Windows access to a file created by a UNIX user (or vice-versa) is permitted when the UNIX name and Windows name are recognized as being the same user. However, NFS clients present an NFS operation to an NFS server with numerical UNIX User ID (UID) and UNIX Group ID (GID) as credentials. The server must map the UID and GID to a UNIX user or group name prior to verifying the UNIX to Windows name mapping.
The server uses the following methods to map from a numerical UNIX UID
or GID to a UNIX user name or group name:
- If the server is configured to use the Network Information Service (NIS) no special configuration steps are needed; the server automatically retrieves the user (group) names and IDs from the NIS server.
- NFS user and group names can be added manually.
- NFS user and group names can be added by importing files. For example, the UNIX /etc/passwd file can be imported, providing the server with a mapping of user name to UID. The /etc/groups file should also be imported to provide the server with a mapping of Group name to GID.
- You can import the numerical
ID to Name mappings directly from a NIS server or an LDAP server if one has
been configured. Every time a UID is presented to the server, it will issue an
NIS request to an NIS server to verify the mapping. This mapping can remain
cached in the server for a configurable time. A cached ID to name binding for a
User or Group will appear as Transient in the NFS Users or Groups list.
Note: When a Windows user creates a file and the UNIX user or group mapping fails, the server sets the UID or the GID to 0 (root). In previous releases, the server sets the UID or GID to 0 (root) or to 65534 (nobody).