AUTO.MASTER(5) manual page
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auto.master - Master Map for automounter
The auto.master map
is consulted to set up automount managed mount points when the autofs(8)
script is invoked or the automount(8)
program is run. Each line describes
a mount point and refers to an autofs map describing file systems to be
mounted under the mount point.
The default location of the master map is
/etc/auto.master but an alternate name may be given on the command line
when running the automounter and the default master map may changed by
setting the MASTER_MAP_NAME configuration variable in /etc/autofs. If
the master map name has no path then the system Name Service Switch configuration
will be consulted and each of the sources searched in line with the rules
given in the Name Service Switch configuration.
Access to mounts in maps
is governed by a key.
For direct maps the mount point is always specified
as:
/-
and the key used within the direct map is the full path to the mount
point. The direct map may have multiple entries in the master map.
For indirect
maps access is by using the path scheme:
/mount-point/key
where mount-point
is one of the entries listed in the master map. The key is a single directory
component and is matched against entries in the map given in the entry
(See autofs(5)
).
Additionally, a map may be included from its source as
if it were itself present in the master map by including a line of the
form:
+[maptype[,format]:]map [options]
and automount(8)
will process the
map according to the specification described below for map entries. Indirect
map entries must be unique in the master map so second and subsequent entries
for an indirect mount point are ignored by automount(8)
.
Master map
entries have three fields separated by an arbitrary number of spaces or
tabs. Lines beginning with # are comments. The first field is the mount point
described above and the second field is the name of the map to be consulted
for the mount point followed by the third field which contains options
to be applied to all entries in the map.
The format of a master map entry
is:
- mount-point [map-type[,format]:]map [options]
- mount-point
- Base location
for the autofs filesystem to be mounted. For indirect maps this directory
will be created (as with mkdir -p) and is removed when the autofs filesystem
is umounted.
- map-type
- Type of map used for this mount point. The following
are valid map types:
- file
- The map is a regular text file.
- program
- The map
is an executable program, which is passed a key on the command line and
returns an entry (everything besides the key) on stdout if successful. Optinally,
the keyword exec may be used as a synonym for program to avoid confusion
with amd formated maps mount type program.
- yp
- The map is a NIS (YP) database.
- nisplus
- The map is a NIS+ database.
- hesiod
- The map is a hesiod database
whose filsys entries are used for maps.
- ldap or ldaps
- The map is stored
in an LDAP directory. If ldaps is used the appropriate certificate must
be configured in the LDAP client.
- multi
- This map type allows the specification
of multiple maps separated by "--". These maps are searched in order to resolve
key lookups.
- dir
- This map type can be used at + master map including notation.
The contents of files under given directory are included to the master
map. The name of file to be included must be ended with ".autofs". A file
will be ignored if its name is not ended with the suffix. In addition a
dot file, a file which name is started with "." is also ignored.
- format
Format of the map data; currently the formats recognized are sun, which
is a subset of the Sun automounter map format, hesiod, for hesiod filesys
entries and amd for amd formated map entries. If the format is left unspecified,
it defaults to sun for all map types except hesiod unless it is a top level
amd mount that has a configuration entry for the mount point path, in which
case the format used is amd. - map
Name of the map to use. This is an absolute UNIX pathname for maps of types
file, dir, or program, and the name of a database in the case for maps
of type yp, nisplus, or hesiod or the dn of an LDAP entry for maps of type
ldap. - options
Any remaining command line arguments without leading dashes (-) are taken
as options (-o) to mount. Arguments with leading dashes are considered options
for the maps and are passed to automount (8)
.
The sun format supports the
following options:
- -Dvariable=value
- Replace variable with value in map substitutions.
- -strict
- Treat errors when mounting file systems as fatal. This is important
when multiple file systems should be mounted (‘multimounts’). If this option
is given, no file system is mounted at all if at least one file system
can’t be mounted.
- [no]browse
- This is an autofs specific option that is a
pseudo mount option and so is given without a leading dash. Use of the browse
option pre-creates mount point directories for indirect mount maps so the
map keys can be seen in a directory listing without being mounted. Use of
this option can cause performance problem if the indirect map is large
so it should be used with caution. The internal program default is to enable
browse mode for indirect mounts but the default installed configuration
overrides this by setting BROWSE_MODE to "no" because of the potential
performance problem.
- nobind
- This is an autofs specific option that is a
pseudo mount option and so is given without a leading dash. It may be used
either in the master map entry (so it effects all the map entries) or with
individual map entries to prevent bind mounting of local NFS filesystems.
For direct mount maps the option is only effective if specified on the
first direct map entry and is applied to all direct mount maps in the master
map. It is ignored if given on subsequent direct map entries. It may be used
on individual map entries of both types. Bind mounting of NFS file systems
can also be prevented for specific map entrys by adding the "port=" mount
option to the entries.
