[ntp:questions] A faster settling NTP

David Lord snews at lordynet.org
Fri Dec 25 11:15:25 UTC 2009


David J Taylor wrote:
> 
> "unruh" <unruh at wormhole.physics.ubc.ca> wrote in message 
> news:slrnhj7qd9.3p4.unruh at wormhole.physics.ubc.ca...
> []
>>> Why not take a different approach, then?  Start with chrony to make the
>>> system rapidly stable, and then turn control over to NTP.  Is something
>>> like that possible?
>>
>> Why not just stick with chrony. But I thought we were discussing Windows
>> systems, on which chrony does not run. And if someone has rewritten
>> chrony to run on windows, there is no point in handing over to ntp. As I
>> said chrony is about 2 times better ( lower standard deviation) than
>> ntp. Why would you want to hand over control to a worse program?
> 
> I had wondered whether that might be an acceptable solution for some 
> folk. My original question was not OS-specific.  As you say, until 
> chrony is available for a wider range of operating systems and supports 
> GPS/PPS reference clocks it is but of academic interest.  As NTP already 
> provides that infrastructure, enhancing the initial convergence rather 
> than having to re-invent the whole wheel seems a better approach to me.

When I first made use of chrony it was to keep time with
only occasional access to internet. There was no NetBSD
specific package at the time but enough guidance was
available to get it built and working. Ntpd was in
default base OS and I'd tried and failed to get that
working with dialup and maintain reasonable time between
connections. Chrony already came with configuration
examples just for this and apart from initial problems
getting it to build it worked very well for several years
on dialup then another few years on broadband. Two
fileservers running ntpd were happy to use the firewalls
as sources. So I'd not put it down as only of academic
interest.

I agree that from my non programmer point of view it
would seem that making changes to ntpd to import those
features from chrony would be easier than making changes
to chrony but I suspect lack of interest in that
direction or in developing a windows version of chrony.

David




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