[pkg-ntp-maintainers] Bug#613819: Bug#613819: ntp: problems synchronising time on PII-266 with 2.6.38-rc? kernels

[Kurt Roeckx]

On Fri, Feb 18, 2011 at 12:21:35AM +1030, Arthur Marsh wrote:
> 
> # ntpq -np
>      remote           refid      st t when poll reach   delay   offset  jitter
> ==============================================================================
>  192.231.203.132 216.218.254.202  2 u   10   32  377   17.163  19081.2 4120.94
>  203.82.209.217  18.26.4.105      2 u   11   64  177   48.001  19086.2 11098.8
>  174.143.207.151 128.249.1.10     3 u   12   64  177  234.325  19093.2 10865.4
>  203.17.251.1    192.189.54.17    3 u    5   64  377  196.310  19419.7 11304.7
>  202.81.208.160  203.12.160.2     3 u   42   64  177   50.070  18403.6 11197.5
[...]
> I would like to find a way of keeping the time stable under 2.6.38* kernels
> on this machine (PII-266, 440BX chipset). Any constructive suggestions welcome.

I assume you didn't have a problem with older kernels?

In case like this it's ussually a kernel problem where time runs
too slow or fast and ntpd tries to correct it but the error is
too high to be able to correct it.

Looking at your output, I'd have to guess that your time goes
wrong around 5-30 ms / s.  That would be 5000 - 30000 ppm,
or 432 - 2592 s / day.  ntpd limits itself to 500 ppm.

Can you try running:
ntpdate -p1 -q 192.231.203.132 ; sleep 60; ntpdate -p1 -q 192.231.203.132

That should give as a good idea of how much it's going wrong.

Can you also run:
ntpdc -c kerni


Kurt