automount(8) — Linux manual page
AUTOMOUNT(8) System Manager's Manual AUTOMOUNT(8)
NAME
automount - manage autofs mount points
SYNOPSIS
automount [options] [master_map]
DESCRIPTION
The automount program is used to manage mount points for autofs,
the inlined Linux automounter. automount works by reading the
auto.master(5) map and sets up mount points for each entry in the
master map allowing them to be automatically mounted when ac‐
cessed. The file systems are then automatically umounted after a
period of inactivity.
OPTIONS
-h, --help
Print brief help on program usage.
-p, --pid-file
Write the pid of the daemon to the specified file.
-t <seconds>, --timeout <seconds>
Set the global minimum timeout, in seconds, until directo‐
ries are unmounted. The default is 10 minutes. Setting the
timeout to zero disables umounts completely. The internal
program default is 10 minutes, but the default installed
configuration overrides this and sets the timeout to 5
minutes to be consistent with earlier autofs releases.
-M <seconds>, --master-wait <seconds>
Set the maximum time to wait for the master map to become
available if it cannot be read at program start.
-n <seconds>, --negative-timeout <seconds>
Set the default timeout for caching failed key lookups.
The default is 60 seconds.
-v, --verbose
Enables logging of general status and progress messages
for all autofs managed mounts.
-d[LEVEL], --debug[=LEVEL]
Enables logging of general status and progress messages as
well as debugging messages for all autofs managed mounts.
The default LEVEL is 0. automounter must perform OpenLDAP
authenticated binds for optional argument LEVEL to have
any effect. OpenLDAP uses a bitmap to enable debugging for
specific components. Debug LEVEL=0 disables libldap deug‐
ging. For further details see slapd(8).
-Dvariable=value, --define variable=value
Define a global macro substitution variable. Global defin‐
itions are over-ridden macro definitions of the same name
specified in mount entries.
-S, --systemd-service
Used when running the automounter as a systemd service to
ensure log entry format is consistent with the log entry
format when running as a daemon.
-f, --foreground
Run the daemon in the foreground and log to stderr instead
of syslog."
-r, --random-multimount-selection
Enables the use of random selection when choosing a host
from a list of replicated servers.
-m, --dumpmaps [<map type> <map name>]
With no parameters, list information about the configured
automounter maps, then exit.
If the dumpmaps option is given and is followed by two pa‐
rameters, "<map type> <map name>" then simple "<key, val‐
ue>" pairs that would be read in by a map read are printed
to stdout if the given map type and map name are found in
the map configuration.
If the map is an LDAP map and there is more than one map
of same name in different base dns only the first map en‐
countered by autofs will be listed. Similarly, if the map
is a file map and there is more than one map of the same
name in different directories, only the first map encoun‐
tered will be listed.
If the map type is an old style multi-map and any one of
the map names in the multi-map entry matches the given map
name the entries that would be used by autofs for the
whole multi-map will be listed.
-O, --global-options
Allows the specification of global mount options used for
all master map entries. These options will either replace
or be appended to options given in a master map entry de‐
pending on the APPEND_OPTIONS configuration setting.
-V, --version
Display the version number, then exit.
-l, --set-log-priority priority path [path,...]
Set the daemon log priority to the specified value. Valid
values include the numbers 0-7, or the strings emerg,
alert, crit, err, warning, notice, info, or debug. Log
level debug will log everything, log levels info, warn (or
warning), or notice with enable the daemon verbose log‐
ging. Any other level will set basic logging. Note that
enabling debug or verbose logging in the autofs global
configuration will override dynamic log level changes. For
example, if verbose logging is set in the configuration
then attempting to set logging to basic logging, by using
alert, crit, err or emerg won't stop the verbose logging.
However, setting logging to debug will lead to everything
(debug logging) being logged witch can then also be dis‐
abled, returning the daemon to verbose logging. This op‐
tion can be specified to change the logging priority of an
already running automount process.
The path argument corresponds to the automounted path name
as specified in the master map.
-C, --dont-check-daemon
Don't check if the daemon is currently running (see
NOTES).
-F, --force
Force an unlink umount of existing mounts under configured
autofs managed mount points during startup. This can cause
problems for processes with working directories within
these mounts (see NOTES).
-U, --force-exit
Force an unlink umount of existing mounts under configured
autofs managed mount points and exit rather than continu‐
ing the startup. This can cause problems for processes
with working directories within these mounts (see NOTES).
ARGUMENTS
automount takes one optional argument, the name of the master map
to use.
master_map
Location for autofs master map that defines autofs managed
mount points and the mount maps they will use. The default
is auto.master.
NOTES
If the automount daemon catches a USR1 signal, it will umount all
currently unused autofs managed mounted file systems and continue
running (forced expire). If it catches the TERM signal it will
umount all unused autofs managed mounted file systems and exit if
there are no remaining busy file systems. If autofs has been com‐
piled with the option to ignore busy mounts on exit it will exit
leaving any busy mounts in place otherwise busy file systems will
not be umounted and autofs will not exit. Alternatively, if aut‐
ofs has been compiled with the option to enable forced shutdown
then a USR2 signal to the daemon will cause all mounts to be
umounted and any busy mounts to be forcibly umounted, including
autofs mount point directories (summary execution). Note that the
forced umount is an unlink operation and the actual umount will
not happen in the kernel until active file handles are released.
The daemon also responds to a HUP signal which triggers an update
of the maps for each mount point.
If any autofs mount point directories are busy when the daemon is
sent an exit signal the daemon will not exit. The exception to
this is if autofs has been built with configure options to either
ignore busy mounts at exit or force umount at exit. If the ignore
busy mounts at exit option is used the filesystems will be left
in a catatonic (non-functional) state and can be manually umount‐
ed when they become unused. If the force umount at exit option is
used the filesystems will be umounted but the mount will not be
released by the kernel until they are no longer in use by the
processes that held them busy. If automount managed filesystems
are found mounted when autofs is started they will be recovered
unless they are no longer present in the map in which case they
need to umounted manually.
If the option to disable the check to see if the daemon is al‐
ready running is used be aware that autofs currently may not
function correctly for certain types of automount maps. The
mounts of the separate daemons might interfere with one another.
The implications of running multiple daemon instances needs to be
checked and tested before we can say this is supported.
If the option to force an unlink of mounts at startup is used
then processes whose working directory is within unlinked auto‐
mounted directories will not get the correct pwd from the system.
This is because, after the mount is unlinked from the mount tree,
anything that needs to walk back up the mount tree to construct a
path, such as getcwd(2) and the proc filesystem /proc/<pid>/cwd,
cannot work because the point from which the path is constructed
has been detached from the mount tree.
SEE ALSO
autofs(5), autofs(8), autofs.conf(5), auto.master(5), mount(8),
autofs_ldap_auth.conf(5).
BUGS
Don't know, I've fixed everything I know about.
The documentation could be better.
Please report other bugs along with a detailed description to
<autofs@vger.kernel.org>. Visit
http://vger.kernel.org/vger-lists.html#autofs for information
about the list.
AUTHOR
H. Peter Anvin <hpa@transmeta.com> and Ian Kent <raven@the‐
maw.net>.
COLOPHON
This page is part of the autofs (automount) project. Information
about the project can be found at ⟨http://www.autofs.org/⟩. If
you have a bug report for this manual page, send it to
autofs@vger.kernel.org. This page was obtained from the
project's upstream Git repository
⟨git://git.kernel.org/pub/scm/linux/storage/autofs/autofs.git⟩ on
2024-06-14. (At that time, the date of the most recent commit
that was found in the repository was 2024-05-23.) If you
discover any rendering problems in this HTML version of the page,
or you believe there is a better or more up-to-date source for
the page, or you have corrections or improvements to the
information in this COLOPHON (which is not part of the original
manual page), send a mail to man-pages@man7.org
12 Apr 2006 AUTOMOUNT(8)
Pages that refer to this page: autofs(5), autofs.conf(5), auto.master(5), nfs(5), systemd.automount(5), autofs(8)