On Mon, Nov 17, 2008 at 03:01:02PM -0500, N.J. Thomas wrote: > * Maxim Khitrov <[EMAIL PROTECTED]> [2008-11-17 14:47:00+0000]: > > > I've not seen any problems with the clock on my RootBSD Xen system. > > > I do run the ntpd in base and on average, my clock is usually only > > > about 15ms away from "true UTC". > > > > That's interesting. Can you post your `ntpq -p` output here? > > Sure: > > $ ntpq -p > remote refid st t when poll reach delay offset > jitter > > ============================================================================== > +clock.trit.net 192.12.19.20 2 u 529 1024 377 81.554 2.870 > 6.477 > +mail.honeycomb. 192.43.244.18 2 u 408 1024 377 44.091 10.986 > 8.250 > *tuppy.intrepidh 64.142.103.194 2 u 413 1024 377 67.709 15.626 > 10.327 > +clock3.redhat.c 66.187.233.4 2 u 445 1024 377 147.283 24.455 > 9.397 > +204.34.198.40 .USNO. 1 u 409 1024 377 88.746 20.620 > 10.405 > +tick.usno.navy. .USNO. 1 u 427 1024 377 20.848 18.916 > 8.212 > +ntp-s1.cise.ufl .GPS. 1 u 421 1024 377 45.709 18.067 > 9.222 > LOCAL(0) LOCAL(0) 10 l 18 64 377 0.000 0.000 > 0.004 > > This is what I pretty much used to eyeball my offset earlier. > > > When ntpd is running, its polling interval stays very low (around 64 > > seconds) because it keeps having to reset the clock. My message log is > > filled with the following: > > Intersting, I see the same in my logs, but the frequency seems to be > much less than yours, e.g. for the month of November: > > Nov 1 00:08:22 zaph ntpd[678]: time reset -0.129649 s > Nov 3 15:33:09 zaph ntpd[678]: time reset -0.137509 s > Nov 4 03:11:51 zaph ntpd[678]: time reset +0.237734 s > Nov 4 03:34:23 zaph ntpd[678]: time reset -0.150326 s > Nov 4 13:05:20 zaph ntpd[678]: time reset +0.317738 s > Nov 4 13:32:06 zaph ntpd[678]: time reset -0.560629 s > Nov 4 13:54:35 zaph ntpd[678]: time reset +0.265391 s > Nov 4 15:43:55 zaph ntpd[678]: time reset -0.163660 s > Nov 7 17:31:03 zaph ntpd[678]: time reset -0.130039 s > Nov 10 18:29:19 zaph ntpd[678]: time reset +0.169785 s > Nov 10 19:46:26 zaph ntpd[678]: time reset -0.146554 s > Nov 10 20:27:08 zaph ntpd[678]: time reset +0.891811 s > Nov 10 20:53:59 zaph ntpd[678]: time reset -0.774636 s > Nov 10 21:35:45 zaph ntpd[678]: time reset +0.384227 s > Nov 10 22:33:46 zaph ntpd[678]: time reset -0.194131 s > Nov 11 12:34:25 zaph ntpd[678]: time reset +0.433002 s > Nov 11 13:01:09 zaph ntpd[678]: time reset -0.335592 s > Nov 11 15:17:45 zaph ntpd[678]: time reset +0.933537 s > Nov 11 16:01:42 zaph ntpd[678]: time reset -0.510371 s > Nov 11 17:29:41 zaph ntpd[678]: time reset -0.133244 s > Nov 11 19:16:41 zaph ntpd[678]: time reset +0.191431 s > Nov 11 19:42:30 zaph ntpd[678]: time reset -0.458738 s > Nov 11 20:09:16 zaph ntpd[678]: time reset +0.207999 s > Nov 11 20:36:06 zaph ntpd[678]: time reset +0.143897 s > Nov 14 01:29:44 zaph ntpd[678]: time reset +0.134492 s > Nov 15 13:13:36 zaph ntpd[678]: time reset +0.199937 s > Nov 15 14:45:09 zaph ntpd[678]: time reset -0.205131 s
What time counter source does this box have available? The following will list what's being used (hardware) and what's available (choice): sysctl kern.timecounter.choice sysctl kern.timecounter.hardware Other ideas: Look into the "fudge" operator of ntp.conf. Try deleting your ntp driftfile. Note that if you do this, it will take a day or two for things to "level out". It tries to figure out the "average" skew rate your system clock has. > > And so on... Could it be a problem with the hardware on host machine? > > I use the same ntp.conf file on several FreeBSD 7.1 servers, and the > > VPS is the only one that has this problem. > > I checked on my other FreeBSD boxes (all 7.0) and none of them (VPS or > otherwise) exihibit this problem. Then there's a very good possibility it's hardware-related. At my workplace, we've had two separate machines in the past couple months had clocks which "went crazy" -- ntpd reporting 4-5 seconds of skew every 25-30 minutes. In both cases, the problem turned out to be broken/bad hardware (crystal or TSC gone bad). Just something to keep in mind. :-) -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB | _______________________________________________ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"