[ntp:questions] NTPD can take 10 hours to achieve stability

unruh unruh at wormhole.physics.ubc.ca
Tue Apr 19 06:09:28 UTC 2011

On 2011-04-19, David J Taylor <david-taylor at blueyonder.co.uk.invalid> wrote:
> "unruh" <unruh at wormhole.physics.ubc.ca> wrote in message 
> news:slrniqpa40.ppu.unruh at wormhole.physics.ubc.ca...
> []
>> Well, I think someone other than the current maintainers will have to
>> port it to windows. Since windows timekeeping is not the worlds best
>> anyway, it is probably true that the extra accuracy of chrony is
>> unnecessary. It does have a command line option "like ntpq -p"
>> provided by chronyc (depending on what you mean by "like").
>> What MRTG is I do not know.
>> If you are happy with ntpd, by allmeans stay with it.
> A pity that chrony will not be offered for Windows, at least for tests to 
> see whether it lives up to its claims.  There are times when a more rapid 
> convergence would be welcome, such as the reboot of PC Molde around 13:30 
> yesterday:
>   http://www.satsignal.eu/mrtg/molde_ntp-b.html
> MRTG is a standard logging tool for network I/O which uses SNMP to produce 
> the graphs I have quoted here many times for network throughput and 
> timekeeping:
>   http://www.satsignal.eu/mrtg/performance_network.php
>   http://www.satsignal.eu/mrtg/performance_ntp.php
> I've written how to extend MRTG to monitor NTP timekeeping, and various 
> other parameters such as disk space and temperature here:
>   http://www.satsignal.eu/ntp/NTPandMRTG.html
>   http://www.satsignal.eu/mrtg/performance_howto.php
> From chronyc I would need to be able to use a simple Perl script to 
> extract the numbers to be plotted - such as the Offset in the graphs 
> above.  An easy job if the format is standardised and machine readable.

 As an example

chronyc <<EOF
Reference ID    : (string.physics.ubc.ca)
Stratum         : 2
Ref time (UTC)  : Tue Apr 19 06:07:20 2011
System time     : 0.000000264 seconds slow of NTP time
Frequency       : 117.650 ppm slow
Residual freq   : 0.002 ppm
Skew            : 0.233 ppm
Root delay      : 0.000129 seconds
Root dispersion : 0.000316 seconds


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