X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsystemd.special.xml;h=8ccccc2798713a4b0f6a7d1d9fdee0781d320ce0;hp=e81e99e44efe07ce4572ae6c9c8d1abec34d3e37;hb=d86dd07d462fb8502b1c7b4a9a4df4fba8318bdd;hpb=bd3d19a4ea3b007bea4c94213cafd5dc37ce7a3d
diff --git a/man/systemd.special.xml b/man/systemd.special.xml
index e81e99e44..8ccccc279 100644
--- a/man/systemd.special.xml
+++ b/man/systemd.special.xml
@@ -8,16 +8,16 @@
Copyright 2010 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- General Public License for more details.
+ Lesser General Public License for more details.
- You should have received a copy of the GNU General Public License
+ You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see .
-->
@@ -44,42 +44,67 @@
systemd.special
- special systemd units
+ Special systemd units
- basic.target
- ctrl-alt-del.target
- default.target
- emergency.service
- graphical.target
- halt.target
- kbrequest.target
- local-fs.target
- multi-user.target
- network.target
- nss-lookup.target
- poweroff.target
- reboot.target
- remote-fs.target
- rescue.target
- rpcbind.target
- rtc-set.target
- runlevel0.target,
- runlevel0.target,
- runlevel1.target,
- runlevel2.target,
- runlevel3.target,
- runlevel4.target,
- runlevel5.target,
- runlevel6.target
- shutdown.target
- sigpwr.target
- sockets.target
- swap.target
- syslog.target
- systemd-initctl.service, systemd-initctl.socket
- systemd-logger.service, systemd-logger.socket
+ basic.target,
+ bluetooth.target,
+ ctrl-alt-del.target,
+ cryptsetup.target,
+ dbus.service,
+ dbus.socket,
+ default.target,
+ display-manager.service,
+ emergency.target,
+ exit.target,
+ final.target,
+ getty.target,
+ graphical.target,
+ halt.target,
+ hibernate.target,
+ hybrid-sleep.target,
+ initrd-fs.target,
+ kbrequest.target,
+ kexec.target,
+ local-fs.target,
+ local-fs-pre.target,
+ multi-user.target,
+ network.target,
+ network-online.target,
+ nss-lookup.target,
+ nss-user-lookup.target,
+ paths.target,
+ poweroff.target,
+ printer.target,
+ reboot.target,
+ remote-fs.target,
+ remote-fs-pre.target,
+ rescue.target,
+ initrd-root-fs.target,
+ rpcbind.target,
+ runlevel2.target,
+ runlevel3.target,
+ runlevel4.target,
+ runlevel5.target,
+ shutdown.target,
+ sigpwr.target,
+ sleep.target,
+ smartcard.target,
+ sockets.target,
+ sound.target,
+ suspend.target,
+ swap.target,
+ sysinit.target,
+ syslog.socket,
+ system-update.target,
+ time-sync.target,
+ timers.target,
+ umount.target,
+ -.slice,
+ system.slice,
+ user.slice,
+ machine.slice
@@ -98,23 +123,23 @@
basic.targetA special target unit
- covering early boot-up.
+ covering basic boot-up.
systemd automatically
adds dependencies of the types
- Requires and After for this
- target unit to all SysV
- service units configured for
- runlevel 1 to 5.
- systemd automatically
- adds dependencies of the types
- Wants and After for all
- SysV service units configured
- for runlevels that are not 0
- to 6 to this target unit.
- This covers the special
- boot-up runlevels some
- distributions have, such as S
- or b.
+ Requires=
+ and After=
+ for this target unit to all
+ services (except for those
+ with
+ DefaultDependencies=no).
+
+ Usually this should
+ pull-in all mount points, swap
+ devices, sockets, timers, and
+ path units and other basic
+ initialization necessary for
+ general purpose
+ daemons.
@@ -129,6 +154,38 @@
reboot.target.
+
+ cryptsetup.target
+
+ A target that pulls in
+ setup services for all
+ encrypted block
+ devices.
