This is amdref.info, produced by makeinfo version 4.2 from
/usr/src/usr.sbin/amd/doc/amdref.texinfo.

INFO-DIR-SECTION Miscellaneous
START-INFO-DIR-ENTRY
* Amdref: (amdref).                 4.4 BSD Automounter Reference Manual
END-INFO-DIR-ENTRY


File: amdref.info,  Node: /vol,  Prev: rwho servers,  Up: Examples

`/vol'
======

   `/vol' is used as a catch-all for volumes which do not have other
conventional names.

   Below is part of the `/vol' map for the domain `doc.ic.ac.uk'.  The
`r+d' tree is used for new or experimental software that needs to be
available everywhere without installing it on all the fileservers.
Users wishing to try out the new software then simply include
`/vol/r+d/{bin,ucb}' in their path.

   The main tree resides on one host `gould.doc.ic.ac.uk', which has
different `bin', `etc', `lib' and `ucb' sub-directories for each
machine architecture.  For example, `/vol/r+d/bin' for a Sun-4 would be
stored in the sub-directory `bin/sun4' of the filesystem `/usr/r+d'.
When it was accessed a symbolic link pointing to
`/a/gould/usr/r+d/bin/sun4' would be returned.

     /defaults    type:=nfs;opts:=rw,grpid,nosuid,intr,soft
     wp           -opts:=rw,grpid,nosuid;rhost:=charm \
                  host==charm;type:=link;fs:=/usr/local/wp \
                  host!=charm;type:=nfs;rfs:=/vol/wp
     ...
     #
     src          -opts:=rw,grpid,nosuid;rhost:=charm \
                  host==charm;type:=link;fs:=/usr/src \
                  host!=charm;type:=nfs;rfs:=/vol/src
     #
     r+d          type:=auto;fs:=${map};pref:=r+d/
     # per architecture bin,etc,lib&ucb...
     r+d/bin      rhost:=gould.doc.ic.ac.uk;rfs:=/usr/r+d;sublink:=${/key}/${arch}
     r+d/etc      rhost:=gould.doc.ic.ac.uk;rfs:=/usr/r+d;sublink:=${/key}/${arch}
     r+d/include  rhost:=gould.doc.ic.ac.uk;rfs:=/usr/r+d;sublink:=${/key}
     r+d/lib      rhost:=gould.doc.ic.ac.uk;rfs:=/usr/r+d;sublink:=${/key}/${arch}
     r+d/man      rhost:=gould.doc.ic.ac.uk;rfs:=/usr/r+d;sublink:=${/key}
     r+d/src      rhost:=gould.doc.ic.ac.uk;rfs:=/usr/r+d;sublink:=${/key}
     r+d/ucb      rhost:=gould.doc.ic.ac.uk;rfs:=/usr/r+d;sublink:=${/key}/${arch}
     # hades pictures
     pictures     -opts:=rw,grpid,nosuid;rhost:=thpfs \
                  host==thpfs;type:=link;fs:=/nbsd/pictures \
                  host!=thpfs;type:=nfs;rfs:=/nbsd;sublink:=pictures
     # hades tools
     hades        -opts:=rw,grpid,nosuid;rhost:=thpfs \
                  host==thpfs;type:=link;fs:=/nbsd/hades \
                  host!=thpfs;type:=nfs;rfs:=/nbsd;sublink:=hades
     # bsd tools for hp.
     bsd          -opts:=rw,grpid,nosuid;arch==hp9000;rhost:=thpfs \
                  host==thpfs;type:=link;fs:=/nbsd/bsd \
                  host!=thpfs;type:=nfs;rfs:=/nbsd;sublink:=bsd


File: amdref.info,  Node: Internals,  Next: Acknowledgements & Trademarks,  Prev: Examples,  Up: Top

Internals
*********

* Menu:

* Log Messages::


File: amdref.info,  Node: Log Messages,  Prev: Internals,  Up: Internals

Log Messages
============

   In the following sections a brief explanation is given of some of the
log messages made by Amd.  Where the message is in `typewriter' font,
it corresponds exactly to the message produced by Amd.  Words in
"italic" are replaced by an appropriate string.  Variables, `${var}',
indicate that the value of the appropriate variable is output.

