Understanding User Name Mapping

User Name Mapping acts as a single clearinghouse that provides centralized user mapping services for Interix, Client for NFS, Gateway for NFS, Server for NFS, and Remote Shell service.

User Name Mapping lets you create maps between Windows and UNIX user and group accounts even though the user and group names in both environments may not be identical. Perhaps most important, User Name Mapping lets you maintain a single mapping database for the entire enterprise. This makes it easy to configure authentication for multiple computers running Windows Services for UNIX.

In addition to one-to-one mapping between Windows and UNIX user and group accounts, User Name Mapping permits one-to-many mapping. This lets you associate multiple Windows accounts with a single UNIX account. This can be useful, for example, when you do not need to maintain separate UNIX accounts for individuals and would rather use a few accounts to provide different classes of access permission.

You can use simple maps, which map Windows and UNIX accounts with identical names. You can also create advanced maps to associate Windows and UNIX accounts with different names, which you can use in conjunction with simple maps. For information about simple and advanced maps, see Simple and advanced maps.

User Name Mapping can obtain UNIX user, password, and group information from one or more Network Information Service (NIS) servers or from passwd and group files located on a local hard drive. The passwd and group files can be copied from a UNIX computer running the PCNFS daemon (PCNFSD) or a Windows computer running Server for PCNFS. See To configure User Name Mapping for more information about specifying the source for UNIX user information.

User Name Mapping periodically refreshes its mapping database from the source databases, ensuring that it is always kept up to date as changes occur in the Windows and UNIX name spaces. You can also refresh the database anytime you know the source databases have changed. For information on how to refresh the database automatically and manually, see To set the refresh interval for maps and To refresh data now.

You can back up and restore User Name Mapping data at any time. Because the database is backed up to a file, you can use that file to copy the mapping database to another server. This provides redundancy for the sake of fault tolerance. To learn how to back up and restore the mapping database, see To back up and restore maps.

If you obtain information from multiple NIS domains, it is assumed that each domain have unique users and user identifiers (UIDs). User Name Mapping does not perform any checks.