[ntp:questions] losing time fast

Anonymous noreply at breaka.net
Thu Jul 12 08:49:42 UTC 2012


"Ron Frazier (NTP)" <timekeepingntplist at techstarship.com> wrote:

> Hi Unruh,
> 
> I'm glad you like the suggestions.  You may be right about the drift file.
> I don't know for sure what caused the runaway clock I experience in the
> past.  However, it's my understanding that NTP sets the computer clock
> frequency to what it finds in the drift file at startup.  If the drift
> file is way off, for whatever reason, then the initial clock frequency
> will be way off.  As far as I know, it won't write another drift file for
> an hour.  So, during that hour, particularly if the polling interval is
> long, the clock can be running so fast or slow that it will drift so far
> out that NTP might just give up on it. 

That may have been what happened because the drift file looked "normal" to
me when I checked it but the clock was just getting worse and worse, as if
ntp wasn't running. ntpdate sometimes fixed it but it would start drifting
very quickly in huge amounts, minutes until it was 45 or more minutes off.

> >Why a national time server? No need for that kind of accuracy.

As long as we are all interested in precise and accurate time, every
possible improvement that's easy to make should be worthwhile. Unfortunately
I live in a country with erratic local time servers so I use the asian pool
that has been mostly ok as far as I can tell.

Thanks.



More information about the questions mailing list