The pair status is managed by the primary storage system which manages the P-VOLs.
- The primary storage system is able to change the pair status of the P-VOL and the S-VOL.
- The secondary storage system can change the pair status of the S-VOLs, but cannot change the pair status of the P-VOLs. The primary storage system detects the change of the pair status of S-VOL, and then change the status of P-VOL.
- The pair status changes as follows:
- If the volume is not assigned to a TrueCopy pair, the volume status is SMPL.
- When the initial copy begins to create a pair, the primary storage system changes the status of both volumes to COPY (volumes to be copying).
- When the initial copy completes, the primary storage system changes the status of both volumes to PAIR (volumes become a pair).
- When user splits the pair from the primary storage system or the secondary storage system, the status of the P-VOL and the S-VOL are changed to PSUS (pair suspended-split: split by a command).
- The primary storage system cannot keep the synchronization of the P-VOL and the S-VOL by some reasons, for example errors, the primary storage system changes the status of the P-VOL and the S-VOL to PSUE (pair suspended-error: split by an error).
- When the user removes the pair from the primary storage system, the primary storage system changes the status of the P-VOL and the S-VOL to SMPL.
- When the user removes the pair from the secondary storage system, the secondary storage system changes the status of the S-VOL to SMPL, and then the primary storage system detects the removal of the pair at the secondary system (if the path is normal), the primary storage system changes the status of the P-VOL to PSUS.