+
+
+
+ dbus.service
+
+ A special unit for the
+ D-Bus bus daemon. As soon as
+ this service is fully started
+ up systemd will connect to it
+ and register its
+ service.
+
+
+
+ dbus.socket
+
+ A special unit for the
+ D-Bus system bus socket. All
+ units with
+ Type=dbus
+ automatically gain a
+ dependency on this
+ unit.
+
+ default.target
@@ -139,27 +196,63 @@
multi-user.target
or
graphical.target.
+
The default unit systemd
starts at bootup can be
- overriden with the
- systemd.default=
+ overridden with the
+ systemd.unit=
kernel command line option.
- emergency.service
+ display-manager.service
- A special service unit
+ The display manager
+ service. Usually this should
+ be aliased (symlinked) to
+ gdm.service
+ or a similar display manager
+ service.
+
+
+
+ emergency.target
+
+ A special target unit
that starts an emergency
shell on the main
console. This unit is supposed
to be used with the kernel
command line option
- systemd.default=
+ systemd.unit=
and has otherwise little use.
+
+ final.target
+
+ A special target unit
+ that is used during the
+ shutdown logic and may be used
+ to pull in late services after
+ all normal services are
+ already terminated and all
+ mounts unmounted.
+
+
+
+
+ getty.target
+
+ A special target unit
+ that pulls in statically
+ configured local TTY
+ getty
+ instances.
+
+
+ graphical.target
@@ -169,24 +262,71 @@
multi-user.target.
Units that are needed
- for graphical login shall add
- Wants dependencies for their
- unit to this unit (or
+ for graphical logins shall add
+ Wants=
+ dependencies for their unit to
+ this unit (or
multi-user.target)
- during installation.
+ during installation. This is
+ best configured via
+ WantedBy=graphical.target
+ in the unit's
+ [Install]
+ section.
+
+
+
+ hibernate.target
+
+ A special target unit
+ for hibernating the
+ system. This pulls in
+ sleep.target.
+
+
+
+ hybrid-sleep.target
+
+ A special target unit
+ for hibernating and suspending the
+ system at the same time. This pulls in
+ sleep.target.halt.targetA special target unit
- for shutting down and halting the system.
+ for shutting down and halting
+ the system. Note that this
+ target is distinct from
+ poweroff.target
+ in that it generally really
+ just halts the system rather
+ than powering it down.
Applications wanting to
halt the system should start
this unit.
+
+ initrd-fs.target
+
+ systemd-fstab-generator3
+ automatically adds
+ dependencies of type
+ Before= to
+ sysroot-usr.mount
+ and all mount points found in
+ /etc/fstab
+ that have the
+ and
+
+ mount options set.
+
+
+ kbrequest.target
@@ -198,32 +338,35 @@
rescue.target.
+
+ kexec.target
+
+ A special target unit
+ for shutting down and rebooting the system via kexec.
+
+ Applications wanting to
+ reboot the system with kexec should start
+ this unit.
+
+ local-fs.target
- systemd automatically
+ systemd-fstab-generator3
+ automatically adds
+ dependencies of type
+ Before= to
+ all mount units that refer to
+ local mount points for this
+ target unit. In addition, it
adds dependencies of type
- After to all mount units that
- refer to local mount points
- for this target unit. In
- addition, systemd adds
- dependencies of type Wants to
+ Wants= to
this target unit for those
mounts listed in
/etc/fstab
that have the
- auto and
- comment=systemd.mount
- mount options set.
-
- systemd automatically
- adds dependencies of type
- After for this target unit to
- all SysV init script service
- units with an LSB header
- referring to the
- $local_fs
- facility.
+ mount
+ option set.
@@ -237,35 +380,99 @@
Units that are needed
for a multi-user system shall
- add Wants dependencies to
- this unit for their unit during
- installation.
+ add Wants=
+ dependencies for their unit to
+ this unit during
+ installation. This is best
+ configured via
+ WantedBy=multi-user.target
+ in the unit's
+ [Install]
+ section.
