Consoles and Migration ID Exits › Extended MCS Consoles › Migration IDs

Migration IDs

It is possible to assign a unique migration ID to an extended MCS console. The ID is required to issue commands to those applications that do not support named consoles. Across a sysplex, there is a limit of 150 migration IDs.

When a region issues commands internally by using an extended MCS console, it decides whether a migration ID is required through its migration ID determination exit. The exit requests an ID for all MODIFY and STOP system commands, and for any unrecognized commands.

When users issue commands in the region by using the SYSCMD command, they can choose whether a migration ID is required by using the MIGID operand of the SYSCMD command. If the MIGID operand is not specified, the setting specified in the CONSOLES parameter group is used. The default setting is YES, specifying that IDs be used.

The limit of 150 migration IDs may be a problem in a large sysplex where many applications are using extended MCS consoles. If a region cannot acquire a console when requested, the requesting SYSCMD command fails. Use the following suggestions to help you correct the problem:

• In the CONSOLES parameter group, change the value in the Acquire with Migration ID (default) field to NO.
• Consider writing your own migration ID determination exit to further restrict the use of IDs by internally issued commands. A sample exit, NMMIGIDX, is supplied with the product.