time drift

[Chuck Swiger]

On May 15, 2008, at 12:53 PM, Volker Jahns wrote:
>> While you should run ntpdate -b at system boot, running ntpdate
>> periodically via cron is not the right thing to do-- you should run
>> ntpd instead, and that will figure out the intrinsic correction your
>> chosen system clock needs to keep better time via the ntp.drift file.
>
> Running ntpd on this system results in time drift of approx. 1-2 hrs  
> a day. That is not an acceptable option.

Something's probably wrong with your hardware clock or there is  
something else going on, if it is really drifting at ~ 5% from real  
time.  Sometimes replacing the battery on the motherboard fixes this.   
Does "vmstat -i" show exceptional interrupt load or anything like that?

>> You should also take a look at the output of "sysctl
>> kern.timecounter", and possibly switch to a different mechanism, if
>> the existing choice doesn't work out well for your machine...
> Thanks for the hint.

Indeed, try using one of the other timesources and see whether that  
corrects the huge offsets you are reporting.

-- 
-Chuck