1SYSTEMD.SPECIAL(7) systemd.special SYSTEMD.SPECIAL(7)
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6 systemd.special - special systemd units
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9 basic.target, ctrl-alt-del.target, dbus.service, dbus.target,
10 default.target, display-manager.service, emergency.target,
11 exit.service, graphical.target, halt.target, kbrequest.target,
12 local-fs.target, mail-transfer-agent.target, multi-user.target,
13 network.target, nss-lookup.target, poweroff.target, reboot.target,
14 remote-fs.target, rescue.target, rpcbind.target, rtc-set.target,
15 runlevel2.target, runlevel3.target, runlevel4.target, runlevel5.target,
16 shutdown.target, sigpwr.target, sockets.target, swap.target,
17 sysinit.target, rsyslog.service, syslog.target,
18 systemd-initctl.service, systemd-initctl.socket,
19 systemd-logger.service, systemd-logger.socket, umount.target
20
22 A few units are treated specially by systemd. They have special
23 internal semantics and cannot be renamed.
24
26 basic.target
27 A special target unit covering early boot-up.
28 systemd automatically adds dependencies of the types Requires and
30 After for this target unit to all SysV service units configured for
31 runlevel 1 to 5.
32 Usually this should pull-in all sockets, mount points, swap devices
34 and other basic initialization necessary for the general purpose
35 daemons. Most normal daemons should have dependencies of type After
36 and Requires on this unit.
37 ctrl-alt-del.target
39 systemd starts this target whenever Control+Alt+Del is pressed on
40 the console. Usually this should be aliased (symlinked) to
41 reboot.target.
42 dbus.service
44 A special unit for the D-Bus system bus. As soon as this service is
45 fully started up systemd will connect to it and register its
46 service.
47 Units should generally avoid depending on this unit directly and
49 instead refer to the dbus.target unit instead, which pulls this one
50 in directly or indirectly via socket-based activation.
51 dbus.target
53 Administrators should ensure that this target pulls in a service
54 unit with the name or alias of dbus.service (or a socket unit that
55 activates this service).
56 default.target
58 The default unit systemd starts at bootup. Usually this should be
59 aliased (symlinked) to multi-user.target or graphical.target.
60 The default unit systemd starts at bootup can be overriden with the
62 systemd.default= kernel command line option.
63 display-manager.service
65 The display manager service. Usually this should be aliased
66 (symlinked) to xdm.service or a similar display manager service.
67 systemd automatically adds dependencies of type After for this
69 target unit to all SysV init script service units with a LSB header
70 referring to the $x-display-manager facility, for compatibility
71 with Debian.
72 emergency.target
74 A special target unit that starts an emergency shell on the main
75 console. This unit is supposed to be used with the kernel command
76 line option systemd.default= and has otherwise little use.
77 graphical.target
79 A special target unit for setting up a graphical login screen. This
80 pulls in multi-user.target.
81 Units that are needed for graphical login shall add Wants
83 dependencies for their unit to this unit (or multi-user.target)
84 during installation.
85 halt.target
87 A special target unit for shutting down and halting the system.
88 Applications wanting to halt the system should start this unit.
90 kbrequest.target
92 systemd starts this target whenever Alt+ArrowUp is pressed on the
93 console. This is a good candidate to be aliased (symlinked) to
94 rescue.target.
95 local-fs.target
97 systemd automatically adds dependencies of type After to all mount
98 units that refer to local mount points for this target unit. In
99 addition, systemd adds dependencies of type Wants to this target
100 unit for those mounts listed in /etc/fstab that have the auto and
101 comment=systemd.mount mount options set.
102 systemd automatically adds dependencies of type After for this
104 target unit to all SysV init script service units with an LSB
105 header referring to the $local_fs facility.
106 mail-transfer-agent.target
108 The mail transfer agent (MTA) service. Usually this should pull-in
109 all units necessary for sending/receiving mails on the local host.
110 systemd automatically adds dependencies of type After for this
112 target unit to all SysV init script service units with an LSB
113 header referring to the $mail-transfer-argent or
114 $mail-transport-agent facilities, for compatibility with Debian.
115 multi-user.target
117 A special target unit for setting up a multi-user system
118 (non-graphical). This is pulled in by graphical.target.
119 Units that are needed for a multi-user system shall add Wants
121 dependencies to this unit for their unit during installation.
122 network.target
124 systemd automatically adds dependencies of type After for this
125 target unit to all SysV init script service units with an LSB
126 header referring to the $network facility.
127 nss-lookup.target
129 systemd automatically adds dependencies of type After for this
130 target unit to all SysV init script service units with an LSB
131 header referring to the $named facility.
132 poweroff.target
134 A special target unit for shutting down and powering off the
135 system.
136 Applications wanting to power off the system should start this
138 unit.
139 runlevel0.target is an alias for this target unit, for
141 compatibility with SysV.
142 reboot.target
144 A special target unit for shutting down and rebooting the system.
145 Applications wanting to reboot the system should start this unit.
147 runlevel6.target is an alias for this target unit, for
149 compatibility with SysV.
150 remote-fs.target
152 Similar to local-fs.target, but for remote mount points.
153 systemd automatically adds dependencies of type After for this
155 target unit to all SysV init script service units with an LSB
156 header referring to the $remote_fs facility.
