AUTOFS.CONF(5) File Formats Manual AUTOFS.CONF(5)
NAME
autofs.conf - autofs configuration
DESCRIPTION
Configuration settings used by automount(8) may be changed in the con-
figuration file /etc/autofs.conf.
This file contains two primary sections, autofs and amd.
Configuration entries may be present at the beginning of the configura-
tion file without a section header and are implicitly included as part
of the autofs section.
Each section name is enclosed in square brackets with spaces between
the brackets and the section name. The amd section may be followed by
further sections, named by the top level mount point path, that contain
per mount configuration settings.
SECTION autofs CONFIGURATION OPTIONS
Configuration settings available are:
timeout
Sets the default mount timeout in seconds. The internal program
default is 10 minutes, but the default installed configuration
overrides this and sets the timeout to 5 minutes to be consis-
tent with earlier autofs releases.
master_wait
sets the default maximum time to wait for the master map to be-
come available if it cannot be read at program start (program
default 10, wait for 10 seconds then continue).
negative_timeout
Set the default timeout for caching failed key lookups (program
default 60). If the equivalent command line option is given it
will override this setting.
mount_verbose
Use the verbose flag when spawning mount(8), and log some
process info about the requestor and its parent (program default
"no").
mount_wait
Set the default time to wait for a response from a spawned
mount(8) before sending it a SIGTERM. Note that we still need to
wait for the RPC layer to timeout before the sub-process exits
so this isn't ideal but it is the best we can do. The default is
to wait until mount(8) returns without intervention.
umount_wait
Set the default time to wait for a response from a spawned
umount(8) before sending it a SIGTERM. Note that we still need
to wait for the RPC layer to timeout before the sub-process ex-
its so this isn't ideal but it is the best we can do.
browse_mode
Maps are browsable by default (program default "yes").
mount_nfs_default_protocol
Set the default protocol that mount.nfs(8) uses when performing
a mount (program default 3). Autofs needs to know the default
NFS protocol that mount.nfs(8) uses so it can do special case
handling for its availability probe for different NFS protocols.
Since we can't identify this default automatically we need to
set it in the autofs configuration.
append_options
Determine whether global options, given on the command line or
per mount in the master map, are appended to map entry options
or if the map entry options replace the global options (program
default "yes", append options).
logging
set default log level "none", "verbose" or "debug" (program de-
fault "none").
force_standard_program_map_env
override the use of a prefix with standard environment variables
when a program map is executed. Since program maps are run as
the privileged user setting these standard environment variables
opens automount(8) to potential user privilege escalation when
the program map is written in a language that can load compo-
nents from, for example, a user home directory (program default
"no").
map_hash_table_size
This configuration option may be used to change the number of
hash table slots (default 1024).
This configuration option affects the overhead of searching the
map entry cache for map entries when there are a large number of
entries. It affects the number of entries that must be looked
at to locate a map entry in the map entry cache. For example,
the default of 1024 and a direct map with 8000 entries would re-
sult in each slot containing an average of 8 entries, which
should be acceptable.
However, if excessive CPU usage is observed during automount
lookups increasing this option can reduce the CPU overhead con-
siderably because it reduces the length of the search chains.
Note that the number of entries in a map doesn't necessarily re-
late to the number of entries used in the map entry cache.
There are two distinct cases where the map hash table can make a
significant difference, direct maps and indirect maps that use
the "browse" option.
For indirect maps that do not use the "browse" option entries
are added to the map entry cache at lookup so the number of ac-
tive cache entries, in this case, is usually much less than the
number of entries in the map. In this last case it would be un-
usual for the map entry cache to grow large enough to warrant
increasing the default before an event that cleans stale en-
tries, a map re-read for example.
use_hostname_for_mounts
NFS mounts where the host name resolves to more than one IP ad-
dress are probed for availability and to establish the order in
which mounts to them should be tried. To ensure that mount at-
tempts are made only to hosts that are responding and are tried
in the order of hosts with the quickest response the IP address
of the host needs to be used for the mount.
If it is necessary to use the hostname given in the map entry
for the mount regardless, then set this option to "yes".
Be aware that if this is done there is no defense against the
host name resolving to one that isn't responding and while the
number of attempts at a successful mount will correspond to the
number of addresses the host name resolves to the order will
also not correspond to fastest responding hosts.
disable_not_found_message
The original request to add this log message needed it to be un-
conditional. That produces, IMHO, unnecessary noise in the log
so a configuration option has been added to provide the ability
to turn it off. The default is "no" to maintain the current be-
haviour.
use_ignore_mount_option
An option to enable the use of autofs pseudo option "disable".
