1SYSTEMD.SPECIAL(7) systemd.special SYSTEMD.SPECIAL(7)
2
6 systemd.special - Special systemd units
7
9 basic.target, bluetooth.target, cryptsetup-pre.target,
10 cryptsetup.target, ctrl-alt-del.target, blockdev@.target,
11 boot-complete.target, default.target, emergency.target, exit.target,
12 final.target, getty.target, getty-pre.target, graphical.target,
13 halt.target, hibernate.target, hybrid-sleep.target,
14 suspend-then-hibernate.target, initrd.target, initrd-fs.target,
15 initrd-root-device.target, initrd-root-fs.target, kbrequest.target,
16 kexec.target, local-fs-pre.target, local-fs.target, machines.target
17 multi-user.target, network-online.target, network-pre.target,
18 network.target, nss-lookup.target, nss-user-lookup.target,
19 paths.target, poweroff.target, printer.target, reboot.target,
20 remote-cryptsetup.target, remote-fs-pre.target, remote-fs.target,
21 rescue.target, rpcbind.target, runlevel2.target, runlevel3.target,
22 runlevel4.target, runlevel5.target, shutdown.target, sigpwr.target,
23 sleep.target, slices.target, smartcard.target, sockets.target,
24 sound.target, suspend.target, swap.target, sysinit.target,
25 system-update.target, system-update-pre.target, time-set.target,
26 time-sync.target, timers.target, umount.target, usb-gadget.target,
27 -.slice, system.slice, user.slice, machine.slice, -.mount,
28 dbus.service, dbus.socket, display-manager.service, init.scope,
29 syslog.socket, system-update-cleanup.service
30
32 A few units are treated specially by systemd. Many of them have special
33 internal semantics and cannot be renamed, while others simply have a
34 standard meaning and should be present on all systems.
35
37 Special System Units
38 -.mount
39 The root mount point, i.e. the mount unit for the / path. This unit
40 is unconditionally active, during the entire time the system is up,
41 as this mount point is where the basic userspace is running from.
42 basic.target
44 A special target unit covering basic boot-up.
45 systemd automatically adds dependency of the type After= for this
47 target unit to all services (except for those with
48 DefaultDependencies=no).
49 Usually, this should pull-in all local mount points plus /var, /tmp
51 and /var/tmp, swap devices, sockets, timers, path units and other
52 basic initialization necessary for general purpose daemons. The
53 mentioned mount points are special cased to allow them to be
54 remote.
55 This target usually does not pull in any non-target units directly,
57 but rather does so indirectly via other early boot targets. It is
58 instead meant as a synchronization point for late boot services.
59 Refer to bootup(7) for details on the targets involved.
60 boot-complete.target
62 This target is intended as generic synchronization point for
63 services that shall determine or act on whether the boot process
64 completed successfully. Order units that are required to succeed
65 for a boot process to be considered successful before this unit,
66 and add a Requires= dependency from the target unit to them. Order
67 units that shall only run when the boot process is considered
68 successful after the target unit and pull in the target from it,
69 also with Requires=. Note that by default this target unit is not
70 part of the initial boot transaction, but is supposed to be pulled
71 in only if required by units that want to run only on successful
72 boots.
73 See systemd-boot-check-no-failures.service(8) for a service that
75 implements a generic system health check and orders itself before
76 boot-complete.target.
77 See systemd-bless-boot.service(8) for a service that propagates
79 boot success information to the boot loader, and orders itself
80 after boot-complete.target.
81 ctrl-alt-del.target
83 systemd starts this target whenever Control+Alt+Del is pressed on
84 the console. Usually, this should be aliased (symlinked) to
85 reboot.target.
86 cryptsetup.target
88 A target that pulls in setup services for all encrypted block
89 devices.
90 dbus.service
92 A special unit for the D-Bus bus daemon. As soon as this service is
93 fully started up systemd will connect to it and register its
94 service.