157 rescue.target
159 A special target unit for setting up the base system and a rescue
160 shell.
161 runlevel1.target is an alias for this target unit, for
163 compatibility with SysV.
164 rpcbind.target
166 systemd automatically adds dependencies of type After for this
167 target unit to all SysV init script service units with an LSB
168 header referring to the $rpcbind facility.
169 rtc-set.target
171 systemd automatically adds dependencies of type After for this
172 target unit to all SysV init script service units with an LSB
173 header referring to the $time facility.
174 runlevel2.target
176 This is a target that is called whever the SysV compatibility code
177 asks for runlevel 2. It is a good idea to make this an alias for
178 (i.e. symlink to) multi-user.target.
179 runlevel3.target
181 This is a target that is called whever the SysV compatibility code
182 asks for runlevel 3. It is a good idea to make this an alias for
183 (i.e. symlink to) multi-user.target or graphical.target.
184 runlevel4.target
186 This is a target that is called whever the SysV compatibility code
187 asks for runlevel 4. It is a good idea to make this an alias for
188 (i.e. symlink to) multi-user.target or graphical.target.
189 runlevel5.target
191 This is a target that is called whever the SysV compatibility code
192 asks for runlevel 5. It is a good idea to make this an alias for
193 (i.e. symlink to) multi-user.target or graphical.target.
194 shutdown.target
196 A special target unit that terminates the services on system
197 shutdown.
198 Services that shall be terminated on system shutdown shall add
200 Conflicts dependencies to this unit for their service unit, which
201 is implicitly done when DefaultDependencies=yes is set (the
202 default).
203 systemd automatically adds dependencies of type Conflicts to this
205 target unit for all SysV init script service units that shall be
206 terminated in SysV runlevels 0 or 6.
207 sigpwr.target
209 A special target that is started when systemd receives the SIGPWR
210 process signal, which is normally sent by the kernel or UPS daemons
211 when power fails.
212 sockets.target
214 A special target unit that sets up all service sockets.
215 Services that can be socket-activated shall add Wants dependencies
217 to this unit for their socket unit during installation.
218 swap.target
220 Similar to local-fs.target, but for swap partitions and swap files.
221 sysinit.target
223 A special target unit covering early boot-up scripts.
224 systemd automatically adds dependencies of the types Wants and
226 After for all SysV service units configured for runlevels that are
227 not 0 to 6 to this target unit. This covers the special boot-up
228 runlevels some distributions have, such as S or b.
229 rsyslog.service
231 A special unit for the syslog daemon. As soon as this service is
232 fully started up systemd will connect to it and use it for logging
233 if it has been configured for that.
234 Units should generally avoid depending on this unit directly and
236 instead refer to the syslog.target unit instead, which pulls this
237 one in directly or indirectly via socket-based activation.
238 syslog.target
240 systemd automatically adds dependencies of type After for this
241 target unit to all SysV init script service units with an LSB
242 header referring to the $syslog facility.
243 Administrators should ensure that this target pulls in a service
245 unit with the name or alias of rsyslog.service (or a socket unit
246 that activates this service).
247 systemd-initctl.service
249 This provides compatibility with the SysV /dev/initctl file system
250 FIFO for communication with the init system.
251 This is a socket-activated service, see system-initctl.socket.
253 systemd-initctl.socket
255 Socket activation unit for system-initctl.service.
256 systemd-logger.service
258 This is internally used by systemd to provide syslog logging to the
259 processes it maintains.
260 This is a socket-activated service, see system-logger.socket.
262 systemd-logger.socket
264 Socket activation unit for system-logger.service. systemd will
265 automatically add dependencies of types Requires and After to all
266 units that have been configured for stdout or stderr to be
267 connected to syslog or the kernel log buffer.
268 systemd-shutdownd.service
270 This is internally used by shutdown(8) to implement delayed
271 shutdowns.
272 This is a socket-activated service, see system-shutdownd.socket.
274 systemd-shutdownd.socket
276 Socket activation unit for system-shutdownd.service.
277 umount.target
279 A special target unit that umounts all mount and automount points
280 on system shutdown.
281 Mounts that shall be unmounted on system shutdown shall add
283 Conflicts dependencies to this unit for their mount unit, which is
284 implicitly done when DefaultDependencies=yes is set (the default).
285
287 When systemd runs as a service instance, the following special units
288 are available, which have similar definitions as their system
289 counterparts: default.target, local-fs.target, remote-fs.target,
290 shutdown.target, sockets.target, swap.target.
291 In addition the following special unit is understood only when systemd
293 runs as service instance:
294 exit.service
296 A special service unit for shutting down the session.
297 Applications wanting to terminate the session should start this
299 unit. If systemd receives SIGTERM or SIGINT when running as session
300 daemon it will start this unit.
301 Normally, this pulls in shutdown.target which in turn should be
303 conflicted by all units that want to be shut down on session exit.
304
306 systemd.unit(5), systemd.service(5), systemd.socket(5),
307 systemd.target(5)
308
310 Lennart Poettering <lennart@poettering.net>
311 Developer
312systemd 09/14/2010 SYSTEMD.SPECIAL(7)