конфигурация autofs (autofs configuration)
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_retransmit_counter_tcp, nfs_retransmit_counter_toplvl,
nfs_retry_interval, nfs_retry_interval_udp,
nfs_retry_interval_tcp, nfs_retry_interval_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
truncating 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 implemented 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
protocol 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 exception 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 browsing 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
options. When the log_options options is encountered it
is converted 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 always results in a non-functional
automount tree if mounts were busy at the last shutdown
(as is also the case with amd when using mount_type
autofs).
forced_unmounts
Detaching mounts often causes serious problems for users
of existing mounts. It is used by autofs in some cases,
either at the explicit request of the user (with a command
line or init option) 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 implementing 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 variation of this option, "browsable", can be used
as a pseudo mount option in type "auto" map entries to
provide browsing functionality in sub-mounts. The amd
"browsable_dirs = full" option cannot 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
corresponds 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 machines 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
multiple 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.