   Log messages are either sent direct to a file, or logged via the
syslog(3) mechanism.  Messages are logged with facility `LOG_DAEMON'
when using syslog(3).  In either case, entries in the file are of the
form:
     date-string  hostname amd[pid]  message

* Menu:

* Fatal errors::
* Info messages::


File: amdref.info,  Node: Fatal errors,  Next: Info messages,  Prev: Log Messages,  Up: Log Messages

Fatal errors
------------

   Amd attempts to deal with unusual events.  Whenever it is not
possible to deal with such an error, Amd will log an appropriate
message and, if it cannot possibly continue, will either exit or abort.
These messages are selected by `-x fatal' on the command line.  When
syslog(3) is being used, they are logged with level `LOG_FATAL'.  Even
if Amd continues to operate it is likely to remain in a precarious
state and should be restarted at the earliest opportunity.

Attempting to inherit not-a-filesystem
     The prototype mount point created during a filesystem restart did
     not contain a reference to the restarted filesystem.  This erorr
     "should never happen".

Can't bind to domain "NIS-domain"
     A specific NIS domain was requested on the command line, but no
     server for that domain is available on the local net.

Can't determine IP address of this host (hostname)
     When Amd starts it determines its own IP address.  If this lookup
     fails then Amd cannot continue.  The hostname it looks up is that
     obtained returned by gethostname(2) system call.

Can't find root file handle for automount point
     Amd creates its own file handles for the automount points.  When it
     mounts itself as a server, it must pass these file handles to the
     local kernel.  If the filehandle is not obtainable the mount point
     is ignored.  This error "should never happen".

Must be root to mount filesystems (euid = euid)
     To prevent embarrassment, Amd makes sure it has appropriate system
     privileges.  This amounts to having an euid of 0.  The check is
     made after argument processing complete to give non-root users a
     chance to access the "-v" option.

No work to do - quitting
     No automount points were given on the command line and so there is
     no work to do.

Out of memory in realloc
     While attempting to realloc some memory, the memory space
     available to Amd was exhausted.  This is an unrecoverable error.

Out of memory
     While attempting to malloc some memory, the memory space available
     to Amd was exhausted.  This is an unrecoverable error.

cannot create rpc/udp service
     Either the NFS or AMQ endpoint could not be created.

gethostname: description
     The gethostname(2) system call failed during startup.

host name is not set
     The gethostname(2) system call returned a zero length host name.
     This can happen if Amd is started in single user mode just after
     booting the system.

ifs_match called!
     An internal error occurred while restarting a pre-mounted
     filesystem.  This error "should never happen".

mount_afs: description
     An error occured while Amd was mounting itself.

run_rpc failed
     Somehow the main NFS server loop failed.  This error "should never
     happen".

unable to free rpc arguments in amqprog_1
     The incoming arguments to the AMQ server could not be free'ed.

unable to free rpc arguments in nfs_program_1
     The incoming arguments to the NFS server could not be free'ed.

unable to register (AMQ_PROGRAM, AMQ_VERSION, udp)
     The AMQ server could not be registered with the local portmapper
     or the internal RPC dispatcher.

unable to register (NFS_PROGRAM, NFS_VERSION, 0)
     The NFS server could not be registered with the internal RPC
     dispatcher.


File: amdref.info,  Node: Info messages,  Prev: Fatal errors,  Up: Log Messages

Info messages
-------------

   Amd generates information messages to record state changes.  These
messages are selected by `-x info' on the command line.  When syslog(3)
is being used, they are logged with level `LOG_INFO'.

   The messages listed below can be generated and are in a format
suitable for simple statistical analysis.  "mount-info" is the string
that is displayed by "Amq" in its mount information column and placed
in the system mount table.

mount of "${path}" on ${fs} timed out
     Attempts to mount a filesystem for the given automount point have
     failed to complete within 30 seconds.

"${path}" forcibly timed out
     An automount point has been timed out by the Amq command.

restarting mount-info on ${fs}
     A pre-mounted file system has been noted.

"${path}" has timed out
     No access to the automount point has been made within the timeout
     period.

file server ${rhost} is down - timeout of "${path}" ignored
     An automount point has timed out, but the corresponding file
     server is known to be down.  This message is only produced once
     for each mount point for which the server is down.

Re-synchronizing cache for map ${map}
     The named map has been modified and the internal cache is being
     re-synchronized.