95 dbus.socket
97 A special unit for the D-Bus system bus socket. All units with
98 Type=dbus automatically gain a dependency on this unit.
99 default.target
101 The default unit systemd starts at bootup. Usually, this should be
102 aliased (symlinked) to multi-user.target or graphical.target. See
103 bootup(7) for more discussion.
104 The default unit systemd starts at bootup can be overridden with
106 the systemd.unit= kernel command line option, or more conveniently,
107 with the short names like single, rescue, 1, 3, 5, ...; see
108 systemd(1).
109 display-manager.service
111 The display manager service. Usually, this should be aliased
112 (symlinked) to gdm.service or a similar display manager service.
113 emergency.target
115 A special target unit that starts an emergency shell on the main
116 console. This target does not pull in other services or mounts. It
117 is the most minimal version of starting the system in order to
118 acquire an interactive shell; the only processes running are
119 usually just the system manager (PID 1) and the shell process. This
120 unit may be used by specifying emergency on the kernel command
121 line; it is also used when a file system check on a required file
122 system fails and boot-up cannot continue. Compare with
123 rescue.target, which serves a similar purpose, but also starts the
124 most basic services and mounts all file systems.
125 In many ways booting into emergency.target is similar to the effect
127 of booting with "init=/bin/sh" on the kernel command line, except
128 that emergency mode provides you with the full system and service
129 manager, and allows starting individual units in order to continue
130 the boot process in steps.
131 Note that depending on how emergency.target is reached, the root
133 file system might be mounted read-only or read-write (no remounting
134 is done specially for this target). For example, the system may
135 boot with root mounted read-only when ro is used on the kernel
136 command line and remain this way for emergency.target, or the
137 system may transition to emergency.target after the system has been
138 partially booted and disks have already been remounted read-write.
139 exit.target
141 A special service unit for shutting down the system or user service
142 manager. It is equivalent to poweroff.target on non-container
143 systems, and also works in containers.
144 systemd will start this unit when it receives the SIGTERM or SIGINT
146 signal when running as user service daemon.
147 Normally, this (indirectly) pulls in shutdown.target, which in turn
149 should be conflicted by all units that want to be scheduled for
150 shutdown when the service manager starts to exit.
151 final.target
153 A special target unit that is used during the shutdown logic and
154 may be used to pull in late services after all normal services are
155 already terminated and all mounts unmounted.
156 getty.target
158 A special target unit that pulls in statically configured local TTY
159 getty instances.
160 graphical.target
162 A special target unit for setting up a graphical login screen. This
163 pulls in multi-user.target.
164 Units that are needed for graphical logins shall add Wants=
166 dependencies for their unit to this unit (or multi-user.target)
167 during installation. This is best configured via
168 WantedBy=graphical.target in the unit's [Install] section.
169 hibernate.target
171 A special target unit for hibernating the system. This pulls in
172 sleep.target.
173 hybrid-sleep.target
175 A special target unit for hibernating and suspending the system at
176 the same time. This pulls in sleep.target.
177 suspend-then-hibernate.target
179 A special target unit for suspending the system for a period of
180 time, waking it and putting it into hibernate. This pulls in
181 sleep.target.
182 halt.target
184 A special target unit for shutting down and halting the system.
185 Note that this target is distinct from poweroff.target in that it
186 generally really just halts the system rather than powering it
187 down.
188 Applications wanting to halt the system should not start this unit
190 directly, but should instead execute systemctl halt (possibly with
191 the --no-block option) or call systemd(1)'s
192 org.freedesktop.systemd1.Manager.Halt D-Bus method directly.
193 init.scope
195 This scope unit is where the system and service manager (PID 1)
196 itself resides. It is active as long as the system is running.
197 initrd.target
199 This is the default target in the initramfs, similar to
200 default.target in the main system. It is used to mount the real
201 root and transition to it. See bootup(7) for more discussion.
202 initrd-fs.target
204 systemd-fstab-generator(3) automatically adds dependencies of type
205 Before= to sysroot-usr.mount and all mount points found in
206 /etc/fstab that have x-initrd.mount and not have noauto mount
207 options set.
