| Re: [chrony-users] Multi-PPS+RTC Setup Questions |
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- To: chrony-users@xxxxxxxxxxxxxxxxxxxx
- Subject: Re: [chrony-users] Multi-PPS+RTC Setup Questions
- From: Miroslav Lichvar <mlichvar@xxxxxxxxxx>
- Date: Tue, 29 Sep 2020 17:19:37 +0200
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On Tue, Sep 29, 2020 at 11:01:53AM -0400, Matt Corallo wrote:
> On 9/29/20 10:44 AM, Miroslav Lichvar wrote:
> > Try adding something like "mindelay 0.0001" to both sources.
>
> Would this also force combination of the two ala combinelimit, or only allow
> them to be selected in 3.5 when the RTC is not "trust"?
Yes, with the delay their intervals should overlap and both be
considered selectable for synchronization and then combined as their
root distance is similar.
If you are familiar with ntpd, the delay is similar to the tos mindist
setting. ntpd has this fudge by default. chronyd does not. If you have
two very precise but not so accurate sources, their intervals will
overlap only sometimes by chance and disturb the selection.
> Right, sorry, indeed. My goal was to force chrony to combine the two GPS PPS
> inputs (cause why not, and it seems strange that chrony would, by default,
> pick one and stick with it, ignoring the other...plus results show much more
> stability when they're combined =D).
Yes, that makes sense.
--
Miroslav Lichvar
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