NAME

automount - install automatic mount points

SYNOPSIS

/usr/sbin/automount [ -t duration ] [ -v ]

AVAILABILITY

SUNWcsu

DESCRIPTION

automount is a command that installs autofs mount points and associates an automount map with each mount point. The autofs filesystem monitors attempts to access directories within it and notifies the automountd(1M) daemon. The daemon uses the map to locate a filesystem, which it then mounts at the point of reference within the autofs filesystem. You can assign a map to an autofs mount using an entry in the /etc/auto_master map or a direct map.

If the file system is not accessed within an appropriate interval (five minutes by default), the automountd daemon unmounts the file system.

The file /etc/auto_master determines the locations of all autofs mount points. By default, this file contains four entries:

# Master map for automounter
#
+auto_master
/net            -hosts           -nosuid
/home           auto_home
/xfn            -xfn

The +auto_master entry is a reference to an external NIS or NIS+ master map. If one exists, then its entries are read as if they occurred in place of the +auto_master entry. The remaining entries in the master file specify a directory on which an autofs mount will be made followed by the automounter map to be associated with it. Optional mount options, that follow the automounter map name, may be supplied for each entry. These options are used for any entries in the map that do not specify mount options explicitly. Security attributes may also follow the automounter map name. These consist of a semicolon separated list of security attributes to be associated with the map. See mount (1MTSOL)for a description of these security attributes. As with mount options, security attributes in /etc/auto_master are used for any entries in the map that do not specify security attributes explicitly. The security attribute list must be preceded by a -S flag to distinguish it from mount options. The automount command is usually run without arguments. It compares the entries /etc/auto_master with the current list of autofs mounts in /etc/mnttab and adds, removes or updates autofs mounts to bring the /etc/mnttab up to date with the /etc/auto_master. At boot time it installs all autofs mounts from the master map. Subsequently, it may be run to install autofs mounts for new entries in the master map or an direct map, or to perform unmounts for entries that have been removed.

OPTIONS

-t duration

Specify a duration, in seconds, that a file system is to remain mounted when not in use. The default is 5 minutes.

-v

Verbose mode. Notify of autofs mounts, unmounts or other nonessential information.

USAGE

Map Entry Format

A simple map entry (mapping) takes the form:

key [ -mount-options ] [ -Sattribute-list ] location . . .

where key is the full pathname of the directory to mount when used in a direct map, or the simple name of a subdirectory in an indirect map. mount-options is a commaseparated list of mount options, attribute-list is a list of security attributes, and location specifies a file system from which the directory may be mounted. In the case of a simple NFS mount, location takes the form:

host: pathname

host is the name of the host from which to mount the file system (it may be omitted if the pathname refers to a local device on which the filesystem resides) and pathname is the pathname of the directory to mount.

Replicated Filesystems

Multiple location fields can be specified for replicated NFS filesystems, in which case automount chooses a server with preference given to a server on the local subnet or net.

If each location in the list shares the same pathname then a single location may be used with a comma-separated list of hostnames:

hostname, hostname...: pathname

Requests for a server may be weighted, with the weighting factor appended to the server name as an integer in parentheses. Servers without a weighting are assumed to have a value of zero (most likely to be selected). Progressively higher values decrease the chance of being selected. In the example,

man -ro alpha,bravo,charlie(1),delta(4):/usr/man

hosts alpha and bravo have the highest priority; host delta, the lowest.

Note: Server proximity takes priority in the selection process. In the example above, if the server delta is on the same network segment as the client, but the others are on different network segments, then delta will be selected -- the weighting value is ignored. The weighting has effect only when selecting between servers with the same network proximity.

In cases where each server has a different export point, you can still apply the weighting. For example:

man -ro alpha:/usr/man bravo,charlie(1):/usr/share/man delta(3):/export/man

A mapping can be continued across input lines by escaping the NEWLINE with a ` \ ' (backslash). Comments begin with a '#' (number sign) and end at the subsequent NEWLINE.

Multiple servers should be of the same host type with compatible label ranges.

Map Key Substitution

The '&' (ampersand) character is expanded to the value of the key field for the entry in which it occurs. In this case:

jane

sparcserver:/home/&

the & expands to jane.

Wildcard Key

The '* '(asterisk) character, when supplied as the key field, is recognized as the catch-all entry. Such an entry will match any key not previously matched. For instance, if the following entry appeared in the indirect map for /config:

*

&:/export/config/&

this would allow automatic mounts in /config of any remote file system whose location could be specified as:

hostname:/export/config/hostname

Variable Substitution

Client specific variables can be used within an automount map. For instance, if $ HOST appeared within a map, automount would expand it to its current value for the client's host name. Supported variables are:

ARCH

The output of uname -m.

The architecture name.

For example "sun4"

CPU

The output of uname -p.

The processor type.

For example "sparc"

HOST

The output of uname -n.

The host name. For

example "biggles"

OSNAME

The output of uname -s.

The OS name. For

example "SunOS"

OSREL

The output of uname -r.

The OS release name.

For example "5.3"

OSVERS

The output of uname -v.

The OS version. For

example "beta1.0"

If a reference needs to be protected from affixed characters, you can surround the variable name with '{ }' (curly braces).

Multiple Mounts

A multiple mount entry takes the form:

key [-mount-options] [-Sattribute-list] [ [mountpoint] [-mount-options] [-Sattribute-list] location. . . ] . . .

The initial /[mountpoint ] is optional for the first mount and mandatory for all subsequent mounts. The optional mountpoint is taken as a pathname relative to the directory named by key. If mountpoint is omitted in the first occurrence, a mountpoint of / (root) is implied.

