On 2012-02-03, David Lord <[email protected]> wrote: > David Woolley wrote: >> David Lord wrote: >> >>> >>> I've just added the "minpoll 4 maxpoll 4" back to my ntp.conf >>> as it could reduce the 30 usec offset blips I get when logs are >>> rotated. >> >> That's almost certainly totally the wrong thing to do. If you have >> short periods of increased interrupt latency or network latency, you >> want a long poll interval so that the samples with the high offsets (and >> delays) are ignored. >> >> Forcing a short interval will make ntpd track the temporary errors in >> the time measurements. >> >> Offset is not a direct measure of the timekeeping error. > > I already know that the system can't correct for temperature > changes, as with poll interval 10, and no PPS, the offset will > just carry on increasing until stepped or until the temperature > change is reversed. If the cause of these blips is down to > temperature I'd expect the shorter poll interval to be better. > I'll leave it at "4" for a couple of days then have another few > days with poll increased to "8". > > > The blips are nearly always present, 15u up to 40u.
Just looking at my system, and I get blips of up to 20 in the difference in offset from one second to the next as well. No idea why such huge differences. > > > David _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
