HP XP P9500 Storage - Manual (Page 14)

•
If the S-VOL capacity exceeds the T-VOL capacity in the relationship being reversed.
•
If the original relationship was reestablished using the Fast Reverse Restore function.
For details about Fast Reverse Restore function, see “Fast Reverse Restore function” (page 14) .
You can judge whether the Reverse Restore function can be used by examining the results of the
FLASHCOPY QUERY RELATIONS command of ICKDSF. For details, see
“Displaying information
about Compatible FlashCopy pairs: FLASHCPY QUERY RELATIONS” (page 71) .
When you perform the Reverse Restore function, only the updated data is copied from newly
specified S-VOL to T-VOL.
The following figure shows the workflow that occurs from establishing the Compatible FlashCopy
relationship by the Incremental FlashCopy function to the executing of the update copy operation
(Reverse Restore).
Figure 8 Performing Reverse Restore
Fast Reverse Restore function
The Fast Reverse Restore function enables you to simplify data recovery in a time of disaster. This
recovery function reverses the original S-VOL and T-VOL relationship established by the Compatible
FlashCopy relationships function. This reversal reestablishes the relationship with the data flowing
in the opposite direction. However, you cannot perform the Fast Reverse Restore function in the
following cases.
•
If the relationships to be reversed include a relationship established with multiple volumes.
•
If the S-VOL capacity exceeds the T-VOL capacity in the relationship to be reversed.
•
If the original relationship was reestablished using the Fast Reverse Restore function.
You can perform the Fast Reverse Restore function on a relationship established in NOCOPY mode
or on a relationship undergoing copy process. If you perform the Fast Reverse Restore function
undergoing copy process, the copy process will end at that time.
14 About Compatible FlashCopy operations