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How are time spans defined in systemd timer?
For details about the syntax of time spans, see systemd.time(7). If a timer configured with OnBootSec= or OnStartupSec= is already in the past when the timer unit is activated, it will immediately elapse and the configured unit is started. This is not the case for timers defined in the other directives.
How to view all started timers in systemd?
To use a timer unit enable and start it like any other unit (remember to add the .timer suffix). To view all started timers, run: To list all timers (including inactive), use systemctl list-timers –all. The status of a service started by a timer will likely be inactive unless it is currently being triggered.
When to disable defaultdependencies option in systemd.timer?
Only timer units involved with early boot or late system shutdown should disable the DefaultDependencies= option. Timer units with at least one OnCalendar= directive acquire a pair of additional After= dependencies on time-set.target and time-sync.target, in order to avoid being started before the system clock has been correctly set.
What does the suffix timer mean in systemd?
Timers are systemd unit files with a suffix of.timer. Timers are like other unit configuration files and are loaded from the same paths but include a [Timer] section which defines when and how the timer activates. Timers are defined as one of two types:
How to set accuracysec in systemd timer freedesktop?
As mentioned above AccuracySec= defaults to 1 minute and RandomizedDelaySec= to 0, thus encouraging coalescing of timer events. In order to optimally stretch timer events over a certain range of time, set AccuracySec=1us and RandomizedDelaySec= to some higher value. Takes a boolean argument.
When does the timer start and when does it end?
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.
How to create a timer in systemd.timer freedesktop?
For example, by combining OnBootSec= and OnUnitActiveSec=, it is possible to define a timer that elapses in regular intervals and activates a specific service each time. Moreover, both monotonic time expressions and OnCalendar= calendar expressions may be combined in the same timer unit.