208 initrd-root-device.target
210 A special initrd target unit that is reached when the root
211 filesystem device is available, but before it has been mounted.
212 systemd-fstab-generator(3) and systemd-gpt-auto-generator(3)
213 automatically setup the appropriate dependencies to make this
214 happen.
215 initrd-root-fs.target
217 systemd-fstab-generator(3) automatically adds dependencies of type
218 Before= to the sysroot.mount unit, which is generated from the
219 kernel command line.
220 kbrequest.target
222 systemd starts this target whenever Alt+ArrowUp is pressed on the
223 console. Note that any user with physical access to the machine
224 will be able to do this, without authentication, so this should be
225 used carefully.
226 kexec.target
228 A special target unit for shutting down and rebooting the system
229 via kexec.
230 Applications wanting to reboot the system should not start this
232 unit directly, but should instead execute systemctl kexec (possibly
233 with the --no-block option) or call systemd(1)'s
234 org.freedesktop.systemd1.Manager.KExec D-Bus method directly.
235 local-fs.target
237 systemd-fstab-generator(3) automatically adds dependencies of type
238 Before= to all mount units that refer to local mount points for
239 this target unit. In addition, it adds dependencies of type Wants=
240 to this target unit for those mounts listed in /etc/fstab that have
241 the auto mount option set.
242 machines.target
244 A standard target unit for starting all the containers and other
245 virtual machines. See systemd-nspawn@.service for an example.
246 multi-user.target
248 A special target unit for setting up a multi-user system
249 (non-graphical). This is pulled in by graphical.target.
250 Units that are needed for a multi-user system shall add Wants=
252 dependencies for their unit to this unit during installation. This
253 is best configured via WantedBy=multi-user.target in the unit's
254 [Install] section.
255 network-online.target
257 Units that strictly require a configured network connection should
258 pull in network-online.target (via a Wants= type dependency) and
259 order themselves after it. This target unit is intended to pull in
260 a service that delays further execution until the network is
261 sufficiently set up. What precisely this requires is left to the
262 implementation of the network managing service.
263 Note the distinction between this unit and network.target. This
265 unit is an active unit (i.e. pulled in by the consumer rather than
266 the provider of this functionality) and pulls in a service which
267 possibly adds substantial delays to further execution. In contrast,
268 network.target is a passive unit (i.e. pulled in by the provider of
269 the functionality, rather than the consumer) that usually does not
270 delay execution much. Usually, network.target is part of the boot
271 of most systems, while network-online.target is not, except when at
272 least one unit requires it. Also see Running Services After the
273 Network is up[1] for more information.
274 All mount units for remote network file systems automatically pull
276 in this unit, and order themselves after it. Note that networking
277 daemons that simply provide functionality to other hosts generally
278 do not need to pull this in.
279 systemd automatically adds dependencies of type Wants= and After=
281 for this target unit to all SysV init script service units with an
282 LSB header referring to the "$network" facility.
283 Note that this unit is only useful during the original system
285 start-up logic. After the system has completed booting up, it will
286 not track the online state of the system anymore. Due to this it
287 cannot be used as a network connection monitor concept, it is
288 purely a one-time system start-up concept.
289 paths.target
291 A special target unit that sets up all path units (see
292 systemd.path(5) for details) that shall be active after boot.
293 It is recommended that path units installed by applications get
295 pulled in via Wants= dependencies from this unit. This is best
296 configured via a WantedBy=paths.target in the path unit's [Install]
297 section.
298 poweroff.target
300 A special target unit for shutting down and powering off the
301 system.
302 Applications wanting to power off the system should not start this
304 unit directly, but should instead execute systemctl poweroff
305 (possibly with the --no-block option) or call systemd-logind(8)'s
306 org.freedesktop.login1.Manager.PowerOff D-Bus method directly.
307 runlevel0.target is an alias for this target unit, for
309 compatibility with SysV.
