Drift is currently at -2.3, and no abnormally high/low values have been
recorded.
Loopstats collection has been on since the beginning. From the period
where these big adjustments happen, I get some suspicious data:
56269 38100.218 0.000000000 19.486 0.000000238 0.120120 9
56269 38105.421 -0.054125528 19.486 0.019136264 0.112362 9
56269 38109.421 -0.054433286 19.486 0.017900666 0.105105 9
56269 39160.464 -0.072777326 19.415 0.017956687 0.101492 9
56269 41770.153 0.000000000 19.415 0.000000238 0.094937 9
56269 41775.482 -0.002025903 19.415 0.000716265 0.088805 9
56269 41905.412 -0.044579941 19.409 0.015060036 0.083092 9
56269 43888.511 -0.066275609 19.287 0.016040319 0.088960 9
56269 47068.130 0.000000000 19.287 0.000000238 0.083214 9
The 0 offsets suggest ntpd regularly thinks we're now in perfect sync,
something which is certainly not true. I don't know how to properly
interpret the error and stability values.
and use a tool such as Meinberg's NTP Time Server Monitor or my own NTP
Plotter to display the results:
http://www.meinbergglobal.com/english/sw/ntp.htm
http://www.satsignal.eu/software/net.htm#NTPplotter
Not to look a gift horse in the mouth, but the fact that your plotter
has drag and drop for input is annoying. This (to me) is one of the
least convenient mechanisms for providing input. Since the plotter
cannot meaningfully run without input, you might as well throw an Open
File dialog up when it starts. And/or use the Windows convention of
supplying a File -> Open menu. I had to actually look in the readme to
even realize it used drag and drop at all.
The lack of feedback doesn't help either. When I drag peerstats.20121209
it's accepted but nothing happens, but it doesn't tell me why not.
(Experimentally, the reason is that you must drag all files
simultaneously, and the set must contain loopstats. Dragging peerstats
individually never does anything, whether before or after it's already
seen loopstats.)
As far as the results go, practically all the graphs look crazy, with
enormous spikes (as you'd imagine). I'll have to do more research before
I can meaningfully interpret them.
I would recommend moving to the newer pool directive rather than the
older
multiple pool server lines:
http://www.satsignal.eu/ntp/setup.html#pool
as it may use more pool servers than you would but, more importantly,
it reviews
the servers from time to time and will drop badly performing ones
(i.e. broken)
and replace them with a new one.
Thanks. For some reason, none of the documentation I've read even
mentions this directive, and that includes the setup instructions of the
pool.ntp.org website, and all manpages for ntpd.conf I've come across.
This is the first time I hear about it.
NTP will use interpolation on Windows XP and Windows-8, but normally
not in
Windows Vista or Windows-7. Yes, it can be worth experimenting with these
settings as you later report.
Does the poll increase from 64 to higher values as NTP runs, or is it
stuck on 64?
It increases all the way up to 1024.
I have seen one issue on Windows-7 where, at boot-up, NTP makes the
wrong choice
about interpolation because the system clock at that time is running
at 15.6 ms,
whereas it will later switch to 1 ms (I may have the explanation slightly
wrong). For this reason, on both my Windows-7 LAN-synced PCs I have:
NTPD_USE_SYSTEM_CLOCK=1
But I do then see: "using Windows clock directly" in the NTP events.
Yes, that doesn't appear to be the issue.
Please let us know how you get on.
The "pool" directive had some effect (I now have 9 servers instead of 4)
and initially the offset stayed under 10 ms, but it seems that as soon
as the poll interval goes above 64, the offset starts slipping --
currently at 30 ms. I'll keep things under observation; I get the
feeling it hasn't quite stabilized yet.
