Problems that can occur in the delta resync operation
Journal data will not exist, and therefore the delta resync operation will fail, in the following cases:
After creating the UR pair, the primary delta resync P-VOL is updated but not the UR P-VOL.
When the multi-target P-VOL is resynchronized after the TC pair was split.
When the UR S-VOL is resynchronized after it was split.
When the UR pair is resynchronized after being split and then the journal volume at the TC secondary site exceeds 70%.
When the delta resync P-VOL is updated, and then the journal volume at the TC secondary site exceeds 70%.
When the delta resync pair is created and no volumes (including volumes after failover or failback) in the primary site are updated.
When the status of the UR delta resync pair becomes HLDE, the journal data necessary for the delta resync operation might be discarded. In this case, all data in the delta resync P-VOL would be copied to the delta resync S-VOL.
Do not assign the P-VOL of an SI pair that uses a DP-VOL to the S-VOL of the UR delta resync pair.