- network.target
+ network-online.target
- systemd automatically
- adds dependencies of type
- After for this target unit to
- all SysV init script service
- units with an LSB header
- referring to the
- $network
- facility.
-
+ Units that strictly
+ require a configured network
+ connection should pull in
+ network-online.target
+ (via a
+ Wants= type
+ dependency) and order
+ themselves after it. This
+ target unit is intended to
+ pull in a service that delays
+ further execution until the
+ network is sufficiently set
+ up. What precisely this
+ requires is left to the
+ implementation of the network
+ managing service.
+
+ Note the distinction
+ between this unit and
+ network.target. This
+ unit is an active unit
+ (i.e. pulled in by the
+ consumer rather than the
+ provider of this
+ functionality) and pulls in a
+ service which possibly adds
+ substantial delays to further
+ execution. In contrast,
+ network.target
+ is a passive unit (i.e. pulled
+ in by the provider of the
+ functionality, rather than the
+ consumer) that usually does
+ not delay execution
+ much. Usually,
+ network.target
+ is part of the boot of most
+ systems, while
+ network-online.target
+ is not, except when at least
+ one unit requires it. Also see
+ Running
+ Services After the Network is
+ up for more
+ information.
+
+ All mount units for
+ remote network file systems
+ automatically pull in this
+ unit, and order themselves
+ after it. Note that networking
+ daemons that simply provide
+ functionality to other hosts
+ generally do not need to pull
+ this in.
+
- nss-lookup.target
+ paths.target
- systemd automatically
- adds dependencies of type
- After for this target unit to
- all SysV init script service
- units with an LSB header
- referring to the
- $named
- facility.
+ A special target unit
+ that sets up all path units
+ (see
+ systemd.path5
+ for details) that shall be
+ active after boot.
+
+ It is recommended that
+ path units installed by
+ applications get pulled in via
+ Wants=
+ dependencies from this
+ unit. This is best configured
+ via a
+ WantedBy=paths.target
+ in the path unit's
+ [Install]
+ section.
@@ -308,11 +515,11 @@
systemd automatically
adds dependencies of type
- After for this target unit to
- all SysV init script service
- units with an LSB header
- referring to the
- $remote-fs
+ After= for
+ this target unit to all SysV
+ init script service units with
+ an LSB header referring to the
+ $remote_fs
facility.
@@ -329,275 +536,564 @@
- rpcbind.target
+ initrd-root-fs.target
- systemd automatically
- adds dependencies of type
- After for this target unit to
- all SysV init script service
- units with an LSB header
- referring to the
- $rpcbind
- facility.
+ systemd-fstab-generator3
+ automatically adds
+ dependencies of type
+ Before= to
+ the
+ sysroot.mount
+ unit, which is generated from
+ the kernel command line.
+
- rtc-set.target
+ runlevel2.target
+ runlevel3.target
+ runlevel4.target
+ runlevel5.target
- systemd automatically
- adds dependencies of type
- After for this target unit to
- all SysV init script service
- units with an LSB header
- referring to the
- $time
- facility.
+ These are targets that
+ are called whenever the SysV
+ compatibility code asks for
+ runlevel 2, 3, 4, 5,
+ respectively. It is a good
+ idea to make this an alias for
+ (i.e. symlink to)
+ multi-user.target
+ (for runlevel 2) or
+ graphical.target
+ (the others).
- runlevel0.target
+ shutdown.target
- This is a target that is
- called whever the SysV
- compatibility code asks for
- runlevel 0. This is an alias
- for
- poweroff.target,
- for compatibility with
- SysV.
+ A special target unit
+ that terminates the services
+ on system shutdown.
+
+ Services that shall be
+ terminated on system shutdown
+ shall add Conflicts=
+ dependencies to this unit for
+ their service unit, which is
+ implicitly done when
+ DefaultDependencies=yes
+ is set (the default).
- runlevel1.target
+ sigpwr.target
- This is a target that is
- called whever the SysV
- compatibility code asks for
- runlevel 1. This is an alias
- for
- rescue.target,
- for compatibility with
- SysV.
