[ntp:questions] losing time fast

unruh unruh at invalid.ca
Sat Jul 14 21:51:15 UTC 2012


On 2012-07-13, Fritz Wuehler <fritz at spamexpire-201207.rodent.frell.theremailer.net> wrote:
> "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
>

As I mentioned, one possibility was that for some reason your machine
totally screwed u p the calibration of the system clock. That occurs on
bootup. So, one possibility is that on bootup now, the system calibrated
properly. 



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