Re: [chrony-users] Discover when a time sync has been performed

[Bill Unruh <unruh@xxxxxxxxxxxxxx>]

On Thu, 4 Jul 2013, Ignacio Verona R� wrote:

> Hi Bill,
>
> yes, the rapspi is sometimes powered-off, specially now while I'm testing
> the software. No process other than chrony is modifying the time, and
> sometimes the board is powered-off for many hours (overnight), and so will
> be the real behaviour of the final app.

Ah. So you want chrony to start up with the initstepslew  directive in
chrony.conf with a low time to allow it to set itself initially. You should
sometimes leave it on for a while so that the drift file can be properly
populated. But all of the ntp programs are designed to discipline a clock over
a long period of time, not in a stop and go fashion. It is ok with chrony if
it is only connected to the net sporadically (but for the initstepslew it
should be connected when it boots up). 
> I'm thinking about buying an RTC clock. They are cheap (15�) and maybe
> connecting it to the GPIO ports help... but I'd like to stay with a pure
> software source.

The problem is that none of the program can do anything if there is no time
source of any kind. They cannot pull time out the air.

You say you have  a gps attached. Does it have PPS? or is it just the nmea
sentences? Is it also switched on when the pi is switched on or is it on
permanantly? They also take a while to get a decent time.

Ie, telling us in some detail what your situation is might allow us to give
better advice.



> 2013/7/4 Bill Unruh <unruh@xxxxxxxxxxxxxx>
>
> > On Thu, 4 Jul 2013, Ignacio Verona R� wrote:
> >
> >  Thanks again! Yes, I'm using 1.24 and now realized the log is there:
> > > Jul  3 20:39:37 m2m-probe1 chronyd[2077]: System clock was stepped by
> > >
> > > > 829.745 seconds
> > > > >
> > > >
> > > > Jul  3 21:12:49 m2m-probe1 chronyd[2023]: System clock was stepped by
> > > >
> > > > > 3057.778 seconds
> > That is looking seriously sick. It steps the clock, and 33 minutes later it
> > steps it by 50 minutes?
> >
> > > > Jul  3 21:34:59 m2m-probe1 chronyd[2108]: System clock was stepped by
> > > >
> > > > > 21.122 seconds
> > > >
> > > > Jul  3 22:46:03 m2m-probe1 chronyd[1983]: System clock was stepped by
> > > >
> > > > > 1698.671 seconds
> > > >
> > > > Jul  4 09:17:25 m2m-probe1 chronyd[2047]: System clock was stepped by
> > > >
> > > > > 32109.587 seconds
> > > > and here by 9 hours? Are constantly switching off and on you RPi?
> >
> >
> >
> > > > Jul  4 10:27:34 m2m-probe1 chronyd[1992]: System clock was stepped by
> > > >
> > > > > 36102.593 seconds
> > and an hour later by 10 hours?
> >
> > Is your program altering the clock itself?
> >
> >
> >
> >
> > > > Jul  4 13:41:12 m2m-probe1 chronyd[2015]: System clock was stepped by
> > > >
> > > > > 3942.919 seconds
> > > >
> > > >
> > > >
> > > >  Thank you very much!
> > >
> > >
> > > 2013/7/4 Miroslav Lichvar <mlichvar@xxxxxxxxxx>
> > >
> > >  On Thu, Jul 04, 2013 at 04:32:04PM +0200, Ignacio Verona R� wrote:
> > > > > Hi Miroslav,
> > > > >
> > > > > thanks for your answer. It partially solves my question, but I'm not
> > > > > able
> > > > > to see the entry in the tracking log when makestep is applied. Last
> > > > > lines
> > > > > of the file look like this:
> > > >
> > > >  2013-07-04 13:05:17 193.145.56.7     3     82.620     46.004 -2.830e-03
> > > > > > 2013-07-04 13:05:21 193.145.56.7     3     82.127     43.920 -2.164e-03
> > > > > >
> > > > > > 2013-07-04 13:05:25 193.145.56.7     3     81.555     42.269 -1.921e-03
> > > > > >
> > > > > >
> > > > > >
> > > > > >  Should I expect some "Makestep OK" message? or it's a different state?
> > > >
> > > > Not in the tracking log, but in the system log there should be a
> > > > "System clock was stepped by x seconds" message.
> > > >
> > > > From the number of columns in your tracking log it seems it's an older
> > > > version of chrony. The log message should be in 1.24 and later.
> > > >
> > > > --
> > > > Miroslav Lichvar
> > > >
> > > > --
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> > > > .
> > --
> > William G. Unruh   |  Canadian Institute for|     Tel: +1(604)822-3273
> > Physics&Astronomy  |     Advanced Research  |     Fax: +1(604)822-5324
> > UBC, Vancouver,BC  |   Program in Cosmology |     unruh@xxxxxxxxxxxxxx
> > Canada V6T 1Z1     |      and Gravity       |  www.theory.physics.ubc.ca/

--
William G. Unruh   |  Canadian Institute for|     Tel: +1(604)822-3273
Physics&Astronomy  |     Advanced Research  |     Fax: +1(604)822-5324
UBC, Vancouver,BC  |   Program in Cosmology |     unruh@xxxxxxxxxxxxxx
Canada V6T 1Z1     |      and Gravity       |  www.theory.physics.ubc.ca/