X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsystemd.timer.xml;h=484287ccf67fc3f770f6883e8f7df6039e8b4d3e;hp=0b204353f410643b050a11adb4c525ea2520ccc1;hb=85feb8e4d9b0ef65c338e1a1a16665d0cb8d544a;hpb=5430f7f2bc7330f3088b894166bf3524a067e3d8 diff --git a/man/systemd.timer.xml b/man/systemd.timer.xml index 0b204353f..484287ccf 100644 --- a/man/systemd.timer.xml +++ b/man/systemd.timer.xml @@ -44,18 +44,18 @@ systemd.timer - systemd timer configuration files + Timer unit configuration - 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= @@ -105,7 +105,7 @@ OnUnitActiveSec= OnUnitInactiveSec= - Defines timers + Defines monotonic timers relative to different starting points: OnActiveSec= defines a timer relative to the moment the timer @@ -115,7 +115,7 @@ 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 +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 @@ -139,8 +139,8 @@ seconds. Example: "OnBootSec=50" means 50s after boot-up. The argument may also include time units. Example: - "OnBootSec=5h 30min" means 5 hours and 30 - minutes after boot-up. For details + "OnBootSec=5h 30min" means 5 hours and + 30 minutes after boot-up. For details about the syntax of time spans see systemd.unit5. @@ -152,13 +152,86 @@ elapse and the configured unit is started. This is not the case for timers defined in the other - directives. + directives. These are monotonic timers, independent of wall-clock time and timezones. If the computer is temporarily suspended, the 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 are not + necessarily expired at the precise + time configured with these settings, + as they are subject to the + AccuracySec= + setting below. + + + + + OnCalendar= + + Defines realtime + (i.e. wallclock) timers with calendar + event expressions. See + systemd.time7 + for more information on the syntax of + calendar event expressions. Otherwise + the semantics are similar to + OnActiveSec= and + related settings. + + Note that timers are not + necessarily expired 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 + expire 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= @@ -166,7 +239,7 @@ 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 @@ -185,7 +258,11 @@ systemd1, systemctl8, systemd.unit5, - systemd.service5 + systemd.service5, + systemd.time7, + systemd.directives7, + systemd-system.conf5, + prctl2