Autofs Programs

Two programs support the autofs service. Both are run when a system is booted, but only automountd is persistent.

automount

This command installs autofs mount points and associates the information in the automaster files with each mount point. The syntax of the command is:

automount [ -t duration ] [ -v ]

where -t duration sets the time, in seconds, that a file system is to remain mounted, and -v selects the verbose mode. Running this command in the verbose mode allows for easier troubleshooting.

If not specifically set, the value for duration is set to 5 minutes. In most circumstances this is a good value; however, on systems that have many automounted file systems, you might need to increase the duration value. In particular, if a server has many users active checking the automounted file systems every five minutes can be inefficient. Checking the autofs file systems every 1800 seconds (or 30 minutes) could be more optimal. By not unmounting the file systems every 5 minutes, it is possible that /etc/mnttab, which is checked by df, can get very large. The output from df can be filtered by using the -F option (see the df(1M) man page) or by using egrep to help fix this problem.

Another factor to consider is that changing the duration also changes how quickly changes to the automounter maps will be reflected. Changes will not be seen until the file system is unmounted. Refer to "Modifying the Maps" for instructions on how to modify automounter maps.

automountd

This daemon handles the mount and unmount requests from the autofs service. The syntax of the command is:

automountd [ -Tnv ] [ -D name=value ]

where -T selects to display each RPC call to standard output, -n disables browsing on all autofs nodes, -v selects to log all status messages to the console, and -D name=value substitutes value for the automount map variable indicated by name. The default value for the automount map is /etc/auto_master. Use the -T option for troubleshooting.