310 reboot.target
312 A special target unit for shutting down and rebooting the system.
313 Applications wanting to reboot the system should not start this
315 unit directly, but should instead execute systemctl reboot
316 (possibly with the --no-block option) or call systemd-logind(8)'s
317 org.freedesktop.login1.Manager.Reboot D-Bus method directly.
318 runlevel6.target is an alias for this target unit, for
320 compatibility with SysV.
321 remote-cryptsetup.target
323 Similar to cryptsetup.target, but for encrypted devices which are
324 accessed over the network. It is used for crypttab(8) entries
325 marked with _netdev.
326 remote-fs.target
328 Similar to local-fs.target, but for remote mount points.
329 systemd automatically adds dependencies of type After= for this
331 target unit to all SysV init script service units with an LSB
332 header referring to the "$remote_fs" facility.
333 rescue.target
335 A special target unit that pulls in the base system (including
336 system mounts) and spawns a rescue shell. Isolate to this target in
337 order to administer the system in single-user mode with all file
338 systems mounted but with no services running, except for the most
339 basic. Compare with emergency.target, which is much more reduced
340 and does not provide the file systems or most basic services.
341 Compare with multi-user.target, this target could be seen as
342 single-user.target.
343 runlevel1.target is an alias for this target unit, for
345 compatibility with SysV.
346 Use the "systemd.unit=rescue.target" kernel command line option to
348 boot into this mode. A short alias for this kernel command line
349 option is "1", for compatibility with SysV.
350 runlevel2.target, runlevel3.target, runlevel4.target, runlevel5.target
352 These are targets that are called whenever the SysV compatibility
353 code asks for runlevel 2, 3, 4, 5, respectively. It is a good idea
354 to make this an alias for (i.e. symlink to) graphical.target (for
355 runlevel 5) or multi-user.target (the others).
356 shutdown.target
358 A special target unit that terminates the services on system
359 shutdown.
360 Services that shall be terminated on system shutdown shall add
362 Conflicts= and Before= dependencies to this unit for their service
363 unit, which is implicitly done when DefaultDependencies=yes is set
364 (the default).
365 sigpwr.target
367 A special target that is started when systemd receives the SIGPWR
368 process signal, which is normally sent by the kernel or UPS daemons
369 when power fails.
370 sleep.target
372 A special target unit that is pulled in by suspend.target,
373 hibernate.target and hybrid-sleep.target and may be used to hook
374 units into the sleep state logic.
375 slices.target
377 A special target unit that sets up all slice units (see
378 systemd.slice(5) for details) that shall always be active after
379 boot. By default the generic system.slice slice unit as well as the
380 root slice unit -.slice are pulled in and ordered before this unit
381 (see below).
382 Adding slice units to slices.target is generally not necessary.
384 Instead, when some unit that uses Slice= is started, the specified
385 slice will be started automatically. Adding WantedBy=slices.target
386 lines to the [Install] section should only be done for units that
387 need to be always active. In that case care needs to be taken to
388 avoid creating a loop through the automatic dependencies on
389 "parent" slices.
390 sockets.target
392 A special target unit that sets up all socket units (see
393 systemd.socket(5) for details) that shall be active after boot.
394 Services that can be socket-activated shall add Wants= dependencies
396 to this unit for their socket unit during installation. This is
397 best configured via a WantedBy=sockets.target in the socket unit's
398 [Install] section.
399 suspend.target
401 A special target unit for suspending the system. This pulls in
402 sleep.target.
403 swap.target
405 Similar to local-fs.target, but for swap partitions and swap files.
406 sysinit.target
408 systemd automatically adds dependencies of the types Requires= and
409 After= for this target unit to all services (except for those with
410 DefaultDependencies=no).
411 This target pulls in the services required for system
413 initialization. System services pulled in by this target should
414 declare DefaultDependencies=no and specify all their dependencies
415 manually, including access to anything more than a read only root
416 filesystem. For details on the dependencies of this target, refer
417 to bootup(7).