Filehandle denied for "${rhost}:${rfs}"
     The mount daemon refused to return a file handle for the requested
     filesystem.

Filehandle error for "${rhost}:${rfs}": description
     The mount daemon gave some other error for the requested
     filesystem.

file server ${rhost} type nfs starts up
     A new NFS file server has been referenced and is known to be up.

file server ${rhost} type nfs starts down
     A new NFS file server has been referenced and is known to be down.

file server ${rhost} type nfs is up
     An NFS file server that was previously down is now up.

file server ${rhost} type nfs is down
     An NFS file server that was previously up is now down.

Finishing with status exit-status
     Amd is about to exit with the given exit status.

mount-info mounted fstype ${type} on ${fs}
     A new file system has been mounted.

mount-info restarted fstype ${type} on ${fs}
     Amd is using a pre-mounted filesystem to satisfy a mount request.

mount-info unmounted fstype ${type} from ${fs}
     A file system has been unmounted.

mount-info unmounted fstype ${type} from ${fs} link ${fs}/${sublink}
     A file system of which only a sub-directory was in use has been
     unmounted.


File: amdref.info,  Node: Acknowledgements & Trademarks,  Next: Index,  Prev: Internals,  Up: Top

Acknowledgements & Trademarks
*****************************

   Thanks to the Formal Methods Group at Imperial College for suffering
patiently while Amd was being developed on their machines.

   Thanks to the many people who have helped with the development of
Amd, especially Piete Brooks at the Cambridge University Computing Lab
for many hours of testing, experimentation and discussion.

   * DEC, VAX and Ultrix are registered trademarks of Digital Equipment
     Corporation.

   * AIX and IBM are registered trademarks of International Business
     Machines Corporation.

   * Sun, NFS and SunOS are registered trademarks of Sun Microsystems,
     Inc.

   * Unix is a registered trademark of AT&T Unix Systems Laboratories
     in the USA and other countries.


File: amdref.info,  Node: Index,  Next: Intro,  Prev: Acknowledgements & Trademarks,  Up: Top

Index
*****

* Menu:

