The Process User ID is the UNIX user ID under which all Enterprise Servers started from Enterprise Server Administration run. You need to supply a Process User ID because the Directory Server itself has to run as root, and without specifying a different user ID the enterprise servers started from the Directory Server would also run as root. The Process User ID is normally supplied at installation time by the installer. If it was not supplied at installation time, you have to supply it before you can use Enterprise Server. You should choose a user ID that has permission to do everything that the applications you plan to run in Enterprise Server need to do, for example, access data files. This user ID should already exist on the system. To provide a Process User ID, you must run the command casperm. This command also gives you the opportunity to configure some other aspects of Enterprise Server.
Once you have configured Enterprise Server and the Directory Server, you can change the Process User ID on the Configuration Options page. If you change it you must supply a user ID already known to the UNIX system.