Given an entry in the indirect map for /src:

beta -ro \

     /               svr1,svr2:/export/src/beta \
     /1.0            svr1,svr2:/export/src/beta/1.0 \
     /1.0/man        svr1,svr2:/export/src/beta/1.0/man

automount would automatically mount /src/beta, /src/beta/1.0, and /src/beta/1.0/man, as needed, from either svr1 or svr2, whichever host is nearest and responds first.

Other Filesystem Types

The automounter assumes NFS mounts as a default filesystem type. Other filesystem types can be described using the fstype mount option. Other mount options specific to this filesystem type can be combined with the fstype option. The location field must contain information specific to the filesystem type. If the location field begins with a slash, a colon character must be prepended, for instance, to mount a CD filesystem:

        cdrom -fstype=hsfs,ro      :/dev/sr0
or to perform an autofs mount:
        src    -fstype=autofs      auto_src

Mounts using CacheFS are most useful when applied to an entire map as map defaults. The following entry in the master map describes cached home directory mounts. It assumes the default location of the cache directory, /cache.

/home auto_home

-fstype=cachefs,backfstype=nfs

Indirect Maps

An indirect map allows you to specify mappings for the subdirectories you wish to mount under the directory indicated on the command line. In an indirect map, each key consists of a simple name that refers to one or more filesystems that are to be mounted as needed.

Direct Maps

Entries in a direct map are associated directly with autofs mount points. Each key is the full pathname of an autofs mount point. The direct map as a whole is not associated with any single directory.

Included Maps

The contents of another map can be included within a map with an entry of the form

+mapname

If mapname begins with a slash then it is assumed to be the pathname of a local file. Otherwise the location of the map is determined by the policy of the name service switch according to the entry for the automounter in /etc/nsswitch.conf, such as

automount: files nis

If the name service is files then the name is assumed to be that of a local file in /etc. If the key being searched for is not found in the included map, the search continues with the next entry.

Special Maps

There are three special maps available: -hosts, -xfn ,and -null. The -hosts map is used with the /net directory and assumes that the map key is the hostname of an NFS server. The automountd daemon dynamically constructs a map entry from the server's list of exported filesystems. For instance a reference to /net/hermes/usr would initiate an automatic mount of all exported file systems from hermes that are mountable by the client. References to a directory under /net/hermes will refer to the corresponding directory relative to hermes root.

The -xfn map is used to mount the initial context of the Federated Naming Service (FNS) namespace under the /xfn directory. For more information on FNS, see fns(5), fns_initial_context(5), fns_policies(5), and the Federated Naming Service Guide.

The -null map, when indicated on the command line, cancels a previous map for the directory indicated. This is most useful in the /etc/auto_master for cancelling entries that would otherwise be inherited from the +auto_master include entry. To be effective, the -null entries must be inserted before the included map entry.

Executable Maps

Local maps that have the execute bit set in their file permissions will be executed by the automounter and provided with a key to be looked up as an argument. The executable map is expected to return the content of an automounter map entry on its stdout or no output if the entry cannot be determined.

Configuration and the auto_master Map

When initiated without arguments, automount consults the master map for a list of autofs mount points and their maps. It mounts any autofs mounts that are not already mounted, and unmounts autofs mounts that have been removed from the master map or direct map.

The master map is assumed to be called auto_master and its location is determined by the name service switch policy. Normally the master map is located initially as a local file /etc/auto_master.

SUMMARY OF TRUSTED

Security attributes can be specified in auto_master and in autofs map entries with the -S option. If security attributes are not specified in either auto_master or an autofs map entry, but an entry for the mount point is in /etc/security/tsol/vfstab_adjunct, then security attributes in the vfstab_adjunct file are used.

SOLARIS CHANGES

automount must be started as root, with a process sensitivity label of ADMIN_LOW, and a clearance of ADMIN_HIGH. It must have the PAF_TRUSTED_PATH process attribute, and must inherit the following privileges: file_mac_read, file_mac_write, file_dac_read, file_dac_write, proc_nofloat, sys_mount.

FILES

/etc/auto_master

master automount map.

/etc/auto_home

map to support automounted home directories.

/etc/nsswitch.conf

the name service switch configuration file.

/etc/security/tsol/vfstab_adjunct mount-time attributes for file systems.

SEE ALSO

automountd(1M), mount (1MTSOL),vfstab_adjunct(4TSOL), fns(5), fns_initial_context(5), fns_policies(5),

NFS Administration Guide

NOTES

The -hosts map must mount all of the exported NFS filesystems from a server. If frequent access to just a single filesystem is required, it is more efficient to access the filesystem with a map entry that is tailored to mount just the filesystem of interest.

Autofs mount points must not be hierarchically related. automount does not allow an autofs mount point to be created within another autofs mount.

Since each direct map entry results in a new autofs mount such maps should be kept short.

If a directory contains direct map mount points then an ls -l in the directory will force all the direct map mounts to occur.

Entries in both direct and indirect maps can be modified at any time. The new information is used when automountd next uses the map entry to do a mount.

New entries added to a master map or direct map will not be useful until the automount command is run to install them as new autofs mount points. New entries added to an indirect map may be used immediately.

An autofs directory associated with an indirect map shows only currently-mounted entries. This is a deliberate policy to avoid inadvertent mounting of every entry in a map via an ls -l of the directory.

The multiple location feature for NFS mounts allows the automountd daemon to choose the most appropriate server at mount time. While such a mount is in effect, the daemon does not monitor the status of the server. If the server crashes, automountd will not select an alternative server from the list.

Default mount options and security attributes can be assigned to an entire map when they follow the automounter map name. These options apply only to map entries that have no mount options or security attributes.

The Network Information Service (NIS) was formerly known as Sun Yellow Pages (YP). The functionality of the two remains the same.