| Re: [chrony-users] 'fallbackdrift' and temporarily connected ref-clocks |
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- To: chrony-users@xxxxxxxxxxxxxxxxxxxx
- Subject: Re: [chrony-users] 'fallbackdrift' and temporarily connected ref-clocks
- From: Miroslav Lichvar <mlichvar@xxxxxxxxxx>
- Date: Mon, 20 Jul 2020 09:11:55 +0200
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On Fri, Jul 17, 2020 at 10:57:44AM -0600, simon@xxxxxxxxxxxxx wrote:
> I am confused about 'fallbackdrift'; if my understanding is correct the
> above will cause the real time drift corrections from 'LTC' will be dropped
> between 16s and 32s.
>
> Q. Is this understanding correct?
The average frequency offset will be applied at 16s and 32s after the
last update of the clock. You would probably want to use a much longer
interval, one that covers daily temperature changes, etc.
> Q. Is there a better way to handled a disappearing ref-clock?
For a start, I'd recommend to disable the fallbackdrift, enable the
tracking log, and let it run for a day with the refclock to see how
the frequency is changing over time.
> Q. Is there a (better?) way to confirm drift compensation source?
The tracking log will show you the corrections as they are applied.
> Some (considerable) time later, I can see that local time has drifted off.
What are your requirements? Don't expect miracles with an ordinary
computer clock.
--
Miroslav Lichvar
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