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Re: [Xen-users] Xen guests clock is exactly 2 hours before dom0 time

To: Ralf Hornik Mailings <ralf@xxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-users] Xen guests clock is exactly 2 hours before dom0 time
From: John Haxby <john.haxby@xxxxxxxxxx>
Date: Fri, 11 Jul 2008 13:40:46 +0100
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Ralf Hornik Mailings wrote:
Dom0 uses ntp for time syncronisation. I set the time on my guests manually but after reboot any machine (Windows server, XP, Freebsd, even PV Machines like ubuntu) all run local time - 2 hours.

/proc/sys/xen/independent_wallclock is set to 0 so actually the time should be set by dom0...(?)

Any ideas, what this could be?

I would guess that you've got the system clock set to +0200 instead of UTC. Traditionally, unix has run with the system clock at UTC and all timestamps and so on are seconds since the 1st January 1970, 00:00:00 UTC. These days it's quite possible to set the system time (the real time clock) to something other than UTC and the system start-up looks after making sure the kernel's time is UTC.

Somewhere along the lines, I think this has broken down with your machine. It looks as though system time is actually +0200 in dom0. I'd start by looking closely at the output of date in dom0 -- is it CEST?


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