eXtended Recovery Facility. Feature available with DB2, IMS 1 and CICS, providing vastly increased availability for mission-critical applications. XRF creates a mirror system synchronized with the main system; the mirror image can take over immediately in the event of a failure in the primary system (in many, but not all, cases). Can also be used for planned machine maintenance by purposely switching to a backup system while working on the main system. See also mirroring.