time problems

[Garrett Cooper]

Lowell Gilbert wrote:
> bram <bram at diomedia.be> writes:
>
>   
>> Hi all,
>>
>> I am running 6.1-RELEASE-p2-AMD64 on a dual AMD opteron system.
>> Lately (after installing a twa-3ware raid controller I think) time
>> just stops.
>> We leave at work one evening and the clock is set ok.
>> The next morning the clock is set at 3 o'clock instead of 8 o'clock,
>> sometimes there is no clock anymore,
>> when we type date, it just returns to the next line without any output
>> whatsoever.
>>
>> This is very annoying, I've set a crontab task every 5 minutes to
>> re-update the date but it does not help (wich leads to my believe that
>> time has stopped).
>>
>> So, what could this be, and can I work around the problem ?
>>
>> Every service this machine runs stops working at such a time (no ssh
>> etc), the local keyboard still works.
>>     
>
> Hmm.  My first guess would be interrupt problems, most likely with the
> timer interrupt itself but possibly something else interfering with it.
> Keep an eye on 'vmstat -i'.
>   
Time skew might be caused by a dead CMOS battery (in particular this 
seemed like a bigger issue with my P4 than it was with my P1 once the 
battery died -- it would lose 5 minutes every couple hours or so).

Some vendors are lame too and ship motherboards with dead batteries (or 
the voltage in them dissipates over time because of parasitic impedances 
in the area).
-Garrett