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AMD.CONF(5) File Formats Manual AMD.CONF(5)
NAME
amd.conf - Amd configuration file
SYNOPSIS
amd.conf
DESCRIPTION
The amd.conf file is the configuration file for Amd, as part of the am-
utils suite.
amd.conf contains runtime configuration information for the Amd
automounter program.
FILE FORMAT
The file consists of sections and parameters. A section begins with
the name of the section in square brackets and continues until the next
section begins or the end the file is reached. Sections contain
parameters of the form 'name = value'.
The file is line-based - that is, each newline-terminated line
represents either a comment, a section name or a parameter. No line-
continuation syntax is available.
Section, parameter names and their values are case sensitive.
Only the first equals sign in a parameter is significant. Whitespace
before or after the first equals sign is discarded. Leading, trailing
and internal whitespace in section and parameter names is irrelevant.
Leading and trailing whitespace in a parameter value is discarded.
Internal whitespace within a parameter value is not allowed, unless the
whole parameter value is quoted with double quotes as in 'name = "some
value"'.
Any line beginning with a pound sign (#) is ignored, as are lines
containing only whitespace.
The values following the equals sign in parameters are all either a
string (no quotes needed if string does not include spaces) or a
boolean, which may be given as yes/no. Case is significant in all
values. Some items such as cache timeouts are numeric.
SECTIONS
The [global] section
Parameters in this section either apply to Amd as a whole, or to all
other regular map sections which follow. There should be only one
global section defined in one configuration file.
It is highly recommended that this section be specified first in the
configuration file. If it is not, then regular map sections which
precede it will not use global values defined later.
Regular [/map] sections
Parameters in regular (non-global) sections apply to a single map
entry. For example, if the map section [/homes] is defined, then all
parameters following it will be applied to the /homes Amd-managed mount
point.
PARAMETERS
Parameters common to all sections
These parameters can be specified either in the global or a map
specific section. Entries specified in a map-specific section override
the default value or one defined in the global section. If such a
common parameter is specified only in the global section, it is
applicable to all regular map sections that follow.
browsable_dirs (string, default=no)
If "yes," then Amd's top-level mount points will be browsable to
readdir(3) calls. This means you could run for example ls(1)
and see what keys are available to mount in that directory. Not
all entries are made visible to readdir(3): the "/default"
entry, wildcard entries, and those with a "/" in them are not
included. If you specify "full" to this option, all but
"/default" will be visible. Note that if you run a command
which will attempt to stat(2) the entries, such as often done by
"ls -l" or "ls -F," Amd will attempt to mount every entry in
that map. This is often called a ``mount storm.''
map_defaults (string, default to empty)
This option sets a string to be used as the map's /defaults
entry, overriding any /defaults specified in the map. This
allows local users to override map defaults without modifying
maps globally.
map_options (string, default no options)
This option is the same as specifying map options on the command
line to Amd, such as "cache:=all".
map_type (string, default search all map types)
If specified, Amd will initialize the map only for the type
given. This is useful to avoid the default map search type used
by Amd which takes longer and can have undesired side-effects
such as initializing NIS even if not used. Possible values are
exec executable maps
file plain files
hesiod Hesiod name service from MIT
ldap Lightweight Directory Access Protocol
ndbm (New) dbm style hash files
nis Network Information Services (version 2)
nisplus Network Information Services Plus (version 3)
passwd local password files
union union maps
mount_type (string, default=nfs)
All Amd mount types default to NFS. That is, Amd is an NFS
server on the map mount points, for the local host it is running
on. If "autofs" is specified, Amd will be an autofs server for
those mount points.
autofs_use_lofs (string, default=yes)
When set to "yes" and using Autofs, Amd will use lofs-type
(loopback) mounts for type:=link mounts. This has the advantage
of mounting in place, and users get to the see the same pathname
that they chdir'ed into. If this option is set to "no," then
Amd will use symlinks instead: that code is more tested, but
negates autofs's big advantage of in-place mounts.
search_path (string, default no search path)
This provides a (colon-delimited) search path for file maps.
