X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsystemd.timer.xml;h=55b458557f357634ae7f27591cbd8cddf7001e30;hp=5cc543e453ea42bfcf14af138beb2d09b31ff3c9;hb=9700d6980f7c212b10a69399e6430b82a6f45587;hpb=7a529f63e60dfdccc23d61808c20ba40d9901e47 diff --git a/man/systemd.timer.xml b/man/systemd.timer.xml index 5cc543e45..55b458557 100644 --- a/man/systemd.timer.xml +++ b/man/systemd.timer.xml @@ -48,14 +48,14 @@ - systemd.timer + timer.timer Description A unit configuration file whose name ends in - .timer encodes information about + .timer encodes information about a timer controlled and supervised by systemd, for timer-based activation. @@ -78,15 +78,20 @@ Unit= (see below). Unless DefaultDependencies= - is set to , timer units will + is set to , all timer units will implicitly have dependencies of type Conflicts= and Before= on - shutdown.target. These ensure - that timer units are stopped cleanly prior to system - shutdown. Only timer units involved with early boot or - late system shutdown should disable this - option. + shutdown.target to ensure that + they are stopped cleanly prior to system shutdown. + Timer units with at least one + OnCalendar= directive will have an + additional After= dependency on + timer-sync.target to avoid + being started before the system clock has been + correctly set. Only timer units involved with early + boot or late system shutdown should disable the + DefaultDependencies= option. @@ -97,7 +102,7 @@ defines. The options specific to the [Timer] section of timer units are the following: - + OnActiveSec= OnBootSec= @@ -115,7 +120,7 @@ machine was booted up. OnStartupSec= defines a timer relative to when - systemd was + systemd was first started. OnUnitActiveSec= defines a timer relative to when the unit the timer is activating was last @@ -128,7 +133,7 @@ combined of the same and of different types. For example, by combining OnBootSec= and - OnUnitActiveSec= it is + OnUnitActiveSec=, it is possible to define a timer that elapses in regular intervals and activates a specific service each @@ -141,7 +146,7 @@ also include time units. Example: "OnBootSec=5h 30min" means 5 hours and 30 minutes after boot-up. For details - about the syntax of time spans see + about the syntax of time spans, see systemd.unit5. If a timer configured with @@ -157,7 +162,20 @@ These are monotonic timers, independent of wall-clock time and timezones. If the computer is temporarily suspended, the - monotonic clock stops too. + monotonic clock stops too. + + If the empty string is assigned + to any of these options, the list of + timers is reset, and all prior + assignments will have no + effect. + + Note that timers do not + necessarily expire at the precise + time configured with these settings, + as they are subject to the + AccuracySec= + setting below. @@ -165,21 +183,68 @@ OnCalendar= Defines realtime - (i.e. wallclock) timers via calendar + (i.e. wallclock) timers with calendar event expressions. See systemd.time7 for more information on the syntax of - calendar event - expressions. + calendar event expressions. Otherwise, + the semantics are similar to + OnActiveSec= and + related settings. + + Note that timers do not + necessarily expire at the precise + time configured with this setting, + as it is subject to the + AccuracySec= + setting below. + + AccuracySec= + + Specify the accuracy + the timer shall elapse with. Defaults + to 1min. The timer is scheduled to + elapse within a time window starting + with the time specified in + OnCalendar=, + OnActiveSec=, + OnBootSec=, + OnStartupSec=, + OnUnitActiveSec= or + OnUnitInactiveSec= + and ending the time configured with + AccuracySec= + later. Within this time window, the + expiry time will be placed at a + host-specific, randomized but stable + position that is synchronized between + all local timer units. This is done in + order to distribute the wake-up time + in networked installations, as well as + optimizing power consumption to + suppress unnecessary CPU wake-ups. To + get best accuracy, set this option to + 1us. Note that the timer is still + subject to the timer slack configured + via + systemd-system.conf5's + TimerSlackNSec= + setting. See + prctl2 + for details. To optimize power + consumption, make sure to set this + value as high as possible and as low + as necessary. + Unit= The unit to activate when this timer elapses. The argument is a unit name, whose suffix is not - .timer. If not + .timer. If not specified, this value defaults to a service that has the same name as the timer unit, except for the @@ -189,6 +254,43 @@ are named identically, except for the suffix. + + + + Persistent= + + Takes a boolean + argument. If true, the time when the + service unit was last triggered is + stored on disk. When the timer is + activated, the service unit is + triggered immediately if it would have + been triggered at least once during + the time when the timer was inactive. + This is useful to catch up on missed + runs of the service when the machine + was off. Note that this setting only + has an effect on timers configured + with OnCalendar=. + + + + + WakeSystem= + + Takes a boolean + argument. If true, an elapsing timer + will cause the system to resume from + suspend, should it be suspended and if + the system supports this. Note that + this option will only make sure the + system resumes on the appropriate + times, it will not take care of + suspending it again after any work + that is to be done is + finished. Defaults to + false. + @@ -196,10 +298,13 @@ See Also systemd1, - systemctl8, + systemctl1, systemd.unit5, systemd.service5, - systemd.time7 + systemd.time7, + systemd.directives7, + systemd-system.conf5, + prctl2