Default Autofs Behavior With Name Services

Booting invokes autofs using the /etc/init.d/autofs script and checks for the master auto_master map (subject to the rules discussed subsequently).

Autofs uses the name service specified in the automount entry of the /etc/nsswitch.conf file. If NIS+ is specified, as opposed to local files or NIS, all map names are used as is. If NIS is selected and autofs cannot find a map that it needs, but finds a map name that contains one or more underscores, the underscores are changed to dots, which allows the old NIS file names to work. Then autofs checks the map again, as shown in Figure 31-4.

Figure 31-4 How Autofs Uses the Name Service

The screen activity for this session would look like the following example.

$ grep /home /etc/auto_master
/home           auto_home

$ ypmatch brent auto_home
Can't match key brent in map auto_home.  Reason: no such map in
server's domain.

$ ypmatch brent auto.home
diskus:/export/home/diskus1/&

If "files" is selected as the name service, all maps are assumed to be local files in the /etc directory. Autofs interprets a map name that begins with a slash (/) as local regardless of which name service it uses.