Re: wrong kern.boottime

"Poul-Henning Kamp" wrote:


> In message <075c01c3ebea$178b36e0$7890a8c0_at_dyndns.org>, "Cyrille Lefevre"
write
> s:
>
> >> >ntpd is running, so, I'm on time.
> >>
> >> Hmm, I'm not sure where last gets it's number from, maybe from utmp.
> >
> >no, from wtmp.
> >
> >> If the utmp record is written on boot before ntpd corrects the clock
> >> that would be one explanation...
> >>
> >> Either way, I'm pretty sure that kern.boottime contains what it should
> >> contain:  Our best estimate of the time when the system was booted.
> >
> >absolutely not, the real boot time was the wtmp time which is the same
> >as /var/run/dmesg.boot.
> >
> >a proof of the real boot time :
> >
> ># bzgrep Accounting /var/log/messages.*
> >messages.2.bz2:Feb  1 21:40:43 <kern.notice> gits kernel: Accounting enabled
>
> This is only a proof if the machine was NTPD'synced at this time.
>
> If your CMOS clock was a couple of days off, your system would boot with
> that time, and not until NTPD gets its act together would the clock
> be stepped to the right time.
>
> This is still the best theory I can come up with.
>

from /var/log/ntplog, there have been only a correction of less than 2 secs :

Feb  1 21:40:43 <ntp.notice> gits ntpdate[9394]: step time server 138.195.130.71
offset 1.880536 sec
Feb  1 21:40:47 <ntp.notice> gits ntpd[57196]: ntpd 4.1.1b-a Fri Jan 30 19:17:34
CET 2004 (1)
Feb  1 21:40:47 <ntp.notice> gits ntpd[57196]: kernel time discipline status
2040
Feb  1 21:55:00 <ntp.notice> gits ntpd[57196]: time set 0.125300 s
Feb  1 22:10:10 <ntp.notice> gits ntpd[57196]: time reset -0.202478 s
Feb  1 22:47:45 <ntp.notice> gits ntpd[57196]: time reset 0.276161 s
Feb  1 23:02:54 <ntp.notice> gits ntpd[57196]: time reset -0.156614 s
Feb  1 23:40:25 <ntp.notice> gits ntpd[57196]: time reset 0.834652 s
Feb  1 23:55:47 <ntp.notice> gits ntpd[57196]: time reset -0.531431 s

Cyrille Lefevre.
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