time skew
hi group,
I'm having this problem on my iMac.
it's a 500/in/64(upgraded to 576)/20(replaced with 80)/cd/ultra/56k/fw/vga.
since some time it jumps random amounts of seconds, mostly into the
future, this is not related to ntp (I disactivated it) nor to ntpdate (I
checked what would happen if I don't correct anything and I needed to
back up by 15 minutes after a few hours).
in my root crontab I run ntpdate every single minute, printing the
output in a logfile.
these are two excerpts.
the first one is funny, because I have twice very similar jumps into the
future, followed by a jump back by almost the same amount (ntpdate needs
to correct backwards twice and forward once). I attribute the
difference in decimals to real noise in the internal clock.
29 May 10:46:11 ntpdate[25265]: step time server 195.83.66.158 offset -167.980764 sec
29 May 10:43:23 ntpdate[25275]: step time server 75.13.24.211 offset -167.974535 sec
29 May 10:46:18 ntpdate[25283]: step time server 75.13.24.211 offset 167.980391 sec
29 May 10:52:07 ntpdate[25322]: step time server 75.13.24.211 offset -157.952154 sec
29 May 10:49:31 ntpdate[25338]: step time server 75.13.24.211 offset -157.953025 sec
29 May 10:52:15 ntpdate[25356]: step time server 75.13.24.211 offset 157.953061 sec
29 May 11:14:06 ntpdate[26499]: step time server 75.13.24.211 offset -57.821288 sec
29 May 11:13:11 ntpdate[26515]: step time server 75.13.24.211 offset -57.820978 sec
29 May 11:14:15 ntpdate[26523]: step time server 75.13.24.211 offset 57.820636 sec
all positive corrections appear in this kind of sequence, iow: there are
no isolated positive corrections.
but there are lots of isolated negative corrections, this is the log for
2007-06-01 00:00/02:00 (chosen for no particular reason).
1 Jun 00:01:55 ntpdate[32337]: step time server 200.43.64.77 offset -9.935709 sec
1 Jun 00:05:02 ntpdate[917]: step time server 200.43.64.77 offset -3.971027 sec
1 Jun 00:05:26 ntpdate[930]: step time server 200.43.64.77 offset -118.012014 sec
1 Jun 00:09:37 ntpdate[978]: step time server 200.43.64.77 offset -93.989084 sec
1 Jun 00:11:05 ntpdate[1013]: step time server 200.43.64.77 offset -82.005425 sec
1 Jun 00:09:48 ntpdate[1027]: step time server 200.43.64.77 offset -82.005035 sec
1 Jun 00:11:15 ntpdate[1040]: step time server 200.43.64.77 offset 82.005701 sec
1 Jun 00:12:21 ntpdate[1058]: step time server 200.43.64.77 offset -97.981546 sec
1 Jun 00:48:42 ntpdate[1337]: step time server 217.114.97.97 offset -53.934183 sec
1 Jun 00:57:53 ntpdate[1398]: step time server 217.114.97.97 offset -138.012260 sec
1 Jun 00:59:58 ntpdate[1429]: step time server 217.114.97.97 offset -45.952144 sec
1 Jun 01:01:11 ntpdate[1457]: step time server 217.114.97.97 offset -99.981401 sec
1 Jun 01:06:04 ntpdate[3420]: step time server 213.215.33.210 offset -50.048028 sec
1 Jun 01:07:37 ntpdate[3449]: step time server 213.246.63.72 offset -79.983239 sec
1 Jun 01:26:12 ntpdate[3586]: step time server 209.132.176.4 offset -90.010730 sec
1 Jun 01:44:53 ntpdate[3718]: step time server 209.132.176.4 offset -83.972177 sec
1 Jun 01:46:29 ntpdate[3750]: step time server 209.132.176.4 offset -75.929826 sec
1 Jun 01:50:55 ntpdate[3789]: step time server 209.132.176.4 offset -77.988682 sec
1 Jun 01:55:09 ntpdate[3836]: step time server 209.132.176.4 offset -91.970655 sec
any hints?
this is driving me nuts!
Mario
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