[ntp:questions] PSYCHO PC clock is advancing at 2 HR per second
Ron Frazier (NTP)
timekeepingntplist at c3energy.com
Tue Mar 20 04:56:38 UTC 2012
On 3/20/2012 12:11 AM, Dave Hart wrote:
> 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
> your service?
I certainly didn't mean any offense by anything I said, and apologize if
any was perceived. OK, this event freaked me out. I almost felt like
screaming. Watching the hands on the windows graphical clock image spin
rapidly around was making me wonder if the PC was haunted or something,
or had a virus, or had bad RAM, or a bad HDD, none of which I wanted to
think about. I have been very surprised with the apparent
unreliability of GPS sometimes. This one in particular seems to wander
off from UTC and have periodic heart attacks. It's been a big surprise
to me. This is strange and weird stuff to a timekeeping newbie. I
really DO appreciate your (and other people's) assistance. 8-) The
only thing I could think of to do was post the experience on the list in
case someone could shed some light on it.
>> 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 :)
LOCL is gone. Since you say the system can freewheel either way, I'll
probably leave it gone. I had specifically hoped it would prevent
problems in case the GPS went crazy. I guess I was mistaken. Since I
dual boot between Windows and Linux, eventually, I hope to have each PC
capable of using a GPS, no matter which OS is running, and one PC
designated as my master clock, no matter which OS is running. The
master clock would prefer the GPS first, then internet servers. The
other PC's would prefer the GPS first (if attached), then my master
clock, then internet servers.
Just for curiosity, is there any difference between 127.127.1.1 and
>> 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.
> Good luck,
> Dave Hart
>> 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
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timekeepingdude AT c3energy.com
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