The system-managed processes involve a series of phases, during which the system coordinates all activities required to rebuild or duplex the structure. The system is responsible for managing the structure and its contents. While the system is managing the rebuild or duplexing rebuild process, it will perform actions on behalf of the connector while running in the connector's address space and perform system-based processing from the XCF address space to reconstruct the new structure from the old structure.

The connector is responsible for recognizing three events — Structure Temporarily Unavailable, Structure State Change, and Structure Available — and must respond to the Structure Temporarily Unavailable event before the system assumes responsibility for managing the subsequent rebuild or duplexing rebuild process.

Note that if there are no active connectors to the structure, the Startup, Quiesce, Attach, and Cleanup phases will not be driven.

A system-managed rebuild and duplexing rebuild process transitions through these phases but a response from the connector is only required during the Startup phase for the Structure Temporarily Unavailable event. The other system-managed phases are not externalized to the connector through event exit events, but are handled internally by MVS™. The IXCQUERY macro and DISPLAY XCF messages provide information about the structure during the entire rebuild or duplexing rebuild process.

A brief description of each of the system-managed phases follows.