You can use Incremental FlashCopy® to create an initial point-in-time copy of a source volume and refresh the target volume by copying only the changed data. Incremental FlashCopy operates at the full volume level.

After the initial full volume copy of the source volume to the target volume, the FlashCopy relationship remains (persists) between the source and target volume pair and the changes on the source and target volumes since the last point-in-time copy are tracked. When you refresh the target volume at a new point-in-time, only the changed tracks are copied. Incremental FlashCopy helps reduce the physical background copy time when only a subset of the data on the source or target has changed.

The direction of the refresh can be reversed when you indicate the original target now becomes the source and the original source becomes the target. Only the changed data since the last point-in-time copy is copied. If no updates were made to the target since the last incremental copy, the reverse of FlashCopy direction can be used to restore the original source back to the previous point-in-time state.