A coupling facility becomes volatile

If a coupling facility changes to the volatile state, the system logger on each system using the coupling facility structure is notified. A dynamic rebuild of the structure is initiated so that the log data can be moved to a non-volatile coupling facility. During rebuild processing, system logger rejects any logger service requests.

If there is not a structure available in a non-volatile coupling facility, system logger will still rebuild the data on a new volatile coupling facility. System logger may then change the way it duplexes coupling facility data since the volatile coupling facility constitutes a single point of failure: