man/automount.8

.\" Linux man page by B. James Phillippe, 1997 <bryan@Terran.ORG>
.\"
.\" This page was written to contribute to the Linux kernel autofs
.\" implementation by H. Peter Anvin (1997).  It is loosly based on
.\" the documentation for mount(8) and amd(8) Linux manpages.
.\"
.\" This is free documentation.
.\"
.TH AUTOMOUNT 8 "12 Apr 2006"
.SH NAME
automount \- manage autofs mount points
.SH SYNOPSIS
\fBautomount\fP [\fIoptions\fP] [\fImaster_map\fP]
.SH DESCRIPTION
The \fBautomount\fP program is used to manage mount points for
autofs, the inlined Linux automounter.  \fBautomount\fP works by
reading the
.nh
.BR auto.master (5)
.hy
map and sets up mount points for each entry in the master map allowing
them to be automatically mounted when accessed. The file systems are
then automatically umounted after a period of inactivity.
.SH OPTIONS
.TP
.I "\-h, \-\-help"
Print brief help on program usage.
.TP
.I "\-p, \-\-pid-file"
Write the pid of the daemon to the specified file.
.TP
.I "\-t <seconds>, \-\-timeout <seconds>"
Set the global minimum timeout, in seconds, until directories
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.
.TP
.I "\-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.
.TP
.I "\-n <seconds>, \-\-negative\-timeout <seconds>"
Set the default timeout for caching failed key lookups. The default is 60 seconds.
.TP
.I "\-v, \-\-verbose"
Enables logging of general status and progress messages for all
autofs managed mounts.
.TP
.I "\-d, \-\-debug"
Enables logging of general status and progress messages as well as
debugging messages for all autofs managed mounts.
.TP
.I "\-Dvariable=value, --define variable=value"
Define a global macro substitution variable. Global definitions
are over-ridden macro definitions of the same name specified in
mount entries.
.TP
.I "\-f, \-\-foreground"
Run the daemon in the foreground and log to stderr instead of syslog."
.TP
.I "\-r, \-\-random-multimount-selection"
Enables the use of random selection when choosing a host from a
list of replicated servers.
.TP
.I "\-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 parameters,
"<map type> <map name>" then simple "<key, value>" 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 encountered 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
encountered 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.
.TP
.I "\-O, \-\-global-options"
Allows the specification of global mount options used for all master
map entries. These options will either replace or be appened to options
given in a master map entry depending on the APPEND_OPTIONS configuration
setting.
.TP
.I "\-V, \-\-version"
Display the version number, then exit.
.TP
.I "\-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 logging. 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 disabled, returning the daemon to verbose logging. This option can be
specified to change the logging priority of an already running automount
process.
.P
The \fIpath\fP argument corresponds to the automounted
path name as specified in the master map.
.TP
.I "\-C, \-\-dont-check-daemon"
Don't check if the daemon is currently running (see NOTES).
.TP
.I "\-F, \-\-force"
Force an unlink umount of existing mounts under autofs managed mount points
during startup. This can cause problems for processes with working directories
within these mounts (see NOTES).
.SH ARGUMENTS
\fBautomount\fP takes one optional argument, the name of the master map to
use.
.TP
\fBmaster_map\fP
Location for autofs master map that defines autofs managed mount points
and the mount maps they will use. The default is
.nh
\fBauto.master\fP.
.hy
.RE
.SH NOTES
If the \fBautomount\fP 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 compiled 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 autofs 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.
.P
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 umounted 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.
.P
If the option to disable the check to see if the daemon is already
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.
.P
If the option to force an unlink of mounts at startup is used then processes
whose working directory is within unlinked automounted 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.
.SH "SEE ALSO"
.BR autofs (5),
.BR autofs (8),
.BR autofs.conf (5),
.BR auto.master (5),
.BR mount (8),
.BR autofs_ldap_auth.conf (5).
.SH 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.
.SH AUTHOR
H. Peter Anvin <hpa@transmeta.com> and Ian Kent <raven@themaw.net>.