HP P9000 for Compatible FlashCopy Mirroring User Guide (AV400-96388, October 2011)

Table 20 Types of Compatible FlashCopy options
FeaturesOption Type
FC Z Slower Copy1 option suppresses the background copy operations by
Compatible FlashCopy, and prioritizes the host I/O operations. For details, see
section “FC Z Slower Copy1 option” (page 35).
NOTE: You need to set FC Z Slower Copy2 option invalid.
FC Z Slower Copy1
FC Z Slower Copy2 option suppresses the background copy operations by
Compatible FlashCopy, and prioritizes the host I/O operations. You can suppress
FC Z Slower Copy2
more background copy operations of Compatible FlashCopy by using this option
than when you use FC Slower Copy1 option. For details, see “FC Slower Z
Copy2 Option” (page 35).
FC Z Slower Copy1 option
Use the FC Z Slower Copy1 option to improve host I/O responses for background copying
processing time of Compatible FlashCopy relationships. When the FC Slower Copy1 option is in
effect, the maximum number of Compatible FlashCopy relationships that can be copied
simultaneously in the background is halved, and consequently host I/O responses improve.
WARNING! If the FC Z Slower Copy2 option is in effect, FC Z Slower Copy1 option becomes
invalid.
When background copying processing of Compatible FlashCopy is suppressed by the FC Z 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 Z Copy2 Option
The FC Z Slower Copy2 option is used to improve host I/O responses over background copying
processing time of Compatible FlashCopy relationships. When the FC Z Slower Copy2 option is
in effect, the number of the Compatible FlashCopy relationships that can be copied simultaneously
in the background will be suppressed to one-quarter, and consequently host I/O responses improve.
The two options, FC Z Slower Copy1 and FC Z Slower Copy2, have the same function. The
difference between them is that FC Slower Copy2 allows improved host I/O responses because
it suppresses more background copy operations compared to the FC Slower Copy1 option.
WARNING! If the FC Z Slower Copy2 option is in effect, FC Z Slower Copy1 option becomes
invalid.
When background copying processing of Compatible FlashCopy is suppressed by the FC Z Slower
Copy2 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 will not necessarily quadruple.
If Business Copy pairs relationships exist in the same parity group, host I/O responses might not
be improved.
Selecting Prior operation 35