Thanks Dave. I have some realtime processes on this server and 128ms is too much for stepping. But thanks for the hint now I have some start point to investigate
2012/6/7 Dave Hart <h...@ntp.org> > On Wed, Jun 6, 2012 at 6:07 PM, Paul Malishev <p.malis...@gmail.com> > wrote: > > Hello. > > > > I have two ntpd peers which exchange time between themselves and also > > receive time from external server. > > I believe that at some moment connection to external server was lost and > > time on these two peers drifted a bit. > > > > When connection to external server was restored both ntpd on both peers > > logged something like: > > Jun 5 13:21:09 peer0 ntpd[5052]: frequency error 18158 PPM exceeds > > tolerance 500 PPM > > > > After that there were a lot of messages with not so big freq error: > > Jun 5 13:23:18 DIG ntpd[5052]: frequency error 608 PPM exceeds tolerance > > 500 PPM > > > > When an operator saw time difference with external server about 30sec he > > just restarted ntpd on both nodes and surprisingly freq error messages > > disappeared. Now difference is about 1ms and stability stays about 0.021 > > > > So my question is: is it possible to confuse ntpd's freq error > measurement > > with some wrong settings? > > ntpd measures the frequency error directly only at startup, lacking a > driftfile. While it's operating, it's not measuring the frequency > error, but rather manipulating it to steer the clock offset toward > zero. That manipulation is capped at 500 parts per million relative > to the nominal clock rate. > > > My config is: > > tinker step 0 > > You've told ntpd to never step the clock to correct it (by default, it > is stepped when the offset exceeds 128ms). So instead, ntpd must > eliminate slowly by running the clock faster or slower (but not more > than 500 PPM faster or slower). The large frequency "error" in the > messages is a direct result of the perceived local clock offset. > > Likely restarting ntpd also invoked ntpdate, which stepped the clock > so it was close enough that after restarting, ntpd's rate adjustments > were well under 500 PPM. > > Cheers, > Dave Hart > _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
