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 for Mainframe pair, the volume status is Simplex.
- When the initial copy begins to create a pair, the primary storage system changes the status of both volumes to Pending (volumes to be copying).
- When the initial copy completes, the primary storage system changes the status of both volumes to Duplex (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 Suspend.
- 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 Suspend.
- 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 Simplex.
- When the user removes the pair from the secondary storage system, the secondary storage system changes the status of the S-VOL to Simplex, 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 Suspend.