X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsystemd.timer.xml;h=b60199c2f7fb696ca4607fdec8e40b35d3125096;hp=868264334923c40aa410e8666b7085363d88071a;hb=06642d1795382a4849aa750ee54238f91e2f3126;hpb=74051b9b5865586bf4d30b9075649af838fb92bd diff --git a/man/systemd.timer.xml b/man/systemd.timer.xml index 868264334..b60199c2f 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. @@ -97,7 +97,7 @@ defines. The options specific to the [Timer] section of timer units are the following: - + OnActiveSec= OnBootSec= @@ -128,7 +128,7 @@ 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 +141,7 @@ 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 @@ -160,10 +160,17 @@ monotonic clock stops too. If the empty string is assigned - to any of these options the list of + to any of these options, the list of timers is reset, and all prior assignments will have no - effect. + 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. @@ -171,23 +178,68 @@ 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. Otherwise + calendar event expressions. Otherwise, the semantics are similar to OnActiveSec= and - related settings. + 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 @@ -197,6 +249,28 @@ are named identically, except for the suffix. + + + + Persistent= + + Takes a boolean + argument. If true the service unit is + immediately triggered when the timer + unit is activated and the timer + elapsed at least once since the last + time the service unit has been + triggered by the timer unit. The time + when the service unit was last + triggered is stored on disk. This is + useful to catch up for missed timers + when a machine is shutdown temporarily + and then is powered up again. Note + that this setting only has an effect + on timers configured with + OnCalendar=. + + @@ -208,7 +282,9 @@ systemd.unit5, systemd.service5, systemd.time7, - systemd.directives7 + systemd.directives7, + systemd-system.conf5, + prctl2