Pair status
The pair status of a volume indicates the synchronization status of the pair to which it belongs. When a pair operation is performed, the pair status of the volumes changes. The pair status of a volume determines the operations that can be performed on the pair. For example, you can only split a pair when the pair status of the volumes is COPY or PAIR.
During normal operations you need to monitor the pair status to ensure that you can perform the desired operations and to verify that operations completed successfully.