[ntp:questions] Can a clock drift be too big for ntpd?
pln at glast2.Stanford.EDU
Fri Oct 19 00:59:05 UTC 2007
I'm having trouble with one linux client out of a group.
It seems as if ntpd can't keep its clock syncronized. It's
drifting about 6-10 minutes per day, well over the 500 ppm limit.
After reading some of the posts on this newsgroup, I have come
to realize that debugging ntp problems can be quite complex.
Before I launch into a detailed search, I would like to clarify
one question. Is it possible for the clock frequency to be so
far off that ntpd just can't get it under control?
I have stripped my ntp.conf to the minimum, just one server
line and a drift file. The log entries look like this:
Oct 18 17:23:32 client ntpd: synchronized to 184.108.40.206, stratum 1
Oct 18 17:27:48 client ntpd: no servers reachable
Oct 18 17:29:06 client ntpd: synchronized to 220.127.116.11, stratum 1
Oct 18 17:29:16 client ntpd: time reset +10.678548 s
Oct 18 17:29:58 client ntpd: synchronized to 18.104.22.168, stratum 1
Oct 18 17:31:59 client ntpd: no servers reachable
ntpq -p says this:
remote refid st t when poll reach delay offset jitter
grandfather.Sta .GPS. 1 u 49 64 375 0.243 2833.49 1139.84
For a while there was a * in the first column, but it went away.
Did I mention that there are several other clients with no problems at all?
ntpd 4.2.2 is running with -g, burst, and iburst.
So, does this look like a hardware problem?
If not, I'll have to dig into networking and details of the configuration.
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