The Global Mirror RSESSION START request was rejected by the storage control because the maximum number of active sessions has been reached on the master or for one of the subordinates specified on the request.
The command is rejected.
Verify that the correct Global Mirror session is specified, and that you are not starting more sessions than are supported for the master or subordinates specified. After making any changes or corrections, resubmit the request.
Peer-To-Peer Remote Copy (PPRC).