How to join IMS with the availability manager

The availability manager (AVM) has its own address space. You can start the AVM with the z/OS START command or let z/OS® start it automatically when you issue the IMS /NRESTART or /ERESTART command. To start the availability manager, issue the z/OS START AVM command. When the AVM is initialized, you receive the AVM001I message.

Recommendation: Use the z/OS START AVM,SUB=MSTR command to start the AVM. If you omit the SUB=MSTR keywords, z/OS starts the AVM from the JES address space, and the resulting dependency on JES means you cannot stop JES without also stopping the AVM.

Both the active subsystem and the alternate subsystem notify the z/OS availability manager of their participation in an RSE during initialization. When IMS successfully joins the AVM and RSE, you receive messages DFS3871I and DFS3873I.

If IMS fails to connect to the AVM, you receive message DFS3872I. If the connection fails, the operator must initiate I/O prevention during XRF takeover.

You must have a procedure established in case the connection fails during initialization of either the active subsystem or the alternate subsystem. You might want to determine the cause of the failure and restart the initialization to ensure that the connection is successful.