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autofsmount(8)
NAME
autofsmount - Installs and removes AutoFS intercept points
SYNOPSIS
/usr/sbin/autofsmount [-emuUv] [-D name=value] [-h hostname] [-M mapname]
[-t directory] [-f master-file] [directory map [-mount-options]]
OPTIONS
-D name=value
Defines an AutoFS environment variable by assigning value to the
variable.
-e Prefixes all autofsmount command options with those stored in the
user-defined AUTOFSMOUNT_EXPARGS environment variable. See ENVIRONMENT
VARIABLES.
If specified, this option must appear as the first option in the
command string.
-h hostname
Unmounts all file systems in the export list for a given host.
-m Ignores directory-mapname pairs listed in the auto.master NIS database.
-M mapname
Unmounts all file systems associated with a given AutoFS map.
-t directory
Unmounts a directory subtree starting with the given directory.
-u Unmounts all file systems mounted by autofsd and removes all AutoFS
intercept points.
-U Unmounts (forcefully) all file systems mounted by autofsd and removes
all AutoFS intercept points.
-v Enables verbose output.
-f master-file
Uses master-file for a list of initial directory to mapname pairs,
ahead of the auto.master NIS map. If an entry exists in both master-
file and auto.master, the one specified in master-file is used since it
is read first. Similarly, entries on the command line take precedence
over master-file entries. This technique can be used to replace
entries in global maps with your own. A fully-qualified path name
designates a user-supplied file to read as the master file; otherwise,
the name is considered an NIS map name.
directory
Specifies the full pathname of a local directory if the map argument is
the name of an indirect map or the name of a special map. If the map
argument is the name of a direct map, the dummy directory /- is
specified as the directory.
map Names a map that the autofsmount command uses to find the mount points
and locations. This can either be a file name, an NIS map name, or a
special map name.
If you do not specify a full pathname (see directory) with the map
parameter, the autofsmount command attempts to open the specified map
as a local master map file. If this attempt fails, the command then
attempts to obtain the specified map from NIS.
-mount-options
Specifies the mount options to be applied to all of the directories
listed in map. If mount options are listed in the specified map, they
take precedence over these options.
DESCRIPTION
The autofsmount command installs and removes intercept points that are used
by the kernel to automatically and transparently mount and unmount NFS file
systems. It also removes file systems that were NFS-mounted by the autofsd
daemon, if necessary.
You can specify AutoFS intercept points in the form of map files.
Maps
Conventionally, AutoFS maps are files that are located in the /etc
directory with names that have the prefix auto. They indicate which remote
file systems to mount, where to mount them, and which options to use.
An individual AutoFS map is either local or served by NIS. A system,
however, can use both local and NIS AutoFS maps. When a map is referenced,
the autofsmount command checks whether a full pathname is specified. If it
is, autofsmount looks for the designated mapname locally. If the mapname
is not a full pathname, autofsmount looks for an NIS map by that name.
The Master Map
The autofsmount program can consult a master map, which contains entries
that point to other maps that can be either direct or indirect. If NIS is
running, autofsmount checks for the presence of an NIS map named
auto.master; you are not required to run NIS or have an auto.master map. A
master map can also be a file whose location is specified with the -f
command line option.
The master map provides AutoFS with a list of maps, and with arguments that
pertain to each of the maps. Each line in the master map has the following
syntax:
directory map [mount-options]
directory
Specifies the full pathname of a local directory if the map argument is
the name of an indirect map or the name of a special map. If the map
argument is the name of a direct map, the dummy directory "/-" is
specified as the directory.
map Names a map that the autofsmount command uses to find the mount points
and locations. This can either be a file name, an NIS map name, or a
special map name.
mount-options
Lists the options used to regulate the mounting of entries listed in
map.
Direct Maps
Direct maps specify which remote file systems to mount locally and what the
local mount points are. They also can specify mount options. Direct maps
have the following syntax:
key [mount-options] location
key Specifies the full pathname of the mount point.
mount-options
Lists the options for this specific mount. When present, these options
override any mount options specified on the command line or in the
master map.
location
Specifies the location of the resource being mounted and uses the
format server:pathname. Multiple location fields can be specified; see
Replicated File Systems for more information.
Indirect Maps
Indirect maps have the same format as direct maps. However, unlike the key
in a direct map, the key in an indirect map is a simple name that does not
begin with a slash. (Remember that the indirect map as a whole has been
associated with a directory specified in the master map or on the command
line. The entries in an indirect map list subdirectories that are
individually mounted within the directory associated with the map.)
Special Maps
The -hosts map is a special AutoFS map that is used to access all
directories exported by a server to a client.
The following command allows a client to access directories that are
exported from any host in its /etc/hosts file, the NIS hosts database:
# autofsmount /net -hosts
For example, suppose that hera and sheba are both hosts on a local area
network that is running NIS. If superuser on hera enters the autofsmount
/net -hosts command, users on hera can access any directories that sheba
exports to hera. All of the exported directories are mounted under
/net/sheba on hera.
The -null map, when indicated on the command line, cancels the map entry
associated with the directory indicated. You can use it to cancel a map
specified in the master map. For example, invoking the autofsmount command
in the following manner causes the /net entry in auto.master to be ignored:
# autofsmount /net -null
This syntax applies only to entries in a master map or a direct map. For
indirect maps, you must specify the excluded entries by using the -null
option with the autofsd daemon. See autofsd(8).