418 syslog.socket
420 The socket unit syslog implementations should listen on. All
421 userspace log messages will be made available on this socket. For
422 more information about syslog integration, please consult the
423 Syslog Interface[2] document.
424 system-update.target, system-update-pre.target,
426 system-update-cleanup.service
427 A special target unit that is used for offline system updates.
428 systemd-system-update-generator(8) will redirect the boot process
429 to this target if /system-update exists. For more information see
430 systemd.offline-updates(7).
431 Updates should happen before the system-update.target is reached,
433 and the services which implement them should cause the machine to
434 reboot. The main units executing the update should order themselves
435 after system-update-pre.target but not pull it in. Services which
436 want to run during system updates only, but before the actual
437 system update is executed should order themselves before this unit
438 and pull it in. As a safety measure, if this does not happen, and
439 /system-update still exists after system-update.target is reached,
440 system-update-cleanup.service will remove this symlink and reboot
441 the machine.
442 timers.target
444 A special target unit that sets up all timer units (see
445 systemd.timer(5) for details) that shall be active after boot.
446 It is recommended that timer units installed by applications get
448 pulled in via Wants= dependencies from this unit. This is best
449 configured via WantedBy=timers.target in the timer unit's [Install]
450 section.
451 umount.target
453 A special target unit that unmounts all mount and automount points
454 on system shutdown.
455 Mounts that shall be unmounted on system shutdown shall add
457 Conflicts dependencies to this unit for their mount unit, which is
458 implicitly done when DefaultDependencies=yes is set (the default).
459 Special System Units for Devices
461 Some target units are automatically pulled in as devices of certain
462 kinds show up in the system. These may be used to automatically
463 activate various services based on the specific type of the available
464 hardware.
465 bluetooth.target
467 This target is started automatically as soon as a Bluetooth
468 controller is plugged in or becomes available at boot.
469 This may be used to pull in Bluetooth management daemons
471 dynamically when Bluetooth hardware is found.
472 printer.target
474 This target is started automatically as soon as a printer is
475 plugged in or becomes available at boot.
476 This may be used to pull in printer management daemons dynamically
478 when printer hardware is found.
479 smartcard.target
481 This target is started automatically as soon as a smartcard
482 controller is plugged in or becomes available at boot.
483 This may be used to pull in smartcard management daemons
485 dynamically when smartcard hardware is found.
486 sound.target
488 This target is started automatically as soon as a sound card is
489 plugged in or becomes available at boot.
490 This may be used to pull in audio management daemons dynamically
492 when audio hardware is found.
493 usb-gadget.target
495 This target is started automatically as soon as a USB Device
496 Controller becomes available at boot.
497 This may be used to pull in usb gadget dynamically when UDC
499 hardware is found.
500 Special Passive System Units
502 A number of special system targets are defined that can be used to
503 properly order boot-up of optional services. These targets are
504 generally not part of the initial boot transaction, unless they are
505 explicitly pulled in by one of the implementing services. Note
506 specifically that these passive target units are generally not pulled
507 in by the consumer of a service, but by the provider of the service.
508 This means: a consuming service should order itself after these targets
509 (as appropriate), but not pull it in. A providing service should order
510 itself before these targets (as appropriate) and pull it in (via a
511 Wants= type dependency).
512 Note that these passive units cannot be started manually, i.e.
514 "systemctl start time-sync.target" will fail with an error. They can
515 only be pulled in by dependency. This is enforced since they exist for
516 ordering purposes only and thus are not useful as only unit within a
517 transaction.
518 blockdev@.target
520 This template unit is used to order mount units and other consumers
521 of block devices after services that synthesize these block
522 devices. In particular, this is intended to be used with storage
523 services (such as systemd-cryptsetup@.service(5)) that allocate and
524 manage a virtual block device. Storage services are ordered before
525 an instance of blockdev@.target, and the consumer units after it.
526 The ordering is particularly relevant during shutdown, as it
527 ensures that the mount is deactivated first and the service backing
528 the mount later. The blockdev@.target instance should be pulled in
529 via a Wants= dependency of the storage daemon and thus generally
530 not be part of any transaction unless a storage daemon is used. The
531 instance name for instances of this template unit must be a
532 properly escaped block device node path, e.g.