This option is used as a hint to user space that the mount entry
should be omitted from mount table listings. The default is "no"
to avoid unexpected changes in behaviour and so is an opt-in
setting.
sss_master_map_wait
Set the time to wait and retry if sssd returns "no such entry"
when starting up. When sssd is starting up it can sometimes re-
turn "no such entry" for a short time until it has read in the
LDAP map information. Default is 0 seconds, don't wait.
use_mount_request_log_id
Set whether to use a mount request log id so that log entries
for specific mount requests can be easily identified in logs
that have multiple concurrent requests. Default is don't use
mount request log ids.
LDAP Configuration
Configuration settings available are:
ldap_timeout
Set the network response timeout (default 8). Set timeout value
for the synchronous API calls. The default is the LDAP library
default of an infinite timeout.
ldap_network_timeout
Set the network response timeout (default 8).
ldap_uri
A space separated list of server uris of the form
<proto>://<server>[/] where <proto> can be ldap or ldaps. The
option can be given multiple times. Map entries that include a
server name override this option and it is then not used. De-
fault is an empty list in which case either the server given in
a map entry or the LDAP configured default is used. This uri
list is read at startup and whenever the daemon receives a HUP
signal.
This configuration option can also be used to request autofs
lookup SRV RRs for a domain of the form <proto>:///[<domain
dn>]. Note that a trailing "/" is not allowed when using this
form. If the domain dn is not specified the dns domain name (if
any) is used to construct the domain dn for the SRV RR lookup.
The server list returned from an SRV RR lookup is refreshed ac-
cording to the minimum ttl found in the SRV RR records or after
one hour, whichever is less.
search_base
The base dn to use when searching for amap base dn. This entry
may be given multiple times and each will be checked for a map
base dn in the order they occur in the configuration. The search
base list is read at startup and whenever the daemon receives a
HUP signal.
map_object_class
The map object class. In the nisMap schema this corresponds to
the class nisMap and in the automountMap schema it corresponds
to the class automountMap.
entry_object_class
The map entry object class. In the nisMap schema this corre-
sponds to the class nisObject and in the automountMap schema it
corresponds to the class automount.
map_attribute
The attribute used to identify the name of the map to which this
entry belongs. In the nisMap schema this corresponds to the at-
tribute nisMapName and in the automountMap schema it corresponds
to the attribute ou or automountMapName.
entry_attribute
The attribute used to identify a map key. In the nisMap schema
this corresponds to the attribute cn and in the automountMap
schema it corresponds to the attribute automountKey.
value_attribute
The attribute used to identify the value of the map entry. In
the nisMap schema this corresponds to the attribute nisMapEntry
and in the automountMap schema it corresponds to the attribute
automountInformation.
NOTE: It is essential that entries use class and attribute in a con-
sistent manner for correct operation of autofs. For example mix-
ing cn and automountKey attributes in automount schema will not
work as expected.
auth_conf_file
This configuration option may be used to specify an alternate
location for the ldap authentication configuration file. See
autofs_ldap_auth.conf(5) for more information.
SECTION amd CONFIGURATION OPTIONS
A number of the amd configuration options are not used by autofs, some
because they are not relevant within autofs, some because they are done
differently in autofs and others that are not yet implemented.
Since mount_type is always autofs (because there's no user space NFS
server) the configuration entries relating to that aren't used. Also,
server availability is done differently within autofs so the options
that relate to the amd server monitoring sub-system are also not used.
These options are mount_type, auto_attrcache, portmap_program,
nfs_vers_ping, nfs_allow_any_interface, nfs_allow_insecure_port,
nfs_proto, nfs_retransmit_counter, nfs_retransmit_counter_udp, nfs_re-
transmit_counter_tcp, nfs_retransmit_counter_toplvl, nfs_retry_inter-
val, nfs_retry_interval_udp, nfs_retry_interval_tcp, nfs_retry_inter-
val_toplvl and nfs_vers.
Other options that are not used within the autofs implementation:
log_file, truncate_log
sends its output to syslog so an alternate log file (or truncat-
ing the log) can't be used.
print_pid
There's no corresponding option for this within autofs.
use_tcpwrappers, show_statfs_entries
There's no user space NFS server to control access to so this
option isn't relevant. The show_statfs_entries can't be imple-
mented for the same reason.
debug_mtab_file
There's no user space NFS server and autofs avoids using file
based mtab whenever possible.
sun_map_syntax
Sun map format is handled by autofs itself.
plock, show_statfs_entries, preferred_amq_port
Are not supported by autofs.
ldap_cache_maxmem, ldap_cache_seconds
External ldap caching is not used by autofs.
ldap_proto_version
autofs always attempts to use the highest available ldap proto-
col version.
cache_duration, map_reload_interval, map_options
The map entry cache is continually updated and stale entries
cleaned on re-load, which is done when map changes are detected
so these configuration entries are not used by autofs. An excep-
tion to this is the case where the map is large. In this case it
may be necessary to read the whole map at startup even if brows-
ing is not enabled. Adding the cache:=all option to map_options
can be used to for this.
localhost_address
This is not used within autofs. This configuration option was
only used in the amd user space server code and is not relevant
within autofs.
