1SYSTEMD.TIMER(5) systemd.timer SYSTEMD.TIMER(5)
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6 systemd.timer - systemd timer configuration files
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9 systemd.timer
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12 A unit configuration file whose name ends in .timer encodes information
13 about a timer controlled and supervised by systemd, for timer-based
14 activation.
15 This man page lists the configuration options specific to this unit
17 type. See systemd.unit(5) for the common options of all unit
18 configuration files. The common configuration items are configured in
19 the generic [Unit] and [Install] sections. The timer specific
20 configuration options are configured in the [Timer] section.
21 For each timer file, a matching unit file must exist, describing the
23 unit to activate when the timer elapses. By default, a service by the
24 same name as the timer (except for the suffix) is activated. Example: a
25 timer file foo.timer activates a matching service foo.service. The unit
26 to activate may be controlled by Unit= (see below).
27 Unless DefaultDependencies= is set to false, timer units will
29 implicitly have dependencies of type Conflicts= and Before= on
30 shutdown.target. These ensure that timer units are stopped cleanly
31 prior to system shutdown. Only timer units involved with early boot or
32 late system shutdown should disable this option.
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35 Timer files must include a [Timer] section, which carries information
36 about the timer it defines. The options specific to the [Timer] section
37 of timer units are the following:
38 OnActiveSec=, OnBootSec=, OnStartupSec=, OnUnitActiveSec=,
40 OnUnitInactiveSec=
41 Defines timers relative to different starting points: OnActiveSec=
42 defines a timer relative to the moment the timer itself is
43 activated. OnBootSec= defines a timer relative to when the machine
44 was booted up. OnStartupSec= defines a timer relative to when
45 systemd was started. OnUnitActiveSec= defines a timer relative to
46 when the unit the timer is activating was last activated.
47 OnUnitInactiveSec= defines a timer relative to when the unit the
48 timer is activating was last deactivated.
49 Multiple directives may be combined of the same and of different
51 types. For example, by combining OnBootSec= and OnUnitActiveSec= it
52 is possible to define a timer that elapses in regular intervals and
53 activates a specific service each time.
54 The arguments to the directives are time spans configured in
56 seconds. Example: "OnBootSec=50" means 50s after boot-up. The
57 argument may also include time units. Example: "OnBootSec=5h 30min"
58 means 5 hours and 30 minutes after boot-up. For details about the
59 syntax of time spans see systemd.unit(5).
60 If a timer configured with OnBootSec= or OnStartupSec= is already
62 in the past when the timer unit is activated, it will immediately
63 elapse and the configured unit is started. This is not the case for
64 timers defined in the other directives.
65 These are monotonic timers, independent of wall-clock time and
67 timezones. If the computer is temporarily suspended, the monotonic
68 clock stops too.
69 Unit=
71 The unit to activate when this timer elapses. The argument is a
72 unit name, whose suffix is not .timer. If not specified, this value
73 defaults to a service that has the same name as the timer unit,
74 except for the suffix. (See above.) It is recommended that the unit
75 name that is activated and the unit name of the timer unit are
76 named identically, except for the suffix.
77
79 systemd(1), systemctl(8), systemd.unit(5), systemd.service(5)
80
82 Lennart Poettering <lennart@poettering.net>
83 Developer
84systemd 09/14/2010 SYSTEMD.TIMER(5)