Each client system has a copy of the default /etc/auto_master map. The +auto_master entry provides a link to the NIS or NIS+ auto_master map. This entry is the first entry in the file in order to ensure that the NIS or NIS+ auto_master map overrides information that is specified locally. The /xfn entry provides a way for the federated name service to map composite names to a reference. For more information on xfn, refer to the xfn(3N) manual page.
NOTE: NIS+ provides backward compatibility with SunOS 4.x auto.master and other auto. files. If the automounter does not find any maps with an auto_ prefix, it searches for maps with the auto. prefix.
The default auto_master map contains a /net mount point as part of an entry that automatically includes all of the systems under the special map -hosts. This built-in map uses the NIS+ hosts.org_dir map to locate exported file systems on a remote host system when the user specifies a system by name. What this means to users is that they can gain access to any files on systems that are listed in the NIS+ Hosts database by using the usual SunOS commands. For example, suppose that Fred sends an email telling you that a document is available on his system for review. Fred includes the system name—oak—and the path to the document—/export/home/fred/Newprojects/review.doc—in the email message. He may show the path as /net/oak/export/home/fred/Newprojects/review.doc. To print the file without copying it to your local system, you would type the following:
castle% lp /net/oak/export/home/fred/Newprojects/review.doc
castle%
To copy the file to your current working directory on your local system, you would type the following:
castle% cp /net/oak/export/home/fred/Newprojects/review.doc.
castle%
If you know that the file is somewhere on the system named oak, but you are not sure of the complete pathname, you can work your way down through the file system, as shown in this example:
castle% cd /net/oak
castle% ls
export
castle% cd export;ls
home
castle% cd home;ls
fred ignatz newton magic
castle% cd fred;ls
Newprojects Status Oldprojects
castle% cd Newprojects;ls
review.doc
castle% pwd
/tmp_mnt/net/oak/export/home/fred/Newprojects
castle%
If NIS+ is not running, the -hosts map consults the /etc/hosts file. For example, if a user types cd /net/castle and the system named castle is in the Hosts database, castle is mounted on /net as /tmp_mnt/net/castle. The -nosuid option prevents users from running setuid programs that are a security threat on the /net mount point.
The default auto_master map also contains a /home mount point and the auto_home map name so that you do not need to make a special entry in the auto_master map for auto_home. SunSoft recommends that you use /home/user-name as your naming convention instead of the SunOS 4.x naming convention of /home/system-name/user-name.
The auto_master map is parsed from top to bottom. The top entry takes precedence. Consequently, when you use NIS+ maps to set up a global namespace, the local /etc/auto_master maps should always have the +auto_master entry at the top of the file.
You can add new entries to the NIS+ auto_master map and take them away, although you should be careful when you delete entries from the NIS+ auto_master map. If you want to change the default mount point, change the /net -hosts entry to /net -null and define your new mount point. For example, to change the mount point to /foo, you would add the entry:
/foo -hosts -setuid
NOTE: Although you can change the default /net mount point, SunSoft recommends that you use the /net mount point to make the automounter easier to administer, to provide a consistent namespace for your users, and to ensure compatibility with future automounter releases. If you have a different default mount point, consider gradually making the transition toward the recommended default.
When you create new indirect or direct maps, you must add the mount points and map names to the NIS+ auto_master table so that the automounter knows to look for them. If you create a direct map, use /- as the mount point. The automounter recognizes this mount point as an instruction to not associate the entries in the auto_direct map with any directory. See Chapter 8 for step-by-step instructions for creating indirect and direct maps and updating the auto_master map.
The Home Directory Map
The home directory map, located in the /etc directory, is named auto_home. The default map contains a +auto_home link to the NIS+ auto_home database.
The syntax of entries in the auto_home map is:
user-name [mount-options] server:pathname
The user’s login name is user-name, which is used as the mount point for the home directory. An optional, comma-separated list of options, [mount-options], controls the mounting of the user’s home directory. If no options are specified, the home directory is mounted read-write. The server:pathname variable specifies the name of the server and the path to the user’s home directory.
This is the default auto_home map:
# Home directory map for automounter
#
+auto_home
Each system has a copy of the default /etc/auto_home map. The +auto_home entry tells the client to use the NIS or NIS+ Auto_home database. SunSoft recommends that you use the Solstice AdminSuite’s Database Manager to administer the NIS+ Auto_home database.
With Solaris 2.3 system software and later, the /tmp_mnt mount point is not displayed as part of the pathname, and the local path is displayed as /home/username.