systemd.special — Special systemd units
basic.target
,
bluetooth.target
,
ctrl-alt-del.target
,
cryptsetup.target
,
dbus.service
,
dbus.socket
,
default.target
,
display-manager.service
,
emergency.target
,
exit.service
,
final.service
,
getty.target
,
graphical.target
,
hibernate.target
,
http-daemon.target
,
halt.target
,
kbrequest.target
,
kexec.target
,
local-fs.target
,
local-fs-pre.target
,
mail-transfer-agent.target
,
multi-user.target
,
network.target
,
nss-lookup.target
,
nss-user-lookup.target
,
poweroff.target
,
printer.target
,
reboot.target
,
remote-fs.target
,
remote-fs-pre.target
,
rescue.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.service
,
syslog.socket
,
syslog.target
,
time-sync.target
,
umount.target
A few units are treated specially by systemd. They have special internal semantics and cannot be renamed.
basic.target
A special target unit covering early 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.
Usually this should pull-in all sockets, mount points, swap devices and other basic initialization necessary for the general purpose daemons. Most normal daemons should have dependencies of type After and Requires on this unit.
bluetooth.target
This target is started automatically as soon as a bluetooth controller is plugged in or becomes available at boot.
ctrl-alt-del.target
systemd starts this
target whenever
Control+Alt+Del is pressed on
the console. Usually this
should be aliased (symlinked)
to
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 system bus. 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
The default unit systemd
starts at bootup. Usually this
should be aliased (symlinked)
to
multi-user.target
or
graphical.target
.
The default unit systemd
starts at bootup can be
overridden with the
systemd.unit=
kernel command line option.
display-manager.service
The display manager
service. Usually this should
be aliased (symlinked) to
gdm.service
or a similar display manager
service.
systemd automatically
adds dependencies of type
After for this target unit to
all SysV init script service
units with a LSB header
referring to the
$x-display-manager
facility, for compatibility
with Debian.
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.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 all local TTY
getty
instances.
graphical.target
A special target unit
for setting up a graphical
login screen. This pulls in
multi-user.target
.
Units that are needed
for graphical login shall add
Wants dependencies for their
unit to this unit (or
multi-user.target
)
during installation.
hibernate.target
A special target unit
for hibernating the
system. This pulls in
sleep.target
.
http-daemon.target
A target for pulling in an HTTP server if there is any.
systemd automatically
adds dependencies of type
After for this target unit to
all SysV init script service
units with a LSB header
referring to the
$httpd
facility.
halt.target
A special target unit for shutting down and halting the system.
Applications wanting to halt the system should start this unit.
kbrequest.target
systemd starts this
target whenever Alt+ArrowUp is
pressed on the console. This
is a good candidate to be
aliased (symlinked) to
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
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
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.
local-fs-pre.target
This target unit is
automatically ordered before
all local mount points marked
with auto
(see above). It can be used to
execute certain units before
all local mounts.
mail-transfer-agent.target
The mail transfer agent (MTA) service. Usually this should pull-in all units necessary for sending/receiving mails on the local host.
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
$mail-transfer-agent
or
$mail-transport-agent
facilities, for compatibility
with Debian.
multi-user.target
A special target unit
for setting up a multi-user
system (non-graphical). This
is pulled in by
graphical.target
.
Units that are needed for a multi-user system shall add Wants dependencies to this unit for their unit during installation.
network.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.
nss-lookup.target
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.
nss-user-lookup.target
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.
poweroff.target
A special target unit for shutting down and powering off the system.
Applications wanting to power off the system should start this unit.
runlevel0.target
is an alias for this target
unit, for compatibility with SysV.
printer.target
This target is started automatically as soon as a printer is plugged in or becomes available at boot.
reboot.target
A special target unit for shutting down and rebooting the system.
Applications wanting to reboot the system should start this unit.
runlevel6.target
is an alias for this target
unit, for compatibility with SysV.
remote-fs.target
Similar to
local-fs.target
,
but for remote mount
points.
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
facility.
remote-fs-pre.target
This target unit is
automatically ordered before
all remote mount points marked
with auto
(see above). It can be used to
execute certain units before
all remote mounts.
rescue.target
A special target unit for setting up the base system and a rescue shell.
runlevel1.target
is an alias for this target
unit, for compatibility with SysV.
rpcbind.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.
runlevel2.target
This is a target that is
called whenever 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
.
runlevel3.target
This is a target that is
called whenever 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
.
runlevel4.target
This is a target that is
called whenever 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
.
runlevel5.target
This is a target that is
called whenever 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
.
shutdown.target
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).
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.
sigpwr.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.
sleep.target
A special target unit
that is pulled in by
suspend.target
and
hibernate.target
and may be used to hook units
into the sleep state
logic.
smartcard.target
This target is started automatically as soon as a smartcard controller is plugged in or becomes available at boot.
sockets.target
A special target unit that sets up all service sockets.
Services that can be socket-activated shall add Wants dependencies to this unit for their socket unit during installation.
sound.target
This target is started automatically as soon as a sound card is plugged in or becomes available at boot.
suspend.target
A special target unit
for suspending the
system. This pulls in
sleep.target
.
swap.target
Similar to
local-fs.target
, but for swap
partitions and swap
files.
sysinit.target
A special target unit covering early boot-up scripts.
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.
syslog.service
The syslog service if any. Implementations should create a symlink from the actual syslog implementation to this generic name for activating it.
syslog.socket
The socket unit where syslog implementations should listen on. All userspace log messages will be made available on this socket.
syslog.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
$syslog
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.
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 mount unit, which is
implicitly done when
DefaultDependencies=yes
is set (the default).
When systemd runs as a user instance, the
following special units are available, which have
similar definitions as their system counterparts:
default.target
,
shutdown.target
,
sockets.target
In addition the following special unit is understood only when systemd runs as service instance:
exit.service
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.