An indirect map uses a substitution value of a key to establish the association between a mount point on the client and a directory on the server. Indirect maps are useful for accessing specific file systems, such as home directories. The auto_home map is an example of an indirect map.
key [ mount-options ] location
key is a simple name without slashes in an indirect map.
mount-options is the options that you want to apply to this particular mount. These options are required only if the options differ from the map default. Options for each specific type of file system are listed in the mount man page for that file system. For example, see the mount_nfs(1M) man page for NFS-specific mount options.
location is the location of the file system. One or more file systems are specified as server:pathname.
The pathname should not include an automounted mount point. The pathname should be the actual absolute path to the file system. For instance, the location of a directory should be listed as server:/usr/local, not as server:/net/server/usr/local.
As in the master map, a line that begins with # is a comment. All the text that follows until the end of the line is ignored. Put a backslash (\) at the end of the line to split long lines into shorter ones. Example 6–3 shows an auto_master map that contains the following entry:
/home auto_home -nobrowse
david willow:/export/home/david rob cypress:/export/home/rob gordon poplar:/export/home/gordon rajan pine:/export/home/rajan tammy apple:/export/home/tammy jim ivy:/export/home/jim linda -rw,nosuid peach:/export/home/linda
As an example, assume that the previous map is on host oak. Suppose that the user linda has an entry in the password database that specifies her home directory as /home/linda. Whenever linda logs in to computer oak, autofs mounts the directory /export/home/linda that resides on the computer peach. Her home directory is mounted read-write, nosuid.
Assume the following conditions occur: User linda's home directory is listed in the password database as /home/linda. Anybody, including Linda, has access to this path from any computer that is set up with the master map referring to the map in the previous example.
Under these conditions, user linda can run login or rlogin on any of these computers and have her home directory mounted in place for her.
Furthermore, now Linda can also type the following command:
% cd ~david
autofs mounts David's home directory for her (if all permissions allow).
No concatenation of options occurs between the automounter maps. Any options that are added to an automounter map override all options that are listed in maps that are searched earlier. For instance, options that are included in the auto_master map are overridden by corresponding entries in any other map.
On a network without a name service, you have to change all the relevant files (such as /etc/passwd) on all systems on the network to allow Linda access to her files. With NIS, make the changes on the NIS master server and propagate the relevant databases to the slave servers. On a network that is running NIS+, propagating the relevant databases to the slave servers is done automatically after the changes are made.