[ntp:questions] PSYCHO PC clock is advancing at 2 HR per second
davehart at gmail.com
Tue Mar 20 04:11:43 UTC 2012
On Tue, Mar 20, 2012 at 03:56, Ron Frazier (NTP) wrote:
> Hi Dave H,
> Thanks for the info and for looking into the issue. I meant that the clock
> was psycho, not the PC.
Right, I got that. You were ever so politely screaming for attention
regarding software I volunteer to help maintain. How may I snap to
> The PC is normally very tame and cooperative, as cooperative as Windows
> gets anyway. These GPS experiments have certainly brought several
> surprises though.
> I run both Windows and Ubuntu Linux, but in this case, the system is:
> Windows 7 Home Premium SP 1
> NTPD 4.2.7p259
> LOCL has been removed. However, that brings up a question. Since I'm doing
> tests with the internet clocks noselected (but still monitoring them), and
> the GPS is the only selectable clock, what happens if it becomes invalid?
> The whole reason I put LOCL in there was to allow the machine to "coast" if
> the GPS signal became invalid.
The behavior of the local clock discipline is not any different with
no selectable sources than with only the LOCAL driver selectable.
Where it makes a difference is clients will not continue to follow a
ntpd server which has no selectable sources, but will follow one using
LOCAL as a fallback. Your machine will freewheel the same either way.
Only clients will care about the difference, and if that's an issue,
orphan mode may provide a more resilient solution.
Still, as much as I doubt using the LOCAL clock driver is optimal for
you, I know a lot of people are in the habit and want ntpd to behave
well even when that driver is in use, regardless of my opinion of its
utility in that case :)
> How would I go about checking the event log?
Using the Event Viewer, eventvwr from a command line or right-click on
Computer and select Manage.
> On 3/19/2012 10:59 PM, Dave Hart wrote:
>> I don't know what the heck happened either, but there are a few clues.
>> You didn't tell us which version of ntpd you're using or which OS
>> it's running on. Skimming the huge ntp.conf for non-comment lines I
>> see it appears to be some version of Windows.
>> Take note of the last line in the first loopstats file you sent:
>> 56005 85287.065 -1.#IND00000 -1.#IO 0.003538719 -1.#IND00 3
>> There is no activity in the corresponding peerstats file to give a
>> hint what sent your offset and frequency off the deep end. You might
>> check the eventlog around the end of the 19th UTC to see if there are
>> any clues there.
>> Although it's the first time I've seen such, it appears the offset and
>> frequency calculations both ended up overflowing. I would have
>> guessed bad input should have appeared in peerstats before loopstats
>> but I didn't find anything unusual. It does appear the GPS was
>> unplugged or stopped sending or sent sentences indicating no lock,
>> based on the last peerstats entry for 127.127.20.5 occurring almost
>> exactly 5 minutes before the overflow event.
>> Probably we should just write it off as nominal since the PC is
>> described as psycho.
>> Take care,
>> Dave Hart
>> On Tue, Mar 20, 2012 at 01:59, Ron Frazier (NTP)
>> <timekeepingntplist at c3energy.com> wrote:
>>> Hi all,
>>> I just came home from supper to the most NOT charming experience. I had
>>> left with my PC clock syncing nicely to my Globalsat BU-353 GPS. When I
>>> came home, I found the clock said Aug 2014 and visually could see that
>>> clock was advancing at a rate of about 2 HR per actual second. The
>>> screen said it was locked into the local clock and the Meinberg screen
>>> appeared to be updating about twice per second rather than once ever 10
>>> seconds. It said that the preferred clock was LOCL 127.127.1.1. I don't
>>> know what the heck happened, but these anomalies are getting really old.
>>> Hopefully the Sure board will do better. Oh, by the way, I shut down
>>> and the clock kept advancing the same way. 2 reboots appear to have
>>> it. I've removed LOCL from the config file. Here are some links to some
>>> log and conf files if anyone is interested. Note the dates at the end.
>>> I've got 1200 log files in between these start and end dates.
>>> the date far into the future
>>> the date far into the future
>>> Sincerely Frustrated,
> (PS - If you email me and don't get a quick response, don't be concerned.
> I get about 300 emails per day from alternate energy mailing lists and
> such. I don't always see new messages very quickly. If you need a
> reply and have not heard from me in 1 - 2 weeks, send your message again.)
> Ron Frazier
> timekeepingdude AT c3energy.com
> questions mailing list
> questions at lists.ntp.org
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