* /etc/amd.start:                        Starting Amd.
* /etc/passwd maps:                      Password maps.
* /etc/rc.local additions:               Starting Amd.
* /vol:                                  /vol.
* Additions to /etc/rc.local:            Starting Amd.
* Aliased hostnames:                     -n Option.
* Alternate locations:                   Mounting a Volume.
* Amd command line options:              Amd Command Line Options.
* Amq command:                           Run-time Administration.
* arch, mount selector:                  Selectors.
* Architecture dependent volumes:        Architecture Sharing.
* Architecture sharing:                  Architecture Sharing.
* Architecture specific mounts:          rwho servers.
* Atomic NFS mounts:                     Network Filesystem Group.
* auto, filesystem type:                 Automount Filesystem.
* autodir, mount selector:               Selectors.
* Automatic generation of user maps:     Password maps.
* Automount directory:                   -a Option.
* Automount filesystem:                  Automount Filesystem.
* Automounter configuration maps:        Mount Maps.
* Automounter fundamentals:              Fundamentals.
* Background mounts:                     Mounting a Volume.
* Binding names to filesystems:          Volume Binding.
* Bug reports:                           Distrib.
* byte, mount selector:                  Selectors.
* Cache interval:                        -c Option.
* cache, mount option:                   Automount Filesystem.
* Catch-all mount point:                 /vol.
* Changing the interval before a filesystem times out: -c Option.
* Cluster names:                         -C-Option.
* cluster, mount selector:               Selectors.
* Command line options, Amd:             Amd Command Line Options.
* Configuration map types:               Map Types.
* Controlling Amd:                       Controlling Amd.
* Creating a pid file:                   -p Option.
* Debug options:                         -D-Option.
* delay, mount option:                   delay Option.
* Delaying mounts from specific locations: delay Option.
* Determining the map type:              Map Types.
* dev, mount option:                     Unix Filesystem.
* Direct automount filesystem:           Direct Automount Filesystem.
* direct, filesystem type:               Direct Automount Filesystem.
* Discovering version information:       -v Option.
* Discovering what is going on at run-time: Controlling Amd.
* Disk filesystems:                      Unix Filesystem.
* Displaying the process id:             -p Option.
* Domain name:                           -d Option.
* Domain stripping:                      Variable Expansion.
* domain, mount selector:                Selectors.
* Domainname operators:                  Variable Expansion.
* Duplicated volumes:                    Volume Naming.
* Environment variables:                 Variable Expansion.
* Error filesystem:                      Error Filesystem.
* error, filesystem type:                Error Filesystem.
* Example of architecture specific mounts: rwho servers.
* Example of mounting home directories:  Home Directories.
* File map syntactic conventions:        File maps.
* File maps:                             File maps.
* Fileserver:                            Filesystems and Volumes.
* Filesystem:                            Filesystems and Volumes.
* Filesystem type; auto:                 Automount Filesystem.
* Filesystem type; direct:               Direct Automount Filesystem.
* Filesystem type; error:                Error Filesystem.
* Filesystem type; host:                 Network Host Filesystem.
* Filesystem type; inherit:              Inheritance Filesystem.
* Filesystem type; link:                 Symbolic Link Filesystem.
* Filesystem type; linkx:                Symbolic Link Filesystem II.
* Filesystem type; nfs:                  Network Filesystem.
* Filesystem type; nfsx:                 Network Filesystem Group.
* Filesystem type; program:              Program Filesystem.
* Filesystem type; root:                 Root Filesystem.
* Filesystem type; toplvl:               Top-level Filesystem.
* Filesystem type; ufs:                  Unix Filesystem.
* Filesystem type; union:                Union Filesystem.
* Filesystem types:                      Filesystem Types.
* Flat file maps:                        File maps.
* Flushing the map cache:                Amq -f option.
* Forcing filesystem to time out:        Amq -u option.
* fs, mount option:                      fs Option.
* Generic volume name:                   /vol.
* Global statistics:                     Amq -s option.
* Hesiod maps:                           Hesiod maps.
* Home directories:                      Home Directories.
* host, filesystem type:                 Network Host Filesystem.
* host, mount selector:                  Selectors.
* hostd, mount selector:                 Selectors.
* Hostname normalisation:                -n Option.
* How keys are looked up:                Key Lookup.
* How locations are parsed:              Location Format.
* How to access environment variables in maps: Variable Expansion.
* How to discover your version of Amd:   -v Option.
* How to mount a local disk:             Unix Filesystem.
* How to mount a UFS filesystems:        Unix Filesystem.
* How to mount all NFS exported filesystems: Network Host Filesystem.
* How to mount an atomic group of NFS filesystems: Network Filesystem Group.
* How to mount and NFS filesystem:       Network Filesystem.
* How to reference an existing part of the local name space: Symbolic Link Filesystem II.
* How to reference part of the local name space: Symbolic Link Filesystem.
* How to select log messages:            -x Option.
* How to set default map parameters:     Map Defaults.
* How to set map cache parameters:       Automount Filesystem.
* How to start a direct automount point: Direct Automount Filesystem.
* How to start an indirect automount point: Automount Filesystem.