Using a search path, sites can allow for local map
customizations and overrides, and can distributed maps in
several locations as needed.
selectors_in_defaults (boolean, default=no)
If "yes," then the /defaults entry of maps will search for and
process any selectors before setting defaults for all other keys
in that map. Useful when you want to set different options for
a complete map based on some parameters. For example, you may
want to better the NFS performance over slow slip-based networks
as follows:
/defaults \
wire==slip-net;opts:=intr,rsize=1024,wsize=1024 \
wire!=slip-net;opts:=intr,rsize=8192,wsize=8192
Deprecated form: selectors_on_default
sun_map_syntax (boolean, default=no)
If "yes," then Amd will parse the map according to the Sun
Automount syntax.
Parameters applicable to the global section only
arch (string, default to compiled in value)
Same as the -A option to Amd. Allows you to override the value
of the arch Amd variable.
auto_attrcache (numeric, default=0)
Specify in seconds (or units of 0.1 seconds, depending on the
OS), what is the (kernel-side) NFS attribute cache timeout for
@i{Amd}'s own automount points. A value of 0 is supposed to
turn off attribute caching, meaning that @i{Amd} will be
consulted via a kernel-RPC each time someone stat()'s the mount
point (which could be abused as a denial-of-service attack).
Warning: some OSs are incapable of turning off the NFS attribute
cache reliably. On such systems, Amd may not work reliably
under heavy load. See the README.attrcache document in the Am-
utils distribution for more details.
auto_dir (string, default=/a)
Same as the -a option to Amd. This sets the private directory
where Amd will create sub-directories for its real mount points.
cache_duration (numeric, default=300)
Same as the -c option to Amd. Sets the duration in seconds that
looked-up or mounted map entries remain in the cache.
cluster (string, default no cluster)
Same as the -C option to Amd. Specifies the alternate HP-UX
cluster to use.
debug_mtab_file (string, default=/tmp/mnttab)
Path to mtab file that is used by Amd to store a list of mounted
file systems during debug-mtab mode. This option only applies
to systems that store mtab information on disk.
debug_options (string, default no debug options)
Same as the -D option to Amd. Specify any debugging options for
Amd. Works only if am-utils was configured for debugging using
the --enable-debug option. The "mem" option, as well as all
other options, can be turned on via --enable-debug=mem.
Otherwise debugging options are ignored. Options are comma
delimited, and can be preceded by the string "no" to negate
their meaning. You can get the list of supported debugging
options by running Amd -H. Possible values are:
all all options (excludes hrtime and mtab)
defaults "sensible" default options (all--excluding hrtime, mtab, and xdrtrace)
test full debug options plus mtab,nodaemon,nofork,noamq
amq register for amq
daemon enter daemon mode
fork fork server
full program trace
hrtime print high resolution time stamps (only if syslog(3) is not used)
info info service specific debugging (hesiod, nis, etc.)
mem trace memory allocations
mtab use local "/tmp/mtab" file
readdir show browsable_dirs progress
str debug string munging
trace trace protocol and NFS mount arguments
xdrtrace trace XDR routines
dismount_interval (numeric, default=120)
Same as the -w option to Amd. Specify in seconds, the time
between attempts to dismount file systems that have exceeded
their cached times.
domain_strip (boolean, default=yes)
If "yes," then the domain name part referred to by ${rhost} is
stripped off. This is useful to keep logs and smaller. If
"no," then the domain name part is left changed. This is useful
when using multiple domains with the same maps (as you may have
hosts whose domain-stripped name is identical).
exec_map_timeout (numeric, default=10)
The timeout in seconds that Amd will wait for an executable map
program before an answer is returned from that program (or
script). This value should be set to as small as possible while
still allowing normal replies to be returned before the timer
expires, because during the time that the executable map program
is queried, Amd is essentially waiting and is thus not
responding to any other queries.
forced_unmounts (boolean, default=no)
If set to "yes," and the client OS supports forced or lazy
unmounts, then Amd will attempt to use them if it gets any of
three serious error conditions when trying to unmount an
existing mount point or mount on top of one: EIO, ESTALE, or
EBUSY.
This could be useful to recover from serious conditions such as
hardware failure of mounted disks, or NFS servers which are down
permanently, were migrated, or changed their IP address. Only
"type:=toplvl" mounts hung with EBUSY are forcibly unmounted
using this option, which is useful to recover from a hung Amd).
full_os (string, default to compiled in value)
The full name of the operating system, along with its version.
