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Date:      Mon, 18 Sep 1995 05:35:45 -0700
From:      Poul-Henning Kamp <phk@critter.tfs.com>
To:        Bruce Evans <bde@zeta.org.au>
Cc:        freebsd-hackers@FreeBSD.org, mal@aristotle.algonet.se
Subject:   Re: xntpd (or kernel) timekeeping problem? 
Message-ID:  <6599.811427745@critter.tfs.com>
In-Reply-To: Your message of "Mon, 18 Sep 1995 22:10:26 %2B1000." <199509181210.WAA23027@godzilla.zeta.org.au> 

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> 11932 on your machine).  Calibration is hard to do since there is no
> generally available accurate clock.  ISA systems have another clock (the
> RTC) of unknown accuracy.  On my machines it seems to be more accurate
> and just as stable as the 8254 clock.

Actually I used xntpd to calibrate, I ran it, figured out that the drift
was terrible/untolerable, tweaked the kernel, waited a week, tweaked it
some more, waited a week, until my ntp had a nice avg drift of almost
zero over a week...  (notice that ntp may itself have a diurnal (or
other period) variance depending on your networks load, but over a
week, you will get the drift (pun intended) :-)

What we really need is a neat little utility you can run by hand, that
will run a ntpdate and figure out your drift since last you did that...

--
Poul-Henning Kamp           | phk@FreeBSD.ORG       FreeBSD Core-team.
http://www.freebsd.org/~phk | phk@login.dknet.dk    Private mailbox.
whois: [PHK]                | phk@ref.tfs.com       TRW Financial Systems, Inc.
Just that: dried leaves in boiling water ?



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