How to disable systemd's "Time has been changed" message spam in /var/log/syslog on Debian jessie?

Question

Due to combined use of Debian jessie, that uses systemd by default, and sdwdate (that uses Slow Clock Adjuster ( gh )), my system clock is frequently changed.

As a result /var/log/syslog gets endlessly spammed by.

[...]
Aug 22 13:06:15 host systemd[1]: Time has been changed
Aug 22 13:06:16 host systemd[1]: Time has been changed
Aug 22 13:06:16 host systemd[852]: Time has been changed
Aug 22 13:06:17 host systemd[852]: Time has been changed
Aug 22 13:06:17 host systemd[1]: Time has been changed
Aug 22 13:06:18 host systemd[1]: Time has been changed
[...]

Running sudo service rsyslog stop stops the spam, but this is not a real solution.

This was not an issue on Debian wheezy that used sysvinit.

How can systemd be configured to not send the Time has been changed message to /var/log/syslog?

Related:
How to disable systemd's “Time has been changed” message spam in systemd journal while using sdwdate?

Answer 1

Assuming you're using rsyslog for your logging I'd add a filter there to omit these messages. I looked for a method to disable these on the systemd and did not find anything that looked like a promising lead.

:msg, contains, "Time has been changed" ~

You can put this into a file under /etc/rsyslog.d/time_msgs.conf. Be sure to restart rsyslog afterwards.

$ sudo service rsyslog restart

References

• Discarding unwanted messages -rsyslog