On Mon, Nov 09, 2015 at 09:57:48PM +0100, Didier Kryn wrote: > Le 09/11/2015 20:12, Rainer Weikusat a écrit : > >After booting, the discrepancy between the RTC clock and the actual time > >is unknown. > I remember having had a problem with two servers when the time > discrepency reached 5mn (It was for kerberos authentication). We > discovered that one of the two was not synchronized by NTP at all. > The problem showed up after 4 years with many reboots and no clock > adjustment on the non-synchronized host. > > NTP does not adjust the RTC brutally; it seems to adjust slowly > the frequency so that synchronization happens without the process > being noticeable to other apps - it can take hours. On shutdown it > saves the RTC settings in /var/lib/ntp/ntp.drift, and (AFAIU) > /var/lib/hwclock/adjtime. After some days of running NTP, your RTC > is well trimmed and does not drift much. It does not stop running > when you power-off your computer. Therefore, at startup the > discrepancy is very small - unless the battery of the RTC is dead or > you stopped the computer for a year. > > Everything above is non-authoritative; it is the result of my > own observations.
I used chrony as my NTP client. If the discrepancy between local time on the machine and the correct time, it just gave up. I/m not sure at what discrepancy this happened, but it helped a lot to explicitly set the time by my watch. Once the time was properly synced, though, chrony worked well to keep it correct. -- hendrik _______________________________________________ Dng mailing list [email protected] https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
