dntpd

Matthew Dillon dillon at apollo.backplane.com
Mon Jun 25 10:27:17 PDT 2007


:No reboots and I don't have a wall_cmos_clock.  Basically...nothing changed
:afiact.
:
:Here's a grep of the past week.  That disk was replaced on the 22nd.

    Well, your machine's timebase is not very stable, even looking at
    the earliest reports.  It's not totally bogus, but it definitely looks
    like the frequency is thermally unstable.  What is it using as
    the system clock?  Do this:

	sysctl kern.cputimer

    I really can't be sure until you run dntpd with just a single server
    line, but usually the frequency adjustment is server-agnostic (won't
    ping pong around with different servers), even if the time adjustment
    does ping pong around a few milliseconds here and there.

    A stable timebase should stick to less then a 50 ppm range.

:Jun 20 19:52:41 ylem dntpd[73041]: issuing frequency adjustment: 289.730ppm
:Jun 20 21:38:19 ylem dntpd[73041]: issuing frequency adjustment: 333.651ppm
:Jun 20 23:08:22 ylem dntpd[73041]: issuing frequency adjustment: 292.546ppm
:Jun 20 23:13:39 ylem dntpd[73041]: issuing frequency adjustment: 329.224ppm
:Jun 20 23:40:03 ylem dntpd[73041]: issuing frequency adjustment: 305.610ppm
:Jun 17 15:09:15 ylem dntpd[73041]: issuing frequency adjustment: 351.922ppm
:Jun 17 16:29:21 ylem dntpd[73041]: issuing frequency adjustment: 406.836ppm
:Jun 17 21:15:01 ylem dntpd[73041]: issuing frequency adjustment: 285.856ppm
:Jun 17 23:37:42 ylem dntpd[73041]: issuing frequency adjustment: 163.266ppm
:Jun 16 16:36:24 ylem dntpd[73041]: issuing frequency adjustment: 658.908ppm
:Jun 16 18:43:20 ylem dntpd[73041]: issuing frequency adjustment: 548.854ppm
:Jun 16 19:15:08 ylem dntpd[73041]: issuing frequency adjustment: 524.173ppm
:Jun 16 21:22:10 ylem dntpd[73041]: issuing frequency adjustment: 164.604ppm

:Jun 18 15:19:28 test28 dntpd[611]: issuing frequency adjustment: -99.871ppm
:Jun 18 15:49:00 test28 dntpd[611]: issuing frequency adjustment: -107.887ppm
:Jun 18 16:11:40 test28 dntpd[611]: issuing frequency adjustment: -99.721ppm
:Jun 18 18:27:28 test28 dntpd[612]: issuing frequency adjustment: -104.664ppm
:Jun 17 02:04:02 test28 dntpd[611]: issuing frequency adjustment: -104.562ppm
:Jun 17 02:15:20 test28 dntpd[611]: issuing frequency adjustment: -105.193ppm
:Jun 17 02:23:51 test28 dntpd[611]: issuing frequency adjustment: -104.339ppm
:Jun 17 02:41:41 test28 dntpd[612]: issuing frequency adjustment: -90.960ppm
:Jun 17 03:36:29 test28 dntpd[611]: issuing frequency adjustment: -104.870ppm
:Jun 17 15:48:14 test28 dntpd[612]: issuing frequency adjustment: -106.046ppm
:Jun 16 18:11:07 test28 dntpd[611]: issuing frequency adjustment: -100.191ppm
:Jun 16 19:09:55 test28 dntpd[611]: issuing frequency adjustment: -116.056ppm
:Jun 16 19:58:46 test28 dntpd[611]: issuing frequency adjustment: -101.668ppm

    I'm going to do some work on dntpd to try to correct two unrelated
    issues.  First I'll try to have it detect a bad time source when 
    several are available.  Second, I'll have it re-run the DNS lookup
    if a server stops responding and I'll have it detect duplicate IPs.

					-Matt
					Matthew Dillon 
					<dillon at backplane.com>
					-Matt






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