To stop a system-managed duplexing rebuild, use either the SETXCF STOP,REBUILD,DUPLEX command or the IXLREBLD macro. The system might also stop the duplexing rebuild, for example, in response to a failure affecting one of the structure instances, or a change in the CFRM policy DUPLEX specification to DISABLED.

Users can stop the duplexing rebuild process assuming that it has not already been stopped. When a duplexing rebuild process is stopped to fall back to the old (primary) instance, the phases can be Copy Stop, Stop, or Quiesce for Stop. When a duplexing rebuild process is stopped to switch to the new (secondary) instance, the phases are Switch and Cleanup. Stopping a duplexing rebuild to switch to the new structure is only allowed from the Duplex Established phase. The system rejects requests to switch to the new structure during all other phases of the process with appropriate return and reason codes.