[ntp:questions] problem with ntpd refclock and pps via parallel port

unruh unruh at wormhole.physics.ubc.ca
Thu Feb 4 16:29:35 UTC 2010

On 2010-02-04, David Lord <snews at lordynet.org> wrote:
> unruh wrote:
>> On 2010-02-04, David Lord <snews at lordynet.org> wrote:
>>> unruh wrote:
>>>> On 2010-02-03, David Lord <snews at lordynet.org> wrote:
>>>>> Hal Murray wrote:
>> ...
>>>> Three possibilities. 
>>>> a) if you run linux/bsd, run chrony. It corrects for temp drifts much
>>>> much faster. 
>>> That's out at moment as chrony isn't sufficiently stable and
>>> backwards compatible. From my tests, I'd say offsets are lower
>> Which version of chrony? It has received extensive alteration in the
>> past few months, and chrony 1.24 is just coming out. 
> 1.23, but my brief checks with 1.24pre indicated a further improvement.
>>> than ntpd by at least a factor of 3. Problem is monitoring
>>> with chronyc requiring same version on remote as chronyd on
>> Yes, because of all the changes the chronyc and chronyd must be the same
>> version. 
> That's a bit too much of a complication for me. I'd need to
> setup build systems for older versions of NetBSD I'm
> phasing out but might still be in use for a while.

?? The above was a comment on the versions of chronyd and chronyc, not
of NetBSD. You can run the new chrony on the older versions of BSD, or
are you having trouble compiling them?

>>> server. I've also had complete lockups when attempting to peer
>>> chrony with ntpd.
>> That is much more serious. Note that I have been running 10 chrony
>> machines from one ntp server for the past 2 years and have never seen a
>> lockup. Can you give more information, at least to
>> chrony-dev at chrony.tuxfamily.org
> When I'm getting mails from new list I'll resend my my
> original report but I've moved desktops and notebooks back
> to ntpd. I've found using ntpd -q and having iburst on one
> or more sources, I can get to within a few ms within 5-10
> minutes of startup. On NetBSD chrony can't do any better at
> startup as RTC features aren't available so far as I can
> tell.

No, but you can use the initslew directive in chrony.conf to tell the
machine to step initially rather than slew initially if the time is out
by more than x seconds as determined from the intial ntp packets. 

> .....
> David

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