FDBR recovery process

If the tracked IMS subsystem fails, the FDBR region automatically begins recovery. During automatic recovery, the FDBR region uses the MVS Availability Manager to determine when I/O is complete for the databases and areas it will recover.

During recovery, the FDBR region does the following for all tracked databases and areas:

• Allocates and opens database data sets
• Backs out updates for full-function databases
• Performs REDO processing for DEDB areas

After recovery is complete, the FDBR region tells IRLM to release retained locks for the recovered databases and areas. The FDBR region then issues a message that recovery is complete.

If the tracked IMS subsystem's z/OS® cross-system coupling facility (XCF) fails, the FDBR region stops tracking and issues a message. If the FDBR region's XCF fails, the region abnormally terminates.

To begin recovery manually, issue the z/OS MODIFYfdbrproc, RECOVER command. For manual recovery, the FDBR does not wait for I/O to complete because it assumes the I/O is already complete.