- symlink
- This option makes bind mounting use a symlink
instead of an actual bind mount. It is an autofs specific option that is
a pseudo mount option and so is given without a leading dash. It may be
used with indirect map entries only, either in the master map (so it effects
all map entries) or with individual map entries. The option is ignored for
direct mounts and non-root offest mount entries.
- -r, --random-multimount-selection
- Enables the use of ramdom selection when choosing a host from a list of
replicated servers. This option is applied to this mount only, overriding
the global setting that may be specified on the command line.
- -w, --use-weight-only
- Use only specified weights for server selection where more than one server
is specified in the map entry. If no server weights are given then each
available server will be tried in the order listed, within proximity.
- -t,
--timeout <seconds>
- Set the expire timeout for map entries. This option can
be used to override the global default given either on the command line
or in the configuration.
- -n, --negative-timeout <seconds>
- Set the timeout for
caching failed key lookups. This option can be used to override the global
default given either on the command line or in the configuration.
If "-hosts" is given as the map then accessing a key under the
mount point which corresponds to a hostname will allow access to the exports
of that host. The hosts map cannot be dynamically updated and requires a
HUP signal to be sent to the daemon for it to check hosts for an update.
Due to possible hierarchic dependencies within a mount tree, it might not
be completely updated during the HUP signal processing.
For example, with
an entry in the master map of /net -hosts accessing /net/myserver will
mount exports from myserver on directories below /net/myserver.
NOTE: mounts
done from a hosts map will be mounted with the "nosuid,nodev,intr" options
unless overridden by explicily specifying the "suid", "dev" or "nointr"
options in the master map entry.
If the map type ldap is specified
the mapname is of the form [//servername/]dn, where the optional servername
is the name of the LDAP server to query, and dn is the Distinguished Name
of a subtree to search for map entries. The old style ldap:servername:mapname
is also understood. Alternatively, the type can be obtained from the Name
Service Switch configuration, in which case the map name alone must be
given.
If no schema is set in the autofs configuration then autofs will
check each of the commonly used schema for a valid entry and if one is
found it will used for subsequent lookups.
There are three common schemas
in use:
- nisMap
Entries in the nisMap schema are nisObject objects in the specified subtree,
where the cn attribute is the key (the wildcard key is "/"), and the nisMapEntry
attribute contains the information used by the automounter. - automountMap
- The automountMap schema has two variations that differ in the attribute
used for the map key. Entries in the automountMap schema are automount objects
in the specified subtree, where the cn or automountKey attribute (depending
on local usage) is the key (the wildcard key is "/"), and the automountInformation
attribute contains the information used by the automounter. Note that the
cn attribute is case insensitive.
The object classes and attributes used
for accessing automount maps in LDAP can be changed by setting entries
in the autofs configuration located in /etc/autofs.conf.
- NOTE:
- If a schema
is given in the configuration then all the schema configuration values
must be set, any partial schema specification will be ignored.
- For amd format
maps a different schema is used:
- amdMap
The amdmap schema contains attributes amdmapName, amdmapKey and amdmapValue
where amdmapName contains the name of the containing map, amdmapKey contains
the map key and amdmapValue contains the map entry.
LDAP authenticated binds, TLS encrypted
connections and certification may be used by setting appropriate values
in the autofs authentication configuration file and configuring the LDAP
client with appropriate settings. The default location of this file is
/etc/autofs_ldap_auth.conf.
If this file exists it will be used to establish
whether TLS or authentication should be used.
An example of this file is:
<?xml version="1.0" ?>
<autofs_ldap_sasl_conf
usetls="yes"
tlsrequired="no"
authrequired="no"
authtype="DIGEST-MD5"
user="xyz"
secret="abc"
/>
If TLS encryption is to be used the location of the Certificate Authority
certificate must be set within the LDAP client configuration in order
to validate the server certificate. If, in addition, a certified connection
is to be used then the client certificate and private key file locations
must also be configured within the LDAP client.
In OpenLDAP these may be
configured in the ldap.conf file or in the per-user configuration. For example
it may be sensible to use the system wide configuration for the location
of the Certificate Authority certificate and set the location of the client
certificate and private key in the per-user configuration. The location of
these files and the configuration entry requirements is system dependent
so the documentation for your installation will need to be consulted to
get further information.
See autofs_ldap_auth.conf (5)
for more information.
/- auto.data
/home /etc/auto.home
/mnt yp:mnt.map
This will generate two mountpoints for /home and /mnt and install direct
mount triggers for each entry in the direct mount map auto.data. All accesses
to /home will lead to the consultation of the map in /etc/auto.home and
all accesses to /mnt will consult the NIS map mnt.map. All accesses to paths
in the map auto.data will trigger mounts when they are accessed and the
Name Service Switch configuration will be used to locate the source of
the map auto.data.
automount(8)
, autofs(5)
, autofs(8)
, autofs.conf(5)
,
autofs_ldap_auth.conf(5)
This manual page was written by Christoph
Lameter <chris@waterf.org>, for the Dean GNU/Linux system. Edited by <hpa@transmeta.com>
and Ian Kent <raven@themaw.net> .
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