TM resources: user IDs

The user ID identifies a person signed on to a terminal for security authorization by a security product such as RACF®.

The user ID and the user name are usually the same, but see TM resources: user names for an example of when they are not the same.

User ID name uniqueness

You can decide whether to enforce name uniqueness for user IDs. The default is to enforce user ID name uniqueness. If you want one user ID to be able to sign on to multiple terminals at a time (name uniqueness not enforced), use the IMS startup parameter SGN=M.

User ID creation and deletion

When a user signs on to a terminal and single-signon enforcement is requested, IMS defines the user ID to RM. Once a user is signed onto a VTAM® terminal in the IMSplex, any signon attempt by that user is rejected. When a user ID becomes inactive, IMS deletes it from RM. A user ID is deleted in two situations:

During user signoff
During resource cleanup after an IMS failure