[ntp:questions] ARRGH!!! I woke up to a 50 SECOND clock error.
Chris Albertson
albertson.chris at gmail.com
Tue Mar 13 18:40:36 UTC 2012
On Tue, Mar 13, 2012 at 9:52 AM, Ron Frazier (NTP)
<timekeepingntplist at c3energy.com> wrote:
> Hi all,
>
> I just woke up to a 50 SECOND clock error. Prior to the error, with my PC
> locked into the GPS and the internet servers noselected, here's what my
> peerstats looked like. Baseline is the GPS. Colored lines are internet
> servers.
>
> http://dl.dropbox.com/u/9879631/drifting01-peerstats.20120312.jpg
Looks to me like that GPS, maybe lock lock and was able to "coast" on
hold over for a while then fell off a cliff. If you have a log of
satellite signal to noise ratios you might be able to figure out why.
The internet servers appear to be 100% reliable seeing as they all agree.
These kinds of things are why some hobbysts end up buying multiple GPS
(different brands) Otherwise it is hard to sort out a GPS firmware
bug from a solar storm or just that there were not sats visable to
your indoor antenna for a few minutes
I think your goal is to learn about all of this so these problems are
a good thing. No one learns much from working systems. But if the
goal is a reliable NTP server, the pool NTP servers can't be beat
except by a good timing mode GPS, that has good self diagnostics and
PPS. The self diagnostics part is important
--
Chris Albertson
Redondo Beach, California
More information about the questions
mailing list