The Reverse Restore function enables you to simplify data recovery. This function reverses the original S-VOL and T-VOL relationship established by the Incremental FlashCopy® function. This reversal re-establishes the relationship with the data flowing in the opposite direction.
You cannot perform the Reverse Restore function in the following cases:
- The original relationship was established without using the Incremental FlashCopy® function.
- A copy operation established in COPY mode is not yet completed.
- The original relationship was established in NOCOPY mode.
- The relationship being reversed includes a relationship established with multiple volumes.
- The T-VOL capacity exceeds the S-VOL capacity in the relationship being reversed.
- The original relationship was
re-established using the Fast Reverse Restore function.
For information about the Fast Reverse Restore function, see Fast Reverse Restore.
To determine whether the Reverse Restore function can be used, examine the results of the FLASHCOPY QUERY RELATIONS command of ICKDSF. For more information, see Displaying information about Compatible FlashCopy® V2 relationships: FLASHCPY QUERY RELATIONS.
You can use the Reverse Restore function regardless of the incremental type (Type1 or Type2). However, you cannot change the incremental type of existing relationships using the function. When using the function, if you specify the parameter to change the incremental type of the existing relationship, it is ignored, and the function is performed with the original incremental type.
When you perform the Reverse Restore function, only updated data is copied from the new source volume (former target volume) to the new target volume. This is just the reverse of what happens when a standard Incremental FlashCopy® is established.
The Incremental FlashCopy® workflow of Reverse Restore is shown in the following figure.