[ntp:questions] Using both Server and Peer in ntp.conf

Uwe Klein uwe_klein_habertwedt at t-online.de
Thu Feb 8 20:25:45 UTC 2007

Hal Murray wrote:
>>How many minutes, hours, or days of "holdover" with reasonably correct 
>>time you may get depends on the quality of the local clock, the 
>>stability of the temperature, the phase of the moon and the whims of the 
> We can at least do a bit of arithmetic.
> There are 86400 seconds in a day.  If your clock is off
> by 11 ppm, it will drift 1 second per day.
> If your machine is in an airconditioned machine room, the
> average temperature is probably pretty stable.  I'd guess
> a second per week would be conservative.
> If your machine is in an environment with poor temperature
> regulation, the day to day average temperature is probably
> the important consideration.
Yes it works that way, I have systems ( embedded, linux + RT )
running in a reasonably climatised room that have to do exactly
18000 sample cycles per 30min interval. When I have fixed
the timer value to make it fit I can leave it alone for quite
some time : weeks, month,..

But I get an imediate error when the gas tank for the heating is
empty ;-)

To return to my question:
Does ntpd follow this deterioration in any way?


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