Pattern Matching
The ampersand (&) is expanded into the key field in a map wherever it
appears. In the following example, the ampersand (&) expands to oak:
#key mount_options location
#
oak &:/export/&
The asterisk (*), when supplied as the key field, is recognized as the
catch-all entry. It is used to substitute for lines that are all formatted
similarly. Any entry following the asterisk is ignored. In the following
example, the autofsmount program uses the asterisk to match any host name
other than oak:
#key mount_options location
#
oak &:/export/&
* &:/home/&
Environment Variables
The value of an environment variable can be used within an AutoFS map by
prefixing a dollar sign ($) to its name. You can also use braces to
delimit the name of the variable from appended letters or digits. The
environment variables can be inherited from the environment or can be
explicitly defined with the -D command line option.
Multiple Mounts
A multiple mount entry causes several NFS mount points to be mounted and
unmounted together. Multiple mounts have the following syntax:
key mountpoint [mount-options] location...\
[mountpoint [mount-options] location...] ...
key Specifies the full pathname or simple name of the mount point,
depending on whether it is a direct or indirect map entry.
mountpoint
Specifies the full pathname of a local directory. All mount points must
begin with a slash (/). A slash is acceptable as the first mountpoint.
mount-options
Lists the options for this specific mount. When present, these options
override any mount options specified on the command line or in the
master map.
location
Specifies the location of the resource being mounted and uses the
format server:pathname. Multiple location fields can be specified; see
Replicated File Systems for more information.
If multiple mounts are hierarchically related, the order in which they
appear in the entry is the order in which they are mounted.
In the following example, the directories /usr/local, /usr/local/bin,
/usr/local/src, and /usr/local/tools are mounted from the machines host1,
host2, host3, and host4, respectively. When the root of the hierarchy is
referenced, the AutoFS mounts the whole hierarchy.
/usr/local \
/ -ro host1:/usr/local \
/bin -ro host2:/usr/local/bin \
/src -ro host3:/usr/local/src \
/tools -ro host4:/usr/src/tools
Readability has been improved by splitting the entry into five lines and
indenting the continuation lines.
Replicated File Systems
You can specify multiple locations for a single mount. If a file system is
located on several servers and one of the servers is disabled, the file
system can be mounted from one of the other servers. This makes sense only
when mounting a read-only file system.
In the following example, the reference pages can be mounted from host1,
machine2, or system3:
/usr/man\
-ro,soft host1:/usr/man \
machine2:/usr/man \
system3:/usr/man
The preceding example can also be expressed as a list of servers, separated
by commas and followed by a colon and the pathname, for example:
/usr/man -ro,soft host1,machine2,system3:/usr/man
This syntax is valid only if the pathname is the same on each server.
When you try to access the reference pages, the autofsd daemon first
classifies each of the specified servers based on the proximity of its
network address to the current system (Local, Same Subnet, Same Network, or
Other Network). The daemon then attempts to serve the file system from the
closest resource, starting with Local addresses.
If the file system can be served locally, the daemon uses a symbolic link
to access it. If the file system cannot be served locally, the daemon
resorts to trying all Same Subnet, Same Network, and Other Network
addresses, in that order. Except when checking Local addresses, the system
issues a ping request to each server concurrently and selects the first
server that responds to serve the file system.
RESTRICTIONS
Shell filename expansion does not apply to objects that are not currently
mounted.
You cannot update direct map entries while an active NFS file system is
mounted on the designated mount point. You must unmount the NFS file system
before the AutoFS mount-update takes effect.
AutoFS does not support shared mounts, as defined in automount(8).
AutoFS does not support map entries that meet all of the following
conditions: the directory to be mounted is locally served, no external
server is specified for the directory, and the source and target
directories would result in circular symbolic links on the system.
Furthermore, if the directory to be mounted is one of several
hierarchically-related map entries, which are normally mounted and
unmounted as a group, the group semantic is lost. The file systems are
mounted and unmounted on an individual basis. The autofsmount command
prints a warning message when it detects these conditions.
EXAMPLES
1. The following is a sample auto.master map:
#
# mount-point mapname mount-options
#
/net -hosts
/home auto.indirect -rw
/- auto.direct -ro,intr
2. The following is a typical AutoFS indirect map:
#
# key mount-options location
#
john merge:/usr/staff/john
mary stripe:/usr/staff/mary
fred blur:/usr/staff/fred
3. The following is a typical AutoFS direct map:
#
# key mount-options location
#
/usr/source -ro merge:/usr/src/proto
/usr/local blur:/usr/bin/tools
4. The following is a sample indirect map that specifies multiple mount
locations for the file system reference. The file system is mounted
from the first server to respond to the mount request.
reference -ro earl:/usr/src/ref\
fern:/usr/staff/ron/ref\
irv:/usr/backup/reference
ENVIRONMENT VARIABLES
AUTOFSMOUNT_EXPARGS
Specifies arguments for use with the -e option to the autofsmount
command. As a convenience, this environment variable can be used to
hold the value of the AUTOFSMOUNT_ARGS variable as defined in the
/etc/rc.config.common file. You can arrange for this by adding the
appropriate statements to the configuration file for your shell, as
follows.
For C Shell (in .cshrc file):
setenv AUTOFSMOUNT_EXPARGS `rcmgr -c get AUTOFSMOUNT_ARGS`
For Korn Shell (in .profile file):
AUTOFSMOUNT_EXPARGS=`rcmgr -c get AUTOFSMOUNT_ARGS`
export AUTOFSMOUNT_EXPARGS
With the environment variable set in this manner, you can invoke the
autofsmount command with all of your predefined options as follows:
# autofsmount -e
If necessary, you can include additional options after the -e option.
SEE ALSO
Commands: autofsd(8), automount(8), mount(8)
Network Administration: Services
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