533 blockdev@dev-mapper-foobar.target for the storage device
534 /dev/mapper/foobar.
535 cryptsetup-pre.target
537 This passive target unit may be pulled in by services that want to
538 run before any encrypted block device is set up. All encrypted
539 block devices are set up after this target has been reached. Since
540 the shutdown order is implicitly the reverse start-up order between
541 units, this target is particularly useful to ensure that a service
542 is shut down only after all encrypted block devices are fully
543 stopped.
544 getty-pre.target
546 A special passive target unit. Users of this target are expected to
547 pull it in the boot transaction via a dependency (e.g. Wants=).
548 Order your unit before this unit if you want to make use of the
549 console just before getty is started.
550 local-fs-pre.target
552 This target unit is automatically ordered before all local mount
553 points marked with auto (see above). It can be used to execute
554 certain units before all local mounts.
555 network.target
557 This unit is supposed to indicate when network functionality is
558 available, but it is only very weakly defined what that is supposed
559 to mean, with one exception: at shutdown, a unit that is ordered
560 after network.target will be stopped before the network — to
561 whatever level it might be set up then — is shut down. It is hence
562 useful when writing service files that require network access on
563 shutdown, which should order themselves after this target, but not
564 pull it in. Also see Running Services After the Network is up[1]
565 for more information. Also see network-online.target described
566 above.
567 network-pre.target
569 This passive target unit may be pulled in by services that want to
570 run before any network is set up, for example for the purpose of
571 setting up a firewall. All network management software orders
572 itself after this target, but does not pull it in.
573 nss-lookup.target
575 A target that should be used as synchronization point for all
576 host/network name service lookups. Note that this is independent of
577 UNIX user/group name lookups for which nss-user-lookup.target
578 should be used. All services for which the availability of full
579 host/network name resolution is essential should be ordered after
580 this target, but not pull it in. systemd automatically adds
581 dependencies of type After= for this target unit to all SysV init
582 script service units with an LSB header referring to the "$named"
583 facility.
584 nss-user-lookup.target
586 A target that should be used as synchronization point for all
587 regular UNIX user/group name service lookups. Note that this is
588 independent of host/network name lookups for which
589 nss-lookup.target should be used. All services for which the
590 availability of the full user/group database is essential should be
591 ordered after this target, but not pull it in. All services which
592 provide parts of the user/group database should be ordered before
593 this target, and pull it in. Note that this unit is only relevant
594 for regular users and groups — system users and groups are required
595 to be resolvable during earliest boot already, and hence do not
596 need any special ordering against this target.
597 remote-fs-pre.target
599 This target unit is automatically ordered before all mount point
600 units (see above) and cryptsetup devices marked with the _netdev.
601 It can be used to run certain units before remote encrypted devices
602 and mounts are established. Note that this unit is generally not
603 part of the initial transaction, unless the unit that wants to be
604 ordered before all remote mounts pulls it in via a Wants= type
605 dependency. If the unit wants to be pulled in by the first remote
606 mount showing up, it should use network-online.target (see above).
607 rpcbind.target
609 The portmapper/rpcbind pulls in this target and orders itself
610 before it, to indicate its availability. systemd automatically adds
611 dependencies of type After= for this target unit to all SysV init
612 script service units with an LSB header referring to the "$portmap"
613 facility.
614 time-set.target
616 Services responsible for setting the system clock from a local
617 source (such as a maintained timestamp file or imprecise real-time
618 clock) should pull in this target and order themselves before it.
619 Services where approximate time is desired should be ordered after
620 this unit, but not pull it in. This target does not provide the
621 accuracy guarantees of time-sync.target.
