automount Daemon

Purpose

Mounts automatic mount points.

Syntax

/usr/sbin/automount [ -m ] [ -n ] [ -v ] [ -t duration ] [ -i interval ] [ -f file ] [ -s timeout ] [ -D value ] [ -d value ]

Description

The automount command is used as an administration tool for AutoFS. It installs AutoFS mount points and associates an automount map with each mount point. The AutoFS file system monitors attempts to access directories within it and notifies the automountd daemon. The daemon uses the map to locate a file system, which it then mounts at the point of reference within the AutoFS file system.

The previous automount behavior can be specified if the COMPAT_AUTOMOUNT environment variable is set to any value before running the automount command. The current behavior became the default behavior in AIX® 5.0.

If the file system is not accessed within an appropriate interval (ten minutes by default), the automountd daemon unmounts the file system.

If the automountd daemon has not been started the automount command attempts to start it using SRC.

Maps

Automount maps specify the mount points to be automatically mounted when accessed, and what should be mounted over those mount points. The /etc/auto_master map file specifies the initial mount points, known as keys, and their corresponding maps that determine which remote filesystem is mounted over it. The format of the /etc/auto_master file is:

/key    map

Note: The /etc/auto_master file is only read when the automount command is initially executed. Changes to it will not take effect until the automount command is run again.

The most common maps are direct maps, indirect maps, and host maps.

Direct maps require a special key (/-) in the /etc/auto_master file, and their map is a file with the following format:

/directkey     [-options]    server:/dir

When a user accesses the /directkey directory, the automountd daemon will mount server:/dir over /directkey.

Indirect maps have the following format:

indirectkey    [-options]    server:/dir

When a user accesses the /key/indirectkey directory, the automountd daemon will mount server:/dir over /key/indirectkey.

Host maps require a special map (-hosts) in the /etc/auto_master file. The automountd daemon will create a subdirectory under the /key directory for every server listed in the /etc/hosts file. When a user accesses the /key/server directory, the automountd daemon will mount the server's exported directories over the /key/server directory.

Alternate Map Locations

Automount maps may also be located on NIS/NIS+ and LDAP servers. The automount command will look for maps as files on the local system by default, unless the automount entry in the /etc/irs.conf file is changed. For example:

automount nis_ldap

It is possible to specify more than one name service, in the order that they will be used, by using a whitespace separated list. For example, to indicate that LDAP maps should be used first, followed by local files, the automount entry would be the following:

automount nis_ldap files

The valid values for the automount entry are files, nis, nisplus, and nis_ldap.

Flags

Item	Description
-d value	Specifies the debug level of the autofs extension and automount daemon.
-D value	Specifies an environment variable and its value.
-f file	Specifies a new master map file to use. The default is /etc/auto_master.
-i Interval	Specifies the amount of time, in seconds, that an inactive autofs mounted directory exists.
-m	Specifies not to search NIS for automount maps.
-n	Specifies the nobrowse option.
-s timeout	Specifies the amount of time, in seconds, before a new process is forked off if a mount takes too long. The minimum value is 30.
-t Duration	Specifies the amount of time, in seconds, that the auto unmount process sleeps before it starts to work again. The minimum value is 21. The default value is 120. The maximum value is 600.
-v	Displays on standard output verbose status and warning messages.

Files

Item	Description
/etc/auto_master	The default map file used to create the initial automount keys.
/etc/hosts	Specifies servers that will be used in automount host maps.
/etc/irs.conf	Specifies the location of the automount maps.