Advanced Topics › Control and Checkpoint File Considerations › How You Migrate to a New Control File

How You Migrate to a New Control File

Control file migration is the process by which CA MIM leaves its current control file and begins using another control file to communicate globally.

When control file migration begins on a system, that system changes the control file status for all other systems. This lets other systems to see that migration has begun, and causes them to join the migration process automatically the next time they access the control file. You do not need to initiate migration on other systems unless a system does not join the migration process.

CA MIM may automatically migrate to a new control file as part of error recovery in the following cases:

• If the current control file becomes unusable.
• When migrating from one virtual control file to another in a CTCDASD environment, CA MIM migrates to the DASD control file or coupling facility structure control file for a few seconds while re-synchronization takes place. After synchronization, the virtual control file automatically migrates to the new virtual control file.

Note: You can use the MIGRATE command to switch control files for performance reasons, to replace a control file that has become unusable, or to activate or deactivate a virtual control file while running under the CTCDASD communication method.