Migration considerations for the disablement of Extended Recovery Facility (XRF)

As of IMS 15.2, Extended Recovery Facility (XRF) is no longer supported.

If you are migrating an IMS 15.1 or earlier system to 15.2 and the IMS system you are migrating was part of an XRF complex, the XRF capability will be deactivated after the system is migrated to 15.2.

If you are migrating to IMS 15.2 an IMS 15.1 or earlier system that was the active system in an XRF complex, you must cold start the system after migration. If you warm start instead the IMS system that was the active system in the XRF complex, an abend might be issued due to log reading error.

If, however, you are migrating to IMS 15.2 an IMS system that was not previously the active IMS system in an XRF complex, you do not need cold start the system after migration. You can warm start the system instead.

The following XRF-related commands are no longer accepted by IMS 15.2 or later systems:
/ERE BACKUP
To manually restart the IMS alternate system in an XRF complex. If you use the /ERESTART BACKUP command after migration to restart the IMS system that was the alternate system in the XRF complex, message DFS110I COMMAND KEYWORD BACKUP INVALID FOR ACTIVE is issued.
/DISPLAY HSB
To display the system-related information in an Extended Recovery Facility (XRF) environment. If you use the /DISPLAY HSB command after migration, message DFS3813 is issued.
/SWITCH
To switch active data sets or to change between the active and alternate systems. If you use the /SWITCH command after migration, message DFS3813 or DFS110I, or both, are issued.
/START SURV
To start the operation of the IMS surveillance function in an XRF environment. If you use the /START SURV command after migration, message DFS3805 is issued.
/STOP SURV
To stop the operation of the IMS surveillance function in an XRF environment. If you use the /STOP SURV command after migration, message DFS3805 is issued.

In an XRF complex, logs and data for access to application databases are stored in a DASD that is shared between the active and the alternate IMS systems. After an IMS 15.1 or earlier system is migrated to IMS 15.2, each IMS system must have its own log data sets, such as OLDS, WADS, RDS, and so on, for each system to restart. If each IMS system does not have its own log data sets, you can start only one of the IMS systems after migration.