622 time-sync.target
624 Services responsible for synchronizing the system clock from a
625 remote source (such as NTP client implementations) should pull in
626 this target and order themselves before it. All services where
627 correct time is essential should be ordered after this unit, but
628 not pull it in. systemd automatically adds dependencies of type
629 After= for this target unit to all SysV init script service units
630 with an LSB header referring to the "$time" facility.
631 Special Slice Units
633 There are four ".slice" units which form the basis of the hierarchy for
634 assignment of resources for services, users, and virtual machines or
635 containers. See systemd.slice(7) for details about slice units.
636 -.slice
638 The root slice is the root of the slice hierarchy. It usually does
639 not contain units directly, but may be used to set defaults for the
640 whole tree.
641 system.slice
643 By default, all system services started by systemd are found in
644 this slice.
645 user.slice
647 By default, all user processes and services started on behalf of
648 the user, including the per-user systemd instance are found in this
649 slice. This is pulled in by systemd-logind.service.
650 machine.slice
652 By default, all virtual machines and containers registered with
653 systemd-machined are found in this slice. This is pulled in by
654 systemd-machined.service.
655
657 Special User Units
658 When systemd runs as a user instance, the following special units are
659 available:
660 default.target
662 This is the main target of the user session, started by default.
663 Various services that compose the normal user session should be
664 pulled into this target. In this regard, default.target is similar
665 to multi-user.target in the system instance, but it is a real unit,
666 not an alias.
667 In addition, the following units are available which have definitions
669 similar to their system counterparts: exit.target, shutdown.target,
670 sockets.target, timers.target, paths.target, bluetooth.target,
671 printer.target, smartcard.target, sound.target.
672 Special Passive User Units
674 graphical-session.target
675 This target is active whenever any graphical session is running. It
676 is used to stop user services which only apply to a graphical (X,
677 Wayland, etc.) session when the session is terminated. Such
678 services should have "PartOf=graphical-session.target" in their
679 [Unit] section. A target for a particular session (e. g.
680 gnome-session.target) starts and stops "graphical-session.target"
681 with "BindsTo=graphical-session.target".
682 Which services are started by a session target is determined by the
684 "Wants=" and "Requires=" dependencies. For services that can be
685 enabled independently, symlinks in ".wants/" and ".requires/"
686 should be used, see systemd.unit(5). Those symlinks should either
687 be shipped in packages, or should be added dynamically after
688 installation, for example using "systemctl add-wants", see
689 systemctl(1).
690 Example 1. Nautilus as part of a GNOME session
692 "gnome-session.target" pulls in Nautilus as top-level service:
693 [Unit]
695 Description=User systemd services for GNOME graphical session
696 Wants=nautilus.service
697 BindsTo=graphical-session.target
698 "nautilus.service" gets stopped when the session stops:
700 [Unit]
702 Description=Render the desktop icons with Nautilus
703 PartOf=graphical-session.target
704 [Service]
706 ...
707 graphical-session-pre.target
709 This target contains services which set up the environment or
710 global configuration of a graphical session, such as SSH/GPG agents
711 (which need to export an environment variable into all desktop
712 processes) or migration of obsolete d-conf keys after an OS upgrade
713 (which needs to happen before starting any process that might use
714 them). This target must be started before starting a graphical
715 session like gnome-session.target.
716 xdg-desktop-autostart.target
718 The XDG specification defines a way to autostart applications using
719 XDG desktop files. systemd ships systemd-xdg-autostart-generator(8)
720 for the XDG desktop files in autostart directories. Desktop
721 Environments can opt-in to use this service by adding a Wants=
722 dependency on "xdg-desktop-autostart.target" .
723 .RE
724
726 systemd(1), systemd.unit(5), systemd.service(5), systemd.socket(5),
727 systemd.target(5), systemd.slice(5), bootup(7), systemd-fstab-
728 generator(8), user@.service(5)
729
731 1. Running Services After the Network is up
732 https://www.freedesktop.org/wiki/Software/systemd/NetworkTarget
733 2. Syslog Interface
735 https://www.freedesktop.org/wiki/Software/systemd/syslog
736systemd 246 SYSTEMD.SPECIAL(7)