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 specifying the Secondary Volume Write option in HDvM - SN, or 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.