+ A special target that is
+ started when systemd receives
+ the SIGPWR process signal,
+ which is normally sent by the
+ kernel or UPS daemons when
+ power fails.
- runlevel2.target
+ sleep.target
- This is a target that is
- called whever the SysV
- compatibility code asks for
- runlevel 2. It is a good idea
- to make this an alias for
- (i.e. symlink to)
- multi-user.target.
+ A special target unit
+ that is pulled in by
+ suspend.target,
+ hibernate.target
+ and
+ hybrid-sleep.target
+ and may be used to hook units
+ into the sleep state
+ logic.
- runlevel3.target
+ sockets.target
- This is a target that is
- called whever the SysV
- compatibility code asks for
- runlevel 3. It is a good idea
- to make this an alias for
- (i.e. symlink to)
- multi-user.target
- or
- graphical.target.
+ A special target unit
+ that sets up all socket
+ units.(see
+ systemd.socket5
+ for details) that shall be
+ active after boot.
+
+ Services that can be
+ socket-activated shall add
+ Wants=
+ dependencies to this unit for
+ their socket unit during
+ installation. This is best
+ configured via a
+ WantedBy=sockets.target
+ in the socket unit's
+ [Install]
+ section.
- runlevel4.target
+ suspend.target
- This is a target that is
- called whever the SysV
- compatibility code asks for
- runlevel 4. It is a good idea
- to make this an alias for
- (i.e. symlink to)
- multi-user.target
- or
- graphical.target.
+ A special target unit
+ for suspending the
+ system. This pulls in
+ sleep.target.
- runlevel5.target
+ swap.target
- This is a target that is
- called whever the SysV
- compatibility code asks for
- runlevel 5. It is a good idea
- to make this an alias for
- (i.e. symlink to)
- multi-user.target
- or
- graphical.target.
+ Similar to
+ local-fs.target, but for swap
+ partitions and swap
+ files.
- runlevel6.target
+ sysinit.target
- This is a target that is
- called whever the SysV
- compatibility code asks for
- runlevel 6. This is an alias
- for
- reboot.target,
- for compatibility with
- SysV.
+ A special target unit
+ covering early boot-up scripts.
- shutdown.target
+ syslog.socket
+
+ The socket unit
+ syslog implementations should
+ listen on. All userspace log
+ messages will be made
+ available on this socket. For
+ more information about syslog
+ integration, please consult
+ the Syslog
+ Interface
+ document.
+
+
+
+ system-update.targetA special target unit
- that terminates the services
- on system shutdown.
+ that is used for off-line
+ system updates.
+ systemd-system-update-generator8
+ will redirect the boot process
+ to this target if
+ /system-update
+ exists. For more information
+ see the System
+ Updates
+ Specification.
+
+
+
+ timers.target
+
+ A special target unit
+ that sets up all timer
+ units (see
+ systemd.timer5
+ for details) that shall be
+ active after boot.
- Services that shall be
- terminated on system shutdown
+ It is recommended that
+ timer units installed by
+ applications get pulled in via
+ Wants=
+ dependencies from this
+ unit. This is best configured
+ via
+ WantedBy=timers.target
+ in the timer unit's
+ [Install]
+ section.
+
+
+
+ umount.target
+
+ A special target unit
+ that umounts all mount and
+ automount points on system
+ shutdown.
+
+ Mounts that shall be
+ unmounted on system shutdown
shall add Conflicts
dependencies to this unit for
- their service unit during
- installation.
+ their mount unit, which is
+ implicitly done when
+ DefaultDependencies=yes
+ is set (the default).
+
+
- systemd automatically
- adds dependencies of type
- Conflicts to this target unit
- for all SysV init script
- service units that shall be
- terminated in SysV runlevels 0
- or 6.
+
+
+
+
+ Special System Units for Devices
+
+ Some target units are automatically pulled in as
+ devices of certain kinds show up in the system. These
+ may be used to automatically activate various services
+ based on the specific type of the available
+ hardware.
