Dell PowerVault 775N (Rackmount NAS Appliance) - Manual (Page 67)

Mapping from the MMC Console or by using the NAS Manager to configure properties for the NFS Sharing Protocol. With User
Name Mapping, you can create simple maps between Windows Powered user accounts and corresponding UNIX accounts. You
can also use the Advanced Map feature to map accounts with dissimilar names. Because UNIX user names are case-sensitive,
and Windows Powered operating system names are not, the use of User Name Mapping can greatly simplify maintaining and
managing accounts in the two environments. User Name Mapping uses Network Information Service (NIS) or local Personal
Computer Network File System (PCNFS) user and group files to authenticate users. Also, User Name Mapping supports
bidirectional one-to-many mapping, allowing you to map a single UNIX or Windows Powered operating system account to
multiple accounts in the other environment. For example, you can map more than one administrative account in a Windows
Powered operating system to the UNIX root account.
Special Mappings
By default, the root user for the UNIX client is mapped to an unmapped user. This setting is commonly known as "root
squashing." When an NFS authentication request is made for a user name mapped to an unmapped user, the result is an
anonymous UID and GID (typically -2 and -1, respectively). Any files created by such a user will show file ownership as an
anonymous Windows user.
NOTE: To prevent root squashing for specific NFS shares, the UNIX root user and group must be mapped to the Windows
administrator user and group. The "access type" for the NFS share's permissions must also be set to root for each
applicable client or client group.
To create user and group name maps, perform the following steps:
1. Log in to the NAS Manager.
2. From the NAS Manager, click Shares.
3. Click Sharing Protocols.
4. Click NFS Protocol, and then click Properties.
5. Click User and Group Mappings.
6. Use the User and Group Mappings window to define your user and group maps.
To configure the type of server to be used to access UNIX user and group names, perform the following steps:
1. On the User and Group Mappings window, click General.
2. Click Use NIS server, or click Use password and group files to select the server type.
3. Depending on whether you use an NIS server or password and group files, perform one of the following steps:
For password and group files, specify the location and filename of the UNIX password file and UNIX group file.
NOTE: The UNIX password file and group file formats must conform to the UNIX standard for these files.
For NIS server, type the NIS domain and, optionally, the name of the NIS server.
4. Click OK to apply the configuration.
To define simple maps, perform the following steps:
1. In the User and Group Mappings window menu, click Simple Mapping.
2. Click Enable Simple Mapping.
3. Specify the Windows Domain.
4. Click OK to create the maps.