Planned takeover

You can apply hardware or software maintenance to either subsystem in an XRF complex as long as you do not change the log record format, make system definition changes (and bring up an alternate subsystem with those changes), or apply maintenance that requires an IMS cold start in a non-XRF environment.

To apply maintenance to the alternate subsystem: terminate it, leaving the active subsystem without an alternate subsystem for the time that you take to apply the maintenance. Then bring that subsystem back up as the alternate subsystem.

To apply maintenance to the active subsystem: initiate a planned takeover to shift its workload to the alternate subsystem. After you apply maintenance, bring up that subsystem as a new alternate subsystem. Initiate another takeover to return the subsystem to its role as the active subsystem.