+
+
+
+ bluetooth.target
+
+ This target is started
+ automatically as soon as a
+ Bluetooth controller is
+ plugged in or becomes
+ available at boot.
+
+ This may be used to pull
+ in Bluetooth management
+ daemons dynamically when
+ Bluetooth hardware is
+ found.
- sigpwr.target
+ printer.target
- A special target that is
- started when systemd receives
- the SIGPWR process signal,
- which is normally sent by the
- kernel or UPS daemons when
- power fails.
+ This target is started
+ automatically as soon as a
+ printer is plugged in or
+ becomes available at
+ boot.
+
+ This may be used to pull
+ in printer management
+ daemons dynamically when
+ printer hardware is
+ found.
- sockets.target
+ smartcard.target
- A special target unit
- that sets up all service
- sockets.
+ This target is started
+ automatically as soon as a
+ smartcard controller is
+ plugged in or becomes
+ available at boot.
- Services that can be
- socket-activated shall add
- Wants dependencies to this
- unit for their socket unit
- during installation.
+ This may be used to pull
+ in smartcard management
+ daemons dynamically when
+ smartcard hardware is
+ found.
- swap.target
+ sound.target
- Similar to
- local-fs.target, but for swap
- partitions and swap
- files.
+ This target is started
+ automatically as soon as a
+ sound card is plugged in or
+ becomes available at
+ boot.
+
+ This may be used to pull
+ in audio management daemons
+ dynamically when audio
+ hardware is found.
+
+
+
+
+
+
+ Special Passive System Units
+
+ A number of special system targets are defined
+ that can be used to properly order boot-up of optional
+ services. These targets are generally not part of the
+ initial boot transaction, unless they are explicitly
+ pulled in by one of the implementing services. Note
+ specifically that these passive
+ target units are generally not pulled in by the
+ consumer of a service, but by the provider of the
+ service. This means: a consuming service should order
+ itself after these targets (as appropriate), but not
+ pull it in. A providing service should order itself
+ before these targets (as appropriate) and pull it in
+ (via a Wants= type
+ dependency).
+
+ Note that these passive units cannot be started
+ manually, i.e. systemctl start
+ time-sync.target will fail with an
+ error. They can only be pulled in by dependency. This
+ is enforced since they exist for ordering purposes
+ only and thus are not useful as only unit within a
+ transaction.
+
+
+
+ local-fs-pre.target
+
+ This target unit is
+ automatically ordered before
+ all local mount points marked
+ with
+ (see above). It can be used to
+ execute certain units before
+ all local mounts.
- syslog.target
+ network.target
+ This unit is supposed to
+ indicate when network
+ functionality is available,
+ but it is only very weakly
+ defined what that is supposed
+ to mean, with one exception:
+ at shutdown, a unit that is
+ ordered after
+ network.target
+ will be stopped before the
+ network -- to whatever level
+ it might be set up then -- is
+ shut down. Also see Running
+ Services After the Network is
+ up for more
+ information. Also see
+ network-online.target
+ described above.
+
systemd automatically
adds dependencies of type
- After for this target unit to
- all SysV init script service
- units with an LSB header
- referring to the
- $syslog
+ After= for
+ this target unit to all SysV
+ init script service units with
+ an LSB header referring to the
+ $network
facility.
- Administrators should
- ensure that this target pulls
- in a service unit with the
- name or alias of
- @SPECIAL_SYSLOG_SERVICE@
- (or a socket unit that
- activates this
- service).
- systemd-initctl.service
+ nss-lookup.target
- This provides
- compatibility with the SysV
- /dev/initctl file system FIFO
- for communication with the
- init system.
- This is a
- socket-activated service, see
- system-initctl.socket.
+ A target that should be
+ used as synchronization point
+ for all host/network name
+ service lookups. Note that
+ this is independent of
+ user/group name lookups for
+ which
+ nss-user-lookup.target
+ should be used. systemd
+ automatically adds
+ dependencies of type
+ After= for
+ this target unit to all SysV
+ init script service units with
+ an LSB header referring to the
+ $named
+ facility.