Allows you to override the compiled-in full name and version of
the operating system. Useful when the compiled-in name is not
desired. For example, the full operating system name on linux
comes up as ``linux'', but you can override it to
``linux-2.2.5.''
fully_qualified_hosts (string, default=no)
If "yes," Amd will perform RPC authentication using fully-
qualified host names. This is necessary for some systems, and
especially when performing cross-domain mounting. For this
function to work, the Amd variable ${hostd} is used, requiring
that ${domain} not be null.
hesiod_base (string, default=automount)
Specify the base name for hesiod maps.
karch (string, default to karch of the system)
Same as the -k option to Amd. Allows you to override the
kernel-architecture of your system. Useful for example on Sun
(Sparc) machines, where you can build one Amd binary, and run it
on multiple machines, yet you want each one to get the correct
karch variable set (for example, sun4c, sun4m, sun4u, etc.)
Note that if not specified, Amd will use uname(3) to figure out
the kernel architecture of the machine.
ldap_base (string, default not set)
Specify the base name for LDAP. This often includes LDAP-
specific values such as country and organization.
ldap_cache_maxmem (numeric, default=131072)
Specify the maximum memory Amd should use to cache LDAP entries.
ldap_cache_seconds (numeric, default=0)
Specify the number of seconds to keep entries in the cache.
ldap_hostports (string, default not set)
Specify the LDAP host and port values.
ldap_proto_version (numeric, default=2)
Specify the version of the LDAP protocol to use.
local_domain (string, default no sub-domain)
Same as the -d option to Amd. Specify the local domain name.
If this option is not given the domain name is determined from
the hostname, by removing the first component of the fully-
qualified host name.
localhost_address (string, default to localhost or 127.0.0.1)
Specify the name or IP address for Amd to use when connecting
the sockets for the local NFS server and the RPC server. This
defaults to 127.0.0.1 or whatever the host reports as its local
address. This parameter is useful on hosts with multiple
addresses where you want to force Amd to connect to a specific
address.
log_file (string, default=/dev/stderr)
Same as the -l option to Amd. Specify a file name to log Amd
events to. If the string /dev/stderr is specified, Amd will
send its events to the standard error file descriptor. If the
string syslog is given, Amd will record its events with the
system logger syslogd(8). The default syslog facility used is
LOG_DAEMON. If you wish to change it, append its name to the
log file name, delimited by a single colon. For example, if
logfile is the string syslog:local7 then Amd will log messages
via syslog(3) using the LOG_LOCAL7 facility (if it exists on the
system).
log_options (string, default=defaults)
Same as the -x option to Amd. Specify any logging options for
Amd. Options are comma delimited, and can be preceded by the
string "no" to negate their meaning. The "debug" logging option
is only available if am-utils was configured with --enable-
debug. You can get the list of supported debugging and logging
options by running amd -H. Possible values are:
all all messages
defaults default messages (fatal,error,user,warning,info)
debug debug messages
error non-fatal system errors (cannot be turned off)
fatal fatal errors (cannot be turned off)
info information
map map errors
stats additional statistical information
user non-fatal user errors
warn warnings
warning warnings
map_reload_interval (numeric, default=3600)
The number of seconds that Amd will wait before it checks to see
if any maps have changed at their source (NIS servers, LDAP
servers, files, etc.). Amd will reload only those maps that
have changed.
nfs_allow_any_interface (string, default=no)
Normally Amd accepts local NFS packets only from 127.0.0.1. If
this parameter is set to "yes" then Amd will accept local NFS
packets from any local interface; this is useful on hosts that
may have multiple interfaces where the system is forced to send
all outgoing packets (even those bound to the same host) via an
address other than 127.0.0.1.
nfs_allow_insecure_port (string, default=no)
Normally Amd will refuse requests coming from unprivileged ports
(i.e. ports >= 1024 on Unix systems), so that only privileged
users and the kernel can send NFS requests to it. However, some
kernels (certain versions of Darwin, MacOS X, and Linux) have
bugs that cause them to use unprivileged ports in certain
situations, which causes Amd to stop dead in its tracks. This
parameter allows Amd to operate normally even on such systems,
at the expense of a slight decrease in the security of its
operations. If you see messages like "ignoring request from
foo:1234, port not reserved" in your Amd log, try enabling this
parameter and give it another go.
