unixdev.net


Switch to SpeakEasy.net DSL

The Modular Manual Browser

Home Page
Manual: (Debian-5.0)
Page:
Section:
Apropos / Subsearch:
optional field

AUTOFS(5)                     File Formats Manual                    AUTOFS(5)



AUTOFS(5)                     File Formats Manual                    AUTOFS(5)



NAME
       autofs - Format of the automounter maps

DESCRIPTION
       The  automounter  maps  are files or NIS maps referred to by the master
       map of the automounter  (see  auto.master(5)).   The  automounter  maps
       describe how file systems below the mountpoint of the map (given in the
       auto.master file) are to be mounted.  This describes the sun  map  for-
       mat;  if another map format is specified (e.g. hesiod), this documenta-
       tion does not apply.

       Maps can be changed on the fly and the automouter will recognize  those
       changes  on  the  next  operation it performs on that map.  This is not
       true for the auto.master map!

FORMAT
       This is a description of the text file format.  Other methods of speci-
       fying these files may exist.  All empty lines or lines beginning with #
       are ignored. The basic format of one line in such maps is:

       key [-options] location


   key
       For indirect mounts this is the part of the pathname between the mount-
       pointi  and the path into the filesystem mounted. Usually you can think
       about the key as a subdirectory name below the mountpoint.

       For direct mounts this is the full path of the mountpoint. This map  is
       always associated with the /- mountpoint in the master map.


   options
       Options  are  optional.   Options  can also be given in the auto.master
       file in which case both values are cumulative  (this  is  a  difference
       from SunOS).  The options are a list of comma separated options as cus-
       tomary for the mount(8) command. There are two special options -fstype=
       used  to  specify  a  filesystem  type  if the filesystem is not of the
       default NFS type.  This option is processed by the automounter and  not
       by  the  mount  command.  -strict is used to 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.


   location
       The location specifies from where the file system is to be mounted.  In
       the  most  cases  this  will  be  an  NFS volume and the usual notation
       host:pathname is used to indicate the remote filesystem and path to  be
       mounted.   If  the  filesystem  to  be mounted begins with a / (such as
       local /dev entries or smbfs shares) a :  needs  to  be  prefixed  (e.g.
       :/dev/sda1).

EXAMPLE
         kernel    -ro,soft,intr       ftp.kernel.org:/pub/linux
         boot      -fstype=ext2        :/dev/hda1
         windoze   -fstype=smbfs       ://windoze/c
         removable -fstype=ext2        :/dev/hdd
         cd        -fstype=iso9660,ro  :/dev/hdc
         floppy    -fstype=auto        :/dev/fd0
         server    -rw,hard,intr       / -ro myserver.me.org:/ \
                                       /usr myserver.me.org:/usr \
                                       /home myserver.me.org:/home

       In the first line we have a NFS remote mount of the kernel directory on
       ftp.kernel.org.  This is mounted read-only.  The second line mounts  an
       ext2  volume  on  a  local ide drive.  The third makes a share exported
       from a Windows machine available for automounting.  The rest should  be
       fairly  self-explanatory.  The  last entry (the last three lines) is an
       example of a multi-map (see below).

       If you use the automounter for a filesystem without access  permissions
       (like  vfat), users usually can't write on such a filesystem because it
       is mounted as user root.  You can solve this  problem  by  passing  the
       option  gid=<gid>,  e. g. gid=floppy. The filesystem is then mounted as
       group floppy instead of root. Then you can add the users to this group,
       and  they  can  write to the filesystem. Here's an example entry for an
       autofs map:

         floppy-vfat  -fstype=vfat,sync,gid=floppy,umask=002  :/dev/fd0


FEATURES
   Map Key Substitution
       An & character in the location is expanded to  the  value  of  the  key
       field  that  matched the line (which probably only makes sense together
       with a wildcard key).

   Wildcard Key
       A * in the key field of indirect maps matches all keys.  An example for
       the usefulness is the following entry:

         *         &:/home/&

       This  will  enable  you to access all the home directory of local hosts
       using the path /mountpoint/hostname/local-path.

   Variable Substitution
       The following special variables will be  substituted  in  the  key  and
       location  fields  of an automounter map if prefixed with $ as customary
       from shell scripts (Curly braces can be used  to  separate  the  field-
       name):

         ARCH           Architecture (uname -m)
         CPU            Processor Type
         HOST           Hostname (uname -n)
         OSNAME         Operating System (uname -s)
         OSREL          Release of OS (uname -r)
         OSVERS         Version of OS (uname -v)

       Additional  entries can be defined with the -Dvariable=Value map-option
       to automount(8).

   Executable Maps
       A map can be marked as executable.  The init  script  that  parses  the
       auto.master  map will pass this as a program map to the automounter.  A
       program map will be called as a script with the key as an argument.  It
       may return no lines of output if there's an error, or one or more lines
       containing a map (starting with the second column,  i.e.  omitting  the
       key, and quoting line breaks with \).

       To  use  a  program map, the automount(8) daemon has to be started with
       the program type instead of the file type.  This is implemented in  the
       initialization script.

       A  executable  map  can  return an errorcode to indicate the failure in
       addition to no output at all.  All output sent to stderr is logged into
       the system logs.

   Multiple Mounts
       A  multi-mount  map  can be used to name multiple filesystems to mount.
       It takes the form:

         key [-options] [mountpoint [-options] location...]...


       This may extend over multiple lines, quoting the line-breaks with  `\'.
       If  present,  the  per-mountpoint  mount-options  are  appended  to the
       default mount-options.

   Replicated Server
         Multiple replicated hosts, same path:
         <path> host1,host2,hostn:/path/path

         Multiple hosts, some with same path, some with another
         <path> host1,host2:/blah host3:/some/other/path

         Multiple replicated hosts, different (potentially) paths:
         <path> host1:/path/pathA host2:/path/pathB

         Mutliple weighted, replicated hosts same path:
         <path> host1(5),host2(6),host3(1):/path/path

         Multiple weighted, replicated hosts different (potentially) paths:
         <path> host1(3):/path/pathA host2(5):/path/pathB

         Anything else is questionable and unsupported, but these variations will also work:
         <path> host1(3),host:/blah


UNSUPPORTED
       This version of the automounter supports direct maps for FILE, NIS  and
       LDAP  maps  only and handles SunOS-style replicated filesystems only to
       the extent that mount(8) does.

CAVEATS
       Unlike Sun's multi-mount syntax, the mountpoint is  mandatory  for  all
       mounts.

SEE ALSO
       automount(8), auto.master(5), autofs(8), mount(8).

AUTHOR
       This  manual  page was written by Christoph Lameter <chrisATwaterf.org>,
       for the Debian GNU/Linux system.  Edited by H. Peter Anvin  <hpa@trans-
       meta.com>,   Jeremy   Fitzhardinge   <jeremyATgoop.org>   and  Ian  Kent
       <ravenATthemaw.net>.



                                  14 Jan 2000                        AUTOFS(5)