Options that are handled differently within autofs:
pid_file
To specify a pid file name a command line option must be used on
startup.
print_version
Program version and feature information is obtained by using the
automount command line option "-V".
debug_options , log_options
autofs has somewhat more limited logging and debug logging op-
tions. When the log_options options is encountered it is con-
verted to the nearest matching autofs logging option. Since the
configuration option debug_options would be handled the same way
it is ignored.
restart_mounts
This option has no sensible meaning within autofs because autofs
always tries to re-connect to existing mounts. While this has
its own set of problems not re-connecting to existing mounts al-
ways results in a non-functional automount tree if mounts were
busy at the last shutdown (as is also the case with amd when us-
ing mount_type autofs).
forced_unmounts
Detaching mounts often causes serious problems for users of ex-
isting mounts. It is used by autofs in some cases, either at the
explicit request of the user (with a command line or init op-
tion) and in some special cases during program operation but is
avoided whenever possible.
A number of configuration options are not yet implemented:
search_path
Always a little frustrating, the compiled in map location should
be used to locate maps but isn't in some cases. This requires
work within autofs itself and that will (obviously) include im-
plementing this configuration option for the amd map parser as
well.
fully_qualified_hosts
Not yet implemented.
unmount_on_exit
Since autofs always tries to re-connect to mounts left mounted
from a previous shutdown this is a sensible option to implement
and that will be done.
browsable_dirs
Allow map keys to be shown in directory listings. This option
can have values of "yes" or "no". The default is "no". A varia-
tion of this option, "browsable", can be used as a pseudo mount
option in type "auto" map entries to provide browsing function-
ality in sub-mounts. The amd "browsable_dirs = full" option can-
not be implemented within the current autofs framework and is
not supported.
exec_map_timeout
A timeout is not currently used for program maps but this might
be implemented in the future.
tag
The tag option is not implemented within autofs.
Supported options:
arch, karch, os, osver
These options default to what is returned from uname(2) and can
be overridden if required.
full_os
This option has no default and must be set in the configuration
if used in maps.
cluster
If not set defaults to the host domain name. This option corre-
sponds to the HP_UX cluster name (according to the amd source)
and is probably not used in Linux but is set anyway.
vendor This option has a default value of "unknown", it must be set in
the configuration if used in maps.
auto_dir
Is the base name of the mount tree used for external mounts that
are sometimes needed by amd maps. Its default value is "/a".
map_type
Specifies the autofs map source, such as file, nis, ldap etc.
and has no default value set.
map_defaults
This option is used to override /defaults entries within maps
and can be used to provide different defaults on specific ma-
chines without having to modify centrally managed maps. It is
empty by default.
search_path
Colon separated paths to search for maps that are not specified
as a full path.
dismount_interval
Is equivalent to the autofs timeout option. It is only possible
to use this with type "auto" mounts due to the way the autofs
kernel module performs expiry. It takes its default value from
the autofs internal default of 600 seconds.
autofs_use_lofs
If set to "yes" autofs will attempt to use bind mounts for type
"link" entries when possible (default is "yes").
nis_domain
Allows setting of a domain name other than the system default.
local_domain
Is used to override (or set) the host domain name.
normalize_hostnames
If set to "yes" then the contents of ${rhost} is translated in
its official host name.
domain_strip
If set to "yes" the domain name part of the host is stripped
when normalizing hostnames. This can be useful when using of the
same maps in a multiple domain environment.
normalize_slashes
This option is set to "yes" by default and will collapse multi-
ple unescaped occurrences of "/" to a single "/".
selectors_in_defaults, selectors_on_default
This option has a default value of "no". If set to "yes" then
any defaults entry will be checked for selectors to determine
the values to be used. selectors_in_defaults is the preferred
option to use.
ldap_base
iThis option has no default value. It must be set to the base dn
that is used for queries if ldap is to be used as a map source.
ldap_hostports
This option has no default value set. It must be set to the URI
of the LDAP server to be used for lookups when ldap is used as a
map source. It may contain a comma or space separated list of
LDAP URIs.
hesiod_base
Sets the base name used for hesiod map sources.
linux_ufs_mount_type
This is an additional configuration option for the autofs amd
format parser implementation.
There's no simple way to determine what the system default
filesystem is and am-utils needs to be continually updated to do
this and can easily get it wrong ayway. So allow it to be set in
the configuration.
EXAMPLE
[ autofs ]
timeout = 300
browse_mode = no
[ amd ]
dismount_interval = 300
map_type = nis
autofs_use_lofs = no
[ /expamle/mount ]
dismount_interval = 60
map_type = file
SEE ALSO
automount(8), auto.master(5), autofs_ldap_auth.conf(5).
AUTHOR
This manual page was written by Ian Kent <raven@themaw.net>.
23 Jan 2014 AUTOFS.CONF(5)