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(8) 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.
OPTIONS
-h, --help
Print brief help on program usage.
-p, --pid-file
Write the pid of the daemon to the specified file.
-t, --timeout
Set the global minimum timeout, in seconds, until directories
are unmounted. The default is 10 minutes. Setting the timeout to
zero disables umounts completely.
-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, --debug
Enables logging of general status and progress messages as well
as debuging messages for all autofs managed mounts.
-Dvariable=value
Define a global macro substitution variable. Global definitions
are over-ridden macro definitions of the same name specified in
mount entries.
-f, --foreground
Run the daemon in the forground and log to stderr instead of
syslog."
-r, --random-multimount-selection
Enables the use of ramdom selection when choosing a host from a
list of replicated servers.
-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.
-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 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.
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 autofs managed
mount points during 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 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.
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 recoverd 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 already
running is used be aware that autofs currently may not function
correctly for certain types of automount maps. The mounts of the
seperate 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 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.
SEE ALSO
autofs(5), autofs(8), 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@linux.kernel.org>. For instructions on how to join the list and
for archives visit http://linux.kernel.org/mailman/listinfo/autofs
AUTHOR
H. Peter Anvin <hpa@transmeta.com> and Ian Kent <raven@themaw.net>.
12 Apr 2006