option invalid.
Suppresses the background copy operations by Compatible FlashCopy, and prioritizes the
host I/O operations. You can suppress more Compatible FlashCopy background copy FC Ext. Slower Copy2
operations by using this option instead of the FC Ext. Slower Copy1 option. For details, see
“FC Ext. Slower Copy2 Option” (page 41) .
FC Slower Copy1 option
The FC Slower Copy1 option is used to prioritize host I/O response over background copying
processing of Compatible FlashCopy relationships. When the FC Slower Copy1 option is in effect,
the maximum number of the Compatible FlashCopy relationships that can be copied simultaneously
in the background is halved, and consequently host I/O response improves.
CAUTION: If the FC Slower Copy2 option is in effect, the FC Slower Copy1 option becomes
invalid.
When background copying processing of Compatible FlashCopy is suppressed by the FC Slower
Copy1 option, the time taken for background copying increases. However, since the background
copying processing time of relationships is not always same, the background copying processing
time is not necessarily doubled.
If Business Copy pairs exist in the same parity group, host I/O responses might not be improved.
FC Slower Copy2 Option
The FC Slower Copy2 option is used to prioritize host I/O response over background copying
processing of Compatible FlashCopy relationships. When the FC Slower Copy2 option is in effect,
the number of Compatible FlashCopy relationships that can be copied simultaneously in the
background is suppressed to one-quarter, and consequently host I/O response improves.
The two options, FC Slower Copy1 and FC Slower Copy2, have the same function. The difference
between them is that FC Slower Copy2 provides the best host I/O response because it suppresses
more background copy operations than the FC Slower Copy1 option.
CAUTION: When the FC Slower Copy2 option is in effect, the FC Slower Copy1 option becomes
invalid.
When background copy processing of Compatible FlashCopy is suppressed by the FC Slower
Copy2 option, the time taken for background copying increases. However, since the background
copy processing time of relationships is not always same, the background copy processing time
does not necessarily quadruple.
40 Preparing for Compatible FlashCopy operations