7.8. User ID problems

Within an HACMP cluster, you always have more than one node potentially offering the same service to a specific user or a specific user ID.

As the node providing the service can change, the system administrator has to ensure that the same user and group is known to all nodes potentially running an application. So, in case one node is failing, and the application is taken over by the standby node, a user can go on working, because the takeover node knows that user under exactly the same user and group ID. Since user access within an NFS mounted file system is granted based on user IDs, the same situation applies to NFS mounted file systems.