Filesystem Administration  «Prev  Next»

Lesson 5 Setting up the automounter
Objective Set up the automounter.

Setting up Automounter

amd vs. autofs

There are two Linux automounters that can be configured and used on the Linux system: amd and autofs. amd is user-level and requires no kernel support; autofs requires kernel support, but is simpler to administer.
autofs kernel support is built into the stock kernel installed by the Red Hat Linux distribution. However, the autofs RPM must be installed and local configuration may be required.
map file definition: "in automounter parlance, a configuration file that associates a directory key with a device to mount when that directory key is accessed."
autofs has a master configuration file and a second type of configuration file, a map file for each autofs filesystem mount point.

autofs master file

The master configuration file /etc/auto.master contains the overall automount configuration, illustrated in the following MouseOver.
automatster over
  1. This is the mount point, the location where the autofs filesystem associated with map will be mounted on the local filesystem, in this case ./misc
  2. This is the map file associated with the autofs filesystem. The map file contains entries for the devices to be mounted on the mount point
  3. These are options associated with all the devices listed in the map file. In this case, all devices listed in /etc/auto.misc automatically will be unmounted after 60 seconds of disuse

autofs Filesystem Location

autofs map file

The map file /etc/auto.misc has entries such as the following:
1) cd, 2) floppy, 3) -fstype=iso9660,ro, 4) -fstype=auto, 5) :/dev/cdrom. 6) :/dev/fd0
1) cd, 2) floppy, 3) -fstype=iso9660,ro, 4) -fstype=auto, 5) :/dev/cdrom. 6) :/dev/fd0

Mount Point Access

Other options

/etc/rc.d/init.d/autofs status will report the status and location of all automounter active mount points. Other options that can be used with autofs include start, stop, and reload, which perform the obvious actions. For example, /etc/rc.d/init.d/autofs stop will stop the automounter and deactivate any currently active automatic mount points.
If you make changes to the automounter, you should reboot to verify that it comes up. If it fails, you should make autofs automatically run with the command chkconfig, add autofs.
The following simulation walks you through the process of setting up the automounter.
Perform Redhat Automounter Steps
T he next lesson describes network file synchronization.

SettingUp Automounter

Before moving on to the next lesson, click the link below to check your understanding of how to set up the automounter.
Setting Up Automounter