[ntp:questions] losing time fast

Fritz Wuehler fritz at spamexpire-201207.rodent.frell.theremailer.net
Fri Jul 13 18:15:51 UTC 2012


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

> a) Stop ntpd (as mentioned above)
> b) check the config file to make sure it's configured to use a drift file,
> and find the location of it

Did that, and everything "appeared" normal.

> c1) set both minpoll and maxpoll to 6 (64 seconds) if polling the internet
> c2) set both minpoll and maxpoll to 4 (16 seconds) or 3 (8 seconds) if
> polling the LAN or a GPS

Did not know about these parameters, will read the man page and adjust.

> d) delete the drift file (as mentioned above)
> e) find the startup script for ntpd, which might be in the /etc/init.d or similar folder, is probably named NTP, and see what parameters it uses, and make a backup of it
> f) edit the startup script with elevated privileges (ie sudo, if applicable)
> g) insert the parameter (which I cannot remember the letter of) which
> allows ntpd to step the time at first

This is the default but thank you for mentioning it.

> h) save the startup script
> i) sync to a national time standard server for his country 3 times in
> quick succession with ntpdate set to make a step change (In the USA, I
> would use NIST.)

I have been using asia.pool.ntp.org

> j) start ntpd back up
> k) let if run several hours
> l) this should set a valid drift file and reign in the clock speed fairly rapidly
> m) stop ntpd
> n) reset the startup script to the way it was unless you want to leave the step command in there
> o) reset the config file for the original minpoll and maxpoll

Was taking the defaults.

> p) restart ntpd
> 
> Hopefully after a few more hours of running, the clock will be stable.
> You can even put the stop ntpd, ntpdate, ntpdate, ntpdate, start ntpd
> sequence in your own script and run that for greater speed and accuracy of
> the ntpdate sequences and minimal delay restarting ntpd. 

Unfortunately, this did not help. I tried all manner of corrections without
rebooting the box and I finally decided to do that and I am now syncing to
other machines in my network and all is fine. However since those other
machines have essentially the same ntp.conf as the one with the problem and
since they are all using the exact same server pool I do not understand why
rebooting the PC helped. I will revert to my original ntp.conf on the
problematic PC and see if it does it again. Thanks for your post.

Fritz



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