nfs_proto (string, default to trying version tcp then udp)
By default, Amd tries TCP and then UDP. This option forces the
overall NFS protocol used to TCP or UDP. It overrides what is
in the Amd maps, and is useful when Amd is compiled with NFSv3
support that may not be stable. With this option you can turn
off the complete usage of NFSv3 dynamically (without having to
recompile Amd) until such time as NFSv3 support is desired
again.
nfs_retransmit_counter (numeric, default=11)
Same as the retransmit part of the -t timeout.retransmit option
to Amd. Specifies the number of NFS retransmissions that the
kernel will use to communicate with Amd.
nfs_retransmit_counter_udp (numeric, default=11)
Same as the nfs_retransmit_counter option, but for all UDP
mounts only.
nfs_retransmit_counter_tcp (numeric, default=11)
Same as the nfs_retransmit_counter option, but for all TCP
mounts only.
nfs_retransmit_counter_toplvl (numeric, default=11)
Same as the nfs_retransmit_counter option, but only for Amd's
top-level UDP mounts.
nfs_retry_interval (numeric, default=8)
Same as the timeout part of the -t timeout.retransmit option to
Amd. Specifies the NFS timeout interval, in tenths of seconds,
between NFS/RPC retries (for UDP and TCP). This is the value
that the kernel will use to communicate with Amd.
Amd relies on the kernel RPC retransmit mechanism to trigger
mount retries. The values of the nfs_retransmit_counter and the
nfs_retry_interval parameters change the overall retry interval.
Too long an interval gives poor interactive response; too short
an interval causes excessive retries.
nfs_retry_interval_udp (numeric, default=8)
Same as the nfs_retry_interval option, but for all UDP mounts
only.
nfs_retry_interval_tcp (numeric, default=8)
Same as the nfs_retry_interval option, but for all TCP mounts
only.
nfs_retry_interval_toplvl (numeric, default=8)
Same as the nfs_retry_interval option, but only for Amd's top-
level UDP mounts.
nfs_vers (numeric, default to trying version 3 then 2)
By default, Amd tries version 3 and then version 2. This option
forces the overall NFS protocol used to version 3 or 2. It
overrides what is in the Amd maps, and is useful when Amd is
compiled with NFSv3 support that may not be stable. With this
option you can turn off the complete usage of NFSv3 dynamically
(without having to recompile Amd) until such time as NFSv3
support is desired again.
nis_domain (string, default to local NIS domain name)
Same as the -y option to Amd. Specify an alternative NIS domain
from which to fetch the NIS maps. The default is the system
domain name. This option is ignored if NIS support is not
available.
normalize_hostnames (boolean, default=no)
Same as the -n option to Amd. If "yes," then the name refereed
to by ${rhost} is normalized relative to the host database
before being used. The effect is to translate aliases into
``official'' names.
normalize_slashes (boolean, default=yes)
If "yes," then Amd will condense all multiple ``/'' (slash)
characters into one and remove all trailing slashes. If "no,"
then Amd will not touch strings that may contain repeated or
trailing slashes. The latter is sometimes useful with SMB
mounts, which often require multiple slash characters in
pathnames.
os (string, default to compiled in value)
Same as the -O option to Amd. Allows you to override the
compiled-in name of the operating system. Useful when the
built-in name is not desired for backward compatibility reasons.
For example, if the build in name is ``sunos5'', you can
override it to ``sos5'', and use older maps which were written
with the latter in mind.
osver (string, default to compiled in value)
Same as the -o option to Amd. Overrides the compiled-in version
number of the operating system. Useful when the built in
version is not desired for backward compatibility reasons. For
example, if the build in version is ``2.5.1'', you can override
it to ``5.5.1'', and use older maps that were written with the
latter in mind.
pid_file (string, default=/dev/stdout)
Specify a file to store the process ID of the running daemon
into. If not specified, Amd will print its process id onto the
standard output. Useful for killing Amd after it had run. Note
that the PID of a running Amd can also be retrieved via amq -p.
