Re: [chrony-users] chrony losing sync with GPS reference

[Bill Unruh <unruh@xxxxxxxxxxxxxx>]

On Wed, 5 Dec 2018, Brendan Simon (eTRIX) wrote:

> I'm running Debian Linux (Jessie based with a few backport packages) on some embedded systems that use a GPS
> receiver to set the system clock.
>
> The problem I have seen is that the chrony loses sync with the GPS reference after some time, and the system clock
> starts to drift and never recovers.  This is disastrous as I need to have the clocks synchronised.
>
> gpsd was restarted and then chrony started synchronising the system clock again.
>
> gpsd is 3.16 (jessie-backports) and chrony is 1.30 (jessie)

I think more information is needed. Make sure that the "refclocks" logs are
enabled, and look at them when the clock loses sync to see what is happening.
Are you using PPS or just the UTC time stamos from theGPS?
.


> Is there anything in chrony 1.30 that could be known to cause this loss of sync with no recovery ever?
>
> Is there anything in gpsd 3.16 that could be known to cause this loss of sync with no recovery ever?
>
> I'm looking at moving to Debian Buster (still in Testing but to be released early 2019).  It has gpsd 3.17 (but
> hopefully might move to 3.18 before release) and chrony 3.4.
>
> Does anyone know if this latter combination of gpsd/chrony is likely to solve the issues/symptoms described above?
>
> gpsd changelog isn't too informative with fixes.  I see the following:
>
> 3.18: Fix several buffer issues.
>       Too many other bug fixes and improvements to mention.
>
> 3.17: Fix a SiRF driver bug that occasionally confused NTP.
>
> \Thanks,
> Brendan.
>
> --
>
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