[systemd-devel] Logged timestamps for service do not report correct times

[Uoti Urpala]

On Wed, 2019-07-03 at 23:51 +0000, Sam Gilson wrote:
> My hypothesis is that is that our service loops for a long time (30
> min usually) while waiting for a new DHCP lease to come in, and once
> that is completed, a time sync w/NTP occurs which causes the
> ExecMainStartTimestamp to be rewritten. Why I think this is the case

I do not believe NTP time changes are relevant. Try checking the
journal to see if something triggers the start of a process belonging
to the service at the time the timestamp is reset. Enabling debug
logging for systemd might help if you don't see anything at normal
level.