- systemd-initctl.socket
+ nss-user-lookup.target
- Socket activation unit
- for
- system-initctl.service.
+ A target that should be
+ used as synchronization point
+ for all user/group name
+ service lookups. Note that
+ this is independent of
+ host/network name lookups for
+ which
+ nss-lookup.target
+ should be used.
- systemd-logger.service
+ remote-fs-pre.target
- This is internally used
- by systemd to provide syslog
- logging to the processes it
- maintains.
- This is a
- socket-activated service, see
- system-logger.socket.
+ This target unit is
+ automatically ordered before
+ all remote mount point units
+ (see above). It can be used to
+ run certain units before the
+ remote mounts are
+ established. Note that this
+ unit is generally not part of
+ the initial transaction,
+ unless the unit that wants to
+ be ordered before all remote
+ mounts pulls it in via a
+ Wants= type
+ dependency. If the unit wants
+ to be pulled in by the first
+ remote mount showing up, it
+ should use
+ network-online.target
+ (see above).
+
+ Again, this target unit
+ is not
+ suitable for pulling in other
+ units, it is only useful for
+ ordering.
- systemd-logger.socket
+ rpcbind.target
- Socket activation unit
- for
- system-logger.service. systemd
- will automatically add
- dependencies of types Requires
- and After to all units that
- have been configured for
- stdout or stderr to be
- connected to syslog or the
- kernel log buffer.
+ systemd automatically
+ adds dependencies of type
+ After= for
+ this target unit to all SysV
+ init script service units with
+ an LSB header referring to the
+ $portmap
+ facility.
+
+
+
+ time-sync.target
+
+ systemd automatically
+ adds dependencies of type
+ After= for
+ this target unit to all SysV
+ init script service units with
+ an LSB header referring to the
+ $time
+ facility.
- Special Session Units
+ Special User Units
- When systemd runs as a service instance, the
+ When systemd runs as a user instance, the
following special units are available, which have
similar definitions as their system counterparts:
default.target,
- local-fs.target,
- remote-fs.target,
shutdown.target,
sockets.target,
- swap.target.
+ timers.target,
+ paths.target,
+ bluetooth.target,
+ printer.target,
+ smartcard.target,
+ sound.target.
+
+ In addition, the following special unit is
+ understood only when systemd runs as service instance:
+
+
+
+ exit.target
+
+ A special service unit
+ for shutting down the
+ user service manager.
+
+ Applications wanting to
+ terminate the user service
+ manager should start this
+ unit. If systemd receives
+ SIGTERM or SIGINT when running
+ as user service daemon, it will
+ start this unit.
+
+ Normally, this pulls in
+ shutdown.target
+ which in turn should be
+ conflicted by all units that
+ want to be shut down on
+ user service manager exit.
+
+
+
+
+
+
+ Special Slice Units
+
+ There are four .slice units
+ which form the basis of the hierarchy for assignment
+ of resources for services, users, and virtual machines
+ or containers.
+
+
+
+ -.slice
+
+ The root slice is the
+ root of the hierarchy. It
+ usually does not contain units
+ directly, but may be used to
+ set defaults for the whole
+ tree.
+
+
+
+
+ system.slice
+
+ By default, all services
+ services started by
+ systemd are
+ found in this slice.
+
+
+
+
+ user.slice
+
+ By default, all user
+ processes and services started
+ on behalf of the user,
+ including the per-user systemd
+ instance are found in this
+ slice.
+
+
+
+
+ machine.slice
+
+ By defalt, all virtual
+ machines and containers
+ registered with
+ systemd-machined
+ are found in this slice.
+
+
+
+ See Also
- systemd.unit5
- systemd.service5
- systemd.socket5
- systemd.target5
+ systemd1,
+ systemd.unit5,
+ systemd.service5,
+ systemd.socket5,
+ systemd.target5,
+ systemd.slice5,
+ bootup7,
+ systemd-fstab-generator8