Internal User Repository
If the Nirvana.directory.provider system property is set to com.pcbsys.foundation.security.auth.fSAGInternalUserRepositoryAdapter, then usernames will be looked up in a standard Software AG store called the 'Internal User Repository', which is a flat file maintained by the SAG command-line utility internaluserrepo.sh (found in INSTALLROOT/common/bin).
This mechanism is the default user repository if the Nirvana.directory.provider property is not set.
The location of the file containing the user repository is given by the system property, Nirvana.auth.sagrepo.path, and would default to ./users.txt (relative to runtime directory of UM server), but the nserver.conf shipped with UM overrides this as ../users.txt, locating it in the same INSTALLROOT/nirvana/server/umserver directory as the licence.xml file. The nserver.conf file may of course be edited as usual to move the users.txt file into a location that is shared by all the realms of an installed UM instance.
For more information, see
Server-side Authentication in the Universal Messaging Developer Guide.