* How variables are expanded:            Variable Expansion.
* inherit, filesystem type:              Inheritance Filesystem.
* Inheritance filesystem:                Inheritance Filesystem.
* Interval before a filesystem times out: -c Option.
* Introduction:                          Intro.
* karch, mount selector:                 Selectors.
* Keep-alives:                           Keep-alives.
* Key lookup:                            Key Lookup.
* key, mount selector:                   Selectors.
* License Information:                   License.
* link, filesystem type:                 Symbolic Link Filesystem.
* linkx, filesystem type:                Symbolic Link Filesystem II.
* Listing currently mounted filesystems: Controlling Amd.
* Location format:                       Location Format.
* Location lists:                        Mounting a Volume.
* Log filename:                          -l Option.
* Log message selection:                 -x Option.
* Looking up keys:                       Key Lookup.
* Machine architecture names:            Supported Machine Architectures.
* Machine architectures supported by Amd: Supported Machine Architectures.
* Mailing list:                          Distrib.
* Map cache options:                     Automount Filesystem.
* Map cache synchronising:               Automount Filesystem.
* Map cache types:                       Automount Filesystem.
* Map cache, flushing:                   Amq -f option.
* Map defaults:                          Map Defaults.
* Map entry format:                      Location Format.
* Map lookup:                            Key Lookup.
* Map options:                           Map Options.
* Map types:                             Map Types.
* map, mount selector:                   Selectors.
* Mount a filesystem under program control: Program Filesystem.
* Mount home directories:                Home Directories.
* Mount information:                     Mount Maps.
* Mount map types:                       Map Types.
* Mount maps:                            Mount Maps.
* Mount option; cache:                   Automount Filesystem.
* Mount option; delay:                   delay Option.
* Mount option; dev:                     Unix Filesystem.
* Mount option; fs:                      fs Option.
* Mount option; mount:                   Program Filesystem.
* Mount option; opts:                    opts Option.
* Mount option; remopts:                 remopts Option.
* Mount option; rfs:                     Network Filesystem.
* Mount option; rhost:                   Network Filesystem.
* Mount option; sublink:                 sublink Option.
* Mount option; type:                    type Option.
* Mount option; unmount:                 Program Filesystem.
* Mount retries:                         Mounting a Volume.
* Mount selector; arch:                  Selectors.
* Mount selector; autodir:               Selectors.
* Mount selector; byte:                  Selectors.
* Mount selector; cluster:               Selectors.
* Mount selector; domain:                Selectors.
* Mount selector; host:                  Selectors.
* Mount selector; hostd:                 Selectors.
* Mount selector; karch:                 Selectors.
* Mount selector; key:                   Selectors.
* Mount selector; map:                   Selectors.
* Mount selector; os:                    Selectors.
* Mount selector; path:                  Selectors.
* Mount selector; wire:                  Selectors.
* mount system call:                     opts Option.
* mount system call flags:               opts Option.
* Mount types:                           Filesystem Types.
* mount, mount option:                   Program Filesystem.
* Mounting a local disk:                 Unix Filesystem.
* Mounting a UFS filesystem:             Unix Filesystem.
* Mounting a volume:                     Mounting a Volume.
* Mounting an atomic group of NFS filesystems: Network Filesystem Group.
* Mounting an existing part of the local name space: Symbolic Link Filesystem II.
* Mounting an NFS filesystem:            Network Filesystem.
* Mounting entire export trees:          Network Host Filesystem.
* Mounting part of the local name space: Symbolic Link Filesystem.
* Mounting user filesystems:             User Filesystems.
* Multiple-threaded server:              Non-blocking Operation.
* Namespace:                             Volume Binding.
* Network filesystem group:              Network Filesystem Group.
* Network host filesystem:               Network Host Filesystem.
* Network-wide naming:                   Volume Naming.
* NFS:                                   Network Filesystem.
* NFS ping:                              Keep-alives.
* nfs, filesystem type:                  Network Filesystem.
* nfsx, filesystem type:                 Network Filesystem Group.
* NIS (YP) domain name:                  -y Option.
* NIS (YP) maps:                         NIS maps.
* Nodes generated on a restart:          Inheritance Filesystem.
* Non-blocking operation:                Non-blocking Operation.
* Normalising hostnames:                 -n Option.
* Obtaining the source code:             Distrib.
* Operating system names:                Supported Operating Systems.
* Operating systems supported by Amd:    Supported Operating Systems.
* Operational principles:                Operational Principles.
* opts, mount option:                    opts Option.
* os, mount selector:                    Selectors.
* Overriding defaults on the command line: Amd Command Line Options.
* Overriding the default mount point:    fs Option.
* Overriding the local domain name:      -d Option.
* Overriding the NIS (YP) domain name:   -y Option.
* Passing parameters to the mount system call: opts Option.
* Password file maps:                    Password maps.
* path, mount selector:                  Selectors.
* Pathname operators:                    Variable Expansion.
* Picking up existing mounts:            -r Option.
* pid file, creating with -p option:     -p Option.
* Primary server:                        delay Option.
