ec68e3d993644c95b8de1dfe0757fd1a by 2025

Author:2025
Language: eng
Format: epub

Chapter 7 analyzing systemd Calendar and time spans

[ 6269.847404] testvm1.both.org systemd[1]: Finished

sysstat-collect.service - system activity accounting tool.

[ 6269.846450] testvm1.both.org audit[1]: SERVICE_START pid=1

uid=0 auid=4294967295 ses=4294967295 msg='unit=sysstat-col>

[ 6269.847449] testvm1.both.org audit[1]: SERVICE_STOP pid=1

uid=0 auid=4294967295 ses=4294967295 msg='unit=sysstat-coll>

[ 6869.775575] testvm1.both.org systemd[1]: Starting

sysstat-collect.service - system activity accounting tool...

[ 6869.871332] testvm1.both.org systemd[1]: sysstat-collect.

service: Deactivated successfully.

[ 6869.871678] testvm1.both.org systemd[1]: Finished

sysstat- collect.service - system activity accounting tool.

<SNIP>

Be sure to read the journalctl man page for, among other things, a

complete list of the timestamp format options.

Time Spans

Time spans are primarily used in systemd timers to define a specific span

of time between events. This could be used to trigger events so that they

occur a specified amount of time after system startup or after a previous

instance of the same event. A sample expression to trigger an event 32

minutes after system startup would look like this in the timer unit file.

OnStartupSec=32m

The default accuracy for triggering systemd timers is a time window

starting at the specified time and lasting for one minute. You can specify a

narrower trigger time span accuracy to within a microsecond by adding a

statement like the following one to the Timer section of the timer unit file:

AccuracySec=1us

191

Chapter 7 analyzing systemd Calendar and time spans

EXPERIMENT 7-3: EXPLORING TIME SPANS

the systemd-analyze timespan command can help ensure that you are

using a valid time span in the unit file. the following samples will get you

started:

# systemd-analyze timespan 15days

Original: 15days

μs: 1296000000000

Human: 2w 1d

# systemd-analyze timespan "15days 6h 32m"

Original: 15days 6h 32m

μs: 1319520000000

Human: 2w 1d 6h 32min

experiment with these and some of your own:

• “255days 6h 31m”

• “255days 6h 31m 24.568ms”

Time spans are used to schedule timer events a specified interval

after a defined event such as startup. Calendar timestamps can be used to

schedule timer events on specific calendar days and times either as one-

offs or repeating. Timestamps are also used on systemd journal entries

although not in a default format that can be used directly in tools like

systemd-analyze.

192

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.