David, The units recorded in the frequency file are in precise parts-per-million (PPM) maintained to a precision of parts-per-billion (PPB). Properly calibrated, it makes an excellent room thermometer, fire alarm and fan tattletale.
Dave David Woolley wrote: > In article <[EMAIL PROTECTED]>, > terrypearl <[EMAIL PROTECTED]> wrote: > > >>driftfile: -21.719 > > >>good? bad ? indifferent ? > > > Without knowing the frequency error of the timing crystal in the PC, it's > impossible to say. > > What was meant by the question was: does the value in your driftfile > accurately reflect the correction needed to maintain the steady state? > > Because you are not keeping the machine up for very long at any one time, > it is possible that the drift value never properly converges, so the > value is not particularly accurate. If you didn't have a drift file at > all, or if it is unreadable to ntpd, ntpd would have spent about 15 > minutes trying to calculate the frequency error, before setting the > time. However, I'm not really sure how you define "achieve synch". > > (Also, as you say you use Linux, Linux shares, with Windows, a tendendency > to lose clock interrrupts, which can severely disrupt the ability to maintain > accurate time.) > > Incidentally, although I haven't tried it in anger, I believe that a system > with a good driftfile value will achieve low offsets faster if it is > started with an offset of more than 128ms. Below that, gentle corrections > are applied, but, above it, a step correction is applied. > > As to leaving the machine on, that is very good advice for precision time > synchronisation protocols, like NTP. We cannot know when people are > under severe financial constraints if they don't tell us. _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
