When a volume is added to a session by the XADDPAIR command, the system data mover uses the volume serial number to determine which storage control the volume belongs to and which channel connection address to use to address the volume. If the channel connection address for an XRC volume pair is changed while the pair is still in an active XRC session, the SDM is unable to perform the copy operation. The following scenario describes how to register a changed channel connection address with the SDM.