[ntp:questions] Re: Solairs 8 xntpd client oscillates (now with Q for ntp 4)

Joachim Schrod jschrod at acm.org
Wed May 10 17:00:13 UTC 2006

Brian Utterback wrote:
> Richard B. Gilbert wrote:
>> Alternatively, you could ask Sun for support (and pay for it).
> Well, lets not go that far 8-). As we have stated in this forum
> in the past, all support here is best effort, and some of us are
> welling to expend that effort in directions that others are not.

Thanks a lot, Brian; I really appreciate your engagement. I have to admit that I 
don't have a support contract for that small workstation, though we have it for 
the larger servers. (But there xntpd is working...)

I added "disable pll" and "slewalways yes" to my ntp.conf and started it anew. 
After a one lost synchronizations, it stabilized and doesn't loose it any more 
for 6 hours, by now. But the offsets do not decrease:

10 May 11:44:21 xntpd[1787]: offset 0.235037 sec freq 389.284 ppm poll 6
10 May 12:44:21 xntpd[1787]: offset 0.234979 sec freq 389.284 ppm poll 6
10 May 13:44:21 xntpd[1787]: offset 0.234953 sec freq 389.284 ppm poll 6
10 May 14:44:21 xntpd[1787]: offset 0.235356 sec freq 389.284 ppm poll 6
10 May 15:44:21 xntpd[1787]: offset 0.235206 sec freq 389.284 ppm poll 6
10 May 16:44:21 xntpd[1787]: offset 0.235293 sec freq 389.284 ppm poll 6
10 May 17:44:21 xntpd[1787]: offset 0.235244 sec freq 389.284 ppm poll 6
10 May 18:44:21 xntpd[1787]: offset 0.235323 sec freq 389.284 ppm poll 6

(I deleted ntp.drift before, to make sure that I start with a clean slate.)
The offsets don't decrease, but seem to go up and down in that 235ms sec range. 
This is my current ntpq -p output:

      remote           refid      st t when poll reach   delay   offset    disp
*lion.npc.de     ptbtime1.ptb.de  2 u    -   64  377     0.46  235.342    0.02

The timeserver is stable, just to mention that. It is synchronized to its 
primaries with an offset of <10ms (that's monitored) and serves our other 
systems without problems.

I can make the statistics files (loopstats and peerstats) available, if that 
would further the case.

This is my ntp.conf (w/o comments, to keep the post smaller):
server            # IP address of server
driftfile /etc/inet/ntp.drift # path for drift file
slewalways yes
disable pll
logfile   /var/log/ntp          # alternate log file
logconfig =all
statsdir /var/ntp/ntpstats/             # directory for statistics files
statistics loopstats peerstats clockstats
filegen peerstats  file peerstats  type day enable
filegen loopstats  file loopstats  type day enable
filegen clockstats file clockstats type day enable

If somebody doesn't tell me that I made an error there; I seem not to advance my 
situation with that try. So I'm about to try the next thing: I fetched ntp 4.2.0 
from sunfreeware. And promptly appears my next question. :-)

Let me first thank you for your explanation of disable pll and why I might need 
it. In the documentation of 4.2.0 "disable pll" is not mentioned, and also not 
slewalways. Is that discussion of relevance for the reference NTP server? I 
don't think so because it all depended on the compilation option SLEWALWAYS used 
in Sun's xntpd. Is that option still in 4.x, and can I query ntpd for its 
compilation options?


PS: Yesterday evening I was in a pub with a German Sun SE, Ulrich Graef; whom I 
also told about that problem and he just remarked "Brian Utterback -- oh yes, 
he's a very competent and very nice guy". I can only agree to that... :-) :-)

Joachim Schrod				Email: jschrod at acm.org
Roedermark, Germany

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