[ntp:questions] NTP not syncing

Magnus Danielson magnus at rubidium.dyndns.org
Sun Nov 3 17:26:15 UTC 2013


On 11/03/2013 12:43 AM, David Woolley wrote:
> On 02/11/13 21:48, David Lord wrote:
>
>>
>> Ntpd writes to its drift file and also ntp.log. The drift file
>> is critical and is used and updated at intervals by ntpd.
>>
> The drift file is an optimisation.  ntpd should work without it, but
> will take longer to acquire lock after a restart.
>
> What would cause more problems would be a drift file that was present,
> but read-only, as ntpd would skip its frequency calibration and trust
> the frozen value in that file, then suffer wild swings as it begins to
> discover the value was wildly wrong.
If the oscillator drifts from last drift-file write, outside of +/- 15
ppm if I recall it, it fails to lock in again.
It would be good if it could bail out and do normal frequency
acquisition if that occurs.

That particular "feature" have bitten hard, and was a side-consequence
of other faults, but none-the-less.

Cheers,
Magnus


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