[ntp:questions] ntpd losing sync

Dave Hart hart at ntp.org
Mon Feb 6 09:12:06 UTC 2012

On Mon, Feb 6, 2012 at 08:35, A C <agcarver+ntp at acarver.net> wrote:
>> You might also consider switching from gpsd/shm + atom/pps to using
>> NMEA directly -- at least for testing, if other avenues of diagnosing
>> the problem prove fruitless.
> I'll try the splitter this coming weekend when I have an opportunity to set
> up a second system.  The clock on the IPX is set for UTC so no conversions
> should be necessary.

That helps, but one still needs to convert HH:MM:SS to seconds since
midnight to correlate.  If you want many eyes on the prize, do it for
us an point out the correlation of, for example, a spike_detect and
loopstats entry.

> I guess I can try NMEA for a diagnosis but actually want the GPS to be in
> SiRF binary because I planned on using the gpsd data elsewhere, too.

You ignored the "at least for testing".  Also I suspect gpsd can
operate just fine with NMEA input -- I don't see why using gpsd
implies binary.

>  Splitting the GPS to another machine will probably be easier.
> If I set up the clockstats, do I need to configure flag4 on the PPS refclock
> for it to record PPS data?

Without fudge flag4 1, refclock_atom logs nothing to clockstats.  With
that flag, it logs each offset (per second, not per poll).  I don't
know why I spend time looking at code to answer such questions.  I'm
getting fed up with handholding.

Dave Hart

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