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/default/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:


   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]

          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.

          Type  of map used for this mount point.  The following are valid
          map types:

          file   The map is a regular text file.

                 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

          yp     The map is a NIS (YP) database.

                 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 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.

          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.

          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:

                 Replace variable with value in map substitutions.

                 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

                 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.

                 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

          -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

   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

   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:

          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.

          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/default/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:

          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

   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" ?>

   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

   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.


     /home     /etc/auto.home

   This will generate two mountpoints  for  /home  and  /mnt  and  install
   direct mount triggers for each entry in the direct mount map
   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  All accesses to paths  in  the  map  will  trigger
   mounts when they are accessed and the Name Service Switch configuration
   will be used to locate the source of the map


   automount(8),       autofs(5),        autofs(8),        autofs.conf(5),


   This  manual  page was written by Christoph Lameter <>,
   for the Debian GNU/Linux system.  Edited by <> and Ian
   Kent <> .

                              11 Apr 2006                   AUTO.MASTER(5)


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