Re: 7200 clock

[kevin@vanhaaren.net (Kevin van Haaren)]

On Mon, May 07, 2001 at 10:03:13AM -0700, David J. Roundy wrote:
> On Mon, May 07, 2001 at 11:24:18AM -0500, Kevin van Haaren wrote:
> >
> > Not really a debian issue, but does anyone else with a 7200 have serious
> > clock issues?  Bascially I'm losing 12 seconds every 10 minutes.  Through
> > a stupid ipchains firewall scripting error i blocked my NTP access on
> > Friday.  When I fixed it earlier today it was off by 443 seconds.
> > 
> > Is this hardware failure or are all 7200 clocks that crappy?
> > 
> > Guess I'll try replacing the PRAM battery first.
> 
> My guess is that the problem was just ntp.  ntp sets the clock skew in
> order to adjust the clock, so if you lost ntp access while ntp was in the
> process of setting the clock back, it would continue running slowly until
> you regained access to ntp.

I don't think it's just that because it was dropping 12 seconds every 90 minutes (I said 10 before, that was wrong).  Here's what I saw in my logs before I screwed up the firewall:
May  4 11:50:51 bubbles ntpd[149]: time reset -13.494621 s
May  4 11:50:51 bubbles ntpd[149]: synchronisation lost
May  4 13:16:10 bubbles ntpd[149]: time reset -13.064225 s
May  4 13:16:10 bubbles ntpd[149]: synchronisation lost
May  4 14:41:21 bubbles ntpd[149]: time reset -10.888137 s
May  4 14:41:21 bubbles ntpd[149]: synchronisation lost
May  4 16:23:20 bubbles ntpd[149]: time reset -12.223887 s
May  4 16:23:20 bubbles ntpd[149]: synchronisation lost
May  4 17:48:45 bubbles ntpd[149]: time reset -11.726727 s

Now that I fixed the firewall it's back to resetting the clock -12 seconds every 90 minutes

neither my Superman C500 nor Intel box sees those kind of numbers.

> 
> I don't think the PRAM battery could be responsible, since as I understand
> it, the hardware clock which is maintained by battery is only consulted on
> reboot, and as I understand matters you didn't reboot.

Yes, that was my thought too, and this box is never shut off.  But it's the only thing I can think of to try (or a bad clock chip).