Re: Kernel unable to adjust timeofday

From: Valdis . Kletnieks
Date: Fri Sep 26 2008 - 10:51:58 EST


On Fri, 26 Sep 2008 15:29:53 +0200, Rafal said:
> Hello, my system (64bit Ubuntu amd64 box) drifts about 10 seconds per hour
> (i.e. time visible in the system).

First thing to do is figure out why your box has *such* a dreadfully poor
clock. You're drifting at around 3,000 parts-per-million. NTP is only able
to deal with drifts up to 500 ppm, and most systems clocks are *much* more
stable than that (for instance, my laptop is drifting at 2 ppm at the moment).
The fact you're way outside the sane range leads to trouble...

> When I use adjtime(), or when I use ntpd that uses adjtime() then the
> adjustment is slower then the speed of drift.

... which is why you see this happen.

> The default rate of adjustment seems to be really low, can we set the
> default adjustment rate to be a higher?

The default rate is set fine. It's simply unable to deal with insane hardware
and/or software. What kernel are you running on it?

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