automount - configure mount points for autofs

automount [options] mount-point map-type[,format] map [map-options]

The automount program is used to configure a mount point for autofs, the inlined Linux automounter. automount works by taking a base mount-point and map file, and using these (combined with other options) to automatically mount filesystems within the base mount-point when they are accessed in any way. The filesystems are then autounmounted after a period of inactivity.

-p, --pid-file

Write the pid of the daemon to the specified file.

-t, --timeout

Set the minimum timeout, in seconds, until directories are unmounted. The default is 5 minutes. Setting the timeout to zero disables unmounts completely.

-v, --verbose

Enables printing of general status and progress messages.

-d, --debug

Enables printing of general status and progress messages as well as debuging messages.

-g, --ghost

Request that directories in the automount be shown but not mounted until accesssed. The wildcard map is not ghosted.

-V, --version

Display the version number, then exit.

automount takes at least three arguments. Mandatory arguments include mount-point, map-type, and map. Both mandatory and optional arguments are described below.

mount-point

Base location for autofs-mounted filesystems to be attached. This is a directory name that will be created (as with mkdir -p) and later when automount terminates will be removed (as with rmdir -p).

map-type

Type of map used for this invocation of automount. The following are valid map types:

file

The map is a regular text file.

program

The map is an executable program, which is passed a key on the command line and returns an entry on stdout if successful.

yp

The map is a NIS (YP) database.

nisplus

The map is a NIS+ database.

hesiod

The map is a hesiod database whose filsys entries are used for maps.

ldap

map names are of the form [//servername/]basedn, where the optional servername is the name of the LDAP server to query, and basedn is the DN to do a subtree search under. Two LDAP schema are supported. The automountMap and the nisMap (RFC 2307) object classes.

Entries in the automountMap schema are automount objects in the specified subtree, where the cn attribute is the key (the wildcard key is "/"), and the automountInformation attribute contains the information used by the automounter. Documentation on the schema used by this module is available online at http://docs.sun.com/source/806-4251-10/mapping.htm.

RFC 2307 schema entries are nisObject objects and use the cn attribute as the key and the nisMapEntry contains information used by the automounter.

format

Format of the map data; currently the only formats recognized are sun, which is a subset of the Sun automounter map format, and hesiod, for hesiod filesys entries. If the format is left unspecified, it defaults to sun for all map types except hesiod.

map

Location of mapfile to use. This is an absolute UNIX pathname in the case for maps of types file or program, and the name of a database in the case for maps of type yp, nisplus, or hesiod.

options

Any remaining command line arguments without leading dashes (-) are taken as options (-o) to mount. Arguments with leading dashes are considered options for the maps. The sun format supports the following options:

-Dvariable=value

Replace variable with value in map substitutions.

-strict

Treat errors when mounting file systems as fatal. This is important when multiple file systems should be mounted (`multimounts'). If this option is given, no file system is mounted at all if at least one file system can't be mounted.

If the automount daemon catches signal USR1, it will unmount all currently unused autofs-mounted filesystems and continue running (forced expire). If it catches signals TERM or USR2 it will unmount all unused autofs-mounted filesystems and exit if all filesystems were unmounted. Busy filesystems will not be unmounted. The daemon also responds to a HUP signal which triggers an update of maps for which ghosting is implemented (currently FILE and NIS maps).

If the autofs directory itself is busy when the daemon is signalled with an exit signal then the daemon will exit without unmounting the autofs filesystem. The filesystem is left in a catatonic (non-functional) state, and can be unmounted when it becomes unused.

autofs(5), mount(8).

A whole slew of missing desirable features (see TODO file).

The documentation leaves a lot to be desired.

Please report other bugs along with a detailed description to <autofs@linux.kernel.org>. For instructions on how to join the list and for archives visit http://linux.kernel.org/mailman/listinfo/autofs

H. Peter Anvin <hpa@transmeta.com>