By specifying the Read option for the S-VOL, you can read the S-VOL from the host while the pair is split without deleting the pair from the secondary storage system. If you split the pair by using the pairsplit -rw command in CCI, you can write to the S-VOL. In this case, S-VOL and P-VOL track maps keep track of differential data and are used to re-synchronize the pair. Enabling Secondary Volume Write is done during the pairsplit operation.
- You can write to S-VOL when the split operation is performed from the primary system.
- When you resync a pair with the Secondary Volume Write option enabled, the secondary system sends S-VOL differential data to the primary system. This data is merged with P-VOL differential data, and out-of sync tracks are determined and updated on both systems, thus ensuring proper resynchronization.