Your system programmer can convert your RACF® database to stage 3 of application identity mapping using the IRRIRA00 conversion utility. See z/OS Security Server RACF System Programmer's Guide for information about running the IRRIRA00 conversion utility. In stage 3, RACF locates application identities, such as UIDs and GIDs, for users and groups by looking in VLF and then using an alias index that is automatically maintained by RACF. This allows RACF to more efficiently handle authentication and authorization requests from applications such as z/OS UNIX than was possible using other methods, such as the UNIXMAP class. Once your installation reaches stage 3 of application identity mapping, you will no longer have UNIXMAP class profiles on your system, and you can deactivate the UNIXMAP class.