This file is used only if the print_pid option is on.
plock (boolean, default=yes)
Same as the -S option to Amd. If "yes," lock the running
executable pages of Amd into memory. To improve Amd's
performance, systems that support the plock(3) or mlockall(2)
call can lock the Amd process into memory. This way there is
less chance it the operating system will schedule, page out, and
swap the Amd process as needed. This improves Amd's
performance, at the cost of reserving the memory used by the Amd
process (making it unavailable for other processes).
portmap_program (numeric, default=300019)
Specify an alternate Port-mapper RPC program number, other than
the official number. This is useful when running multiple Amd
processes. For example, you can run another Amd in "test" mode,
without affecting the primary Amd process in any way. For
safety reasons, the alternate program numbers that can be
specified must be in the range 300019-300029, inclusive. Amq
has an option -P which can be used to specify an alternate
program number of an Amd to contact. In this way, amq can fully
control any number of Amd processes running on the same host.
preferred_amq_port (numeric, default=0)
Specify an alternate Port-mapper RPC port number for Amd's Amq
service. This is used for both UDP and TCP. Setting this value
to 0 (or not defining it) will cause Amd to select an arbitrary
port number. Setting the Amq RPC service port to a specific
number is useful in firewalled or NAT'ed environments, where you
need to know which port Amd will listen on.
print_pid (boolean, default=no)
Same as the -p option to Amd. If "yes," Amd will print its
process ID upon starting.
print_version (boolean, default=no)
Same as the -v option to Amd, but the version prints and Amd
continues to run. If "yes," Amd will print its version
information string, which includes some configuration and
compilation values.
restart_mounts (boolean, default=no)
Same as the -r option to Amd. If "yes" Amd will scan the mount
table to determine which file systems are currently mounted.
Whenever one of these would have been auto-mounted, Amd inherits
it.
show_statfs_entries (boolean), default=no)
If "yes," then all maps which are browsable will also show the
number of entries (keys) they have when "df" runs. (This is
accomplished by returning non-zero values to the statfs(2)
system call).
truncate_log (boolean), default=no)
If "yes," then the log file (if it is a regular file), will be
truncated upon startup.
unmount_on_exit (boolean), default=no)
If "yes," then Amd will attempt to unmount all file systems
which it knows about. Normally Amd leaves all (esp. NFS)
mounted file systems intact. Note that Amd does not know about
file systems mounted before it starts up, unless the
restart_mounts option or -r flag are used.
use_tcpwrappers (boolean), default=yes)
If "yes," then Amd will use the tcpd/librwap tcpwrappers library
(if available) to control access to Amd via the /etc/hosts.allow
and /etc/hosts.deny files.
vendor (string, default to compiled in value)
The name of the vendor of the operating system. Overrides the
compiled-in vendor name. Useful when the compiled-in name is
not desired. For example, most Intel based systems set the
vendor name to ``unknown'', but you can set it to ``redhat.''
Parameters applicable to regular map sections
map_name (string, must be specified)
Name of the map where the keys are located.
tag (string, default no tag)
Each map entry in the configuration file can be tagged. If no
tag is specified, that map section will always be processed by
Amd. If it is specified, then Amd will process the map if the
-T option was given to Amd, and the value given to that command-
line option matches that in the map section.
EXAMPLES
Here is a real Amd configuration file I use daily.
# GLOBAL OPTIONS SECTION
[ global ]
normalize_hostnames = no
print_pid = no
restart_mounts = yes
auto_dir = /n
log_file = /var/log/amd
log_options = all
#debug_options = all
plock = no
selectors_in_defaults = yes
# config.guess picks up "sunos5" and I don't want to edit my maps yet
os = sos5
# if you print_version after setting up "os," it will show it.
print_version = no
map_type = file
search_path = /etc/amdmaps:/usr/lib/amd:/usr/local/AMD/lib
browsable_dirs = yes
# DEFINE AN AMD MOUNT POINT
[ /u ]
map_name = amd.u
[ /proj ]
map_name = amd.proj
[ /src ]
map_name = amd.src
[ /misc ]
map_name = amd.misc
[ /import ]
map_name = amd.import
[ /tftpboot/.amd ]
tag = tftpboot
map_name = amd.tftpboot
SEE ALSO
amd(8), amq(8), ctl-amd(8), automount(8), hosts_access(5).
``am-utils'' info(1) entry.
Linux NFS and Automounter Administration by Erez Zadok, ISBN
0-7821-2739-8, (Sybex, 2001).
http://www.am-utils.org
Amd - The 4.4 BSD Automounter
AUTHORS
Erez Zadok <ezk@cs.sunysb.edu>, Computer Science Department, Stony
Brook University, Stony Brook, New York, USA.
Other authors and contributors to am-utils are listed in the AUTHORS
file distributed with am-utils.
7 August 1997 AMD.CONF(5)