* Process id:                            -p Option.
* process id of Amd daemon:              -p Option.
* Program filesystem:                    Program Filesystem.
* program, filesystem type:              Program Filesystem.
* Querying an alternate host:            Amq -h option.
* Referencing an existing part of the local name space: Symbolic Link Filesystem II.
* Referencing part of the local name space: Symbolic Link Filesystem.
* Regular expressions in maps:           Automount Filesystem.
* remopts, mount option:                 remopts Option.
* Replacement volumes:                   Volume Naming.
* Replicated volumes:                    Volume Naming.
* Resolving aliased hostnames:           -n Option.
* Restarting existing mounts:            -r Option.
* rfs, mount option:                     Network Filesystem.
* rhost, mount option:                   Network Filesystem.
* Root filesystem:                       Root Filesystem.
* root, filesystem type:                 Root Filesystem.
* RPC retries:                           Non-blocking Operation.
* Run-time administration:               Run-time Administration.
* rwho servers:                          rwho servers.
* Secondary server:                      delay Option.
* Selecting specific log messages:       -x Option.
* Selector; arch:                        Selectors.
* Selector; autodir:                     Selectors.
* Selector; byte:                        Selectors.
* Selector; cluster:                     Selectors.
* Selector; domain:                      Selectors.
* Selector; host:                        Selectors.
* Selector; hostd:                       Selectors.
* Selector; karch:                       Selectors.
* Selector; key:                         Selectors.
* Selector; map:                         Selectors.
* Selector; os:                          Selectors.
* Selector; path:                        Selectors.
* Selector; wire:                        Selectors.
* Selectors:                             Selectors.
* Server crashes:                        Keep-alives.
* Setting a delay on a mount location:   delay Option.
* Setting Amd's RPC parameters:          -t Option.
* Setting debug flags:                   -D-Option.
* Setting default map parameters:        Map Defaults.
* Setting map cache parameters:          Automount Filesystem.
* Setting map options:                   Map Options.
* Setting system mount options:          opts Option.
* Setting system mount options for non-local networks: remopts Option.
* Setting the cluster name:              -C-Option.
* Setting the default mount directory:   -a Option.
* Setting the filesystem type option:    type Option.
* Setting the interval before a filesystem times out: -c Option.
* Setting the interval between unmount attempts: -w Option.
* Setting the Kernel architecture:       -k Option.
* Setting the local domain name:         -d Option.
* Setting the local mount point:         fs Option.
* Setting the log file:                  -l Option.
* Setting the NIS (YP) domain name:      -y Option.
* Setting the sublink option:            sublink Option.
* Sharing a fileserver between architectures: Architecture Sharing.
* SIGHUP signal:                         Automount Filesystem.
* SIGINT signal:                         Stopping Amd.
* SIGTERM signal:                        Stopping Amd.
* Source code distribution:              Distrib.
* Starting Amd:                          Starting Amd.
* Statistics:                            Amq -s option.
* Stopping Amd:                          Stopping Amd.
* Stripping the local domain name:       Variable Expansion.
* sublink:                               Filesystems and Volumes.
* sublink, mount option:                 sublink Option.
* Supported machine architectures:       Supported Machine Architectures.
* Supported operating systems:           Supported Operating Systems.
* Symbolic link filesystem:              Symbolic Link Filesystem.
* Symbolic link filesystem II:           Symbolic Link Filesystem II.
* symlink, link filesystem type:         Symbolic Link Filesystem.
* symlink, linkx filesystem type:        Symbolic Link Filesystem II.
* Synchronising the map cache:           Automount Filesystem.
* syslog:                                -l Option.
* syslog priorities:                     -x Option.
* The mount system call:                 opts Option.
* Top level filesystem:                  Top-level Filesystem.
* toplvl, filesystem type:               Top-level Filesystem.
* type, mount option:                    type Option.
* Types of configuration map:            Map Types.
* Types of filesystem:                   Filesystem Types.
* Types of mount map:                    Map Types.
* UFS:                                   Unix Filesystem.
* ufs, filesystem type:                  Unix Filesystem.
* Union file maps:                       Union maps.
* Union filesystem:                      Union Filesystem.
* union, filesystem type:                Union Filesystem.
* Unix filesystem:                       Unix Filesystem.
* Unix namespace:                        Volume Binding.
* unmount attempt backoff interval:      -w Option.
* unmount, mount option:                 Program Filesystem.
* Unmounting a filesystem:               Amq -u option.
* User filesystems:                      User Filesystems.
* User maps, automatic generation:       Password maps.
* Using syslog to log errors:            -l Option.
* Using the password file as a map:      Password maps.
* Variable expansion:                    Variable Expansion.
* Version information:                   -v Option.
* Version information at run-time:       Amq -v option.
* Volume:                                Filesystems and Volumes.
* Volume binding:                        Volume Binding.
* Volume names:                          Volume Naming.
* Wildcards in maps:                     Key Lookup.
* wire, mount selector:                  Selectors.
* YP domain name:                        -y Option.


