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Re: [Xen-users] Xen 3.1 clock problems

I have this problem with PV domains as well.  I always get a "your clock sucks" answer, but I've never had a system this worked right on.

However, it is possible to change the time in a DomU.  You have to set a sysctl value.  From sysctl.conf on my systems:

# Allow NTP To Sync Xen Clock
xen.independent_wallclock = 1

I combine this with multicast NTP to make my Xen instances all sync to the Dom0s on my systems (which in turn sync to places more reliable).

On May 30, 2007, at 5:09 AM, Petersson, Mats wrote:

-----Original Message-----
Sent: 30 May 2007 12:53
Subject: [Xen-users] Xen 3.1 clock problems


In the past I've always assumed that if you got the time in 
dom0 right, 
then all the domu domains would have the correct time... something is 
broken in Xen 3.1 because now the domu time can be quite 
unrelated - and 
of course it's not possible to reset it back as you can't change the 
time in a domu...

This is causing havoc with kerberos.. it'll work fine for ages then 
suddenly one or other of the machines will stop authenticating.

goliath:/home/tmh# date -u
Wed May 30 11:46:45 UTC 2007

wolf359:/var/log/samba# date -u
Wed May 30 09:23:08 UTC 2007

Is this a HVM or PV domain? I believe in HVM, the clock isn't synced,
and you'll need to use a NTP server or similar to sync your time. 


I wonder if this is related to 'time is going backwards' that seem to 
scroll constantly up the console?  From reading around I'd got the 
impression that this error was normal.


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Jayson Vantuyl
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