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Re: [Xen-users] Resolve "Time went backwards" problem by using jiffies

On Mon, Jan 4, 2010 at 4:06 AM, Matthew Law <matt@xxxxxxxxxxxxxxxxxx> wrote:
Hi Daniel,

I'm sure someone has the answer - just not likely to arrive to quickly at
this time of year and a weekend ;-)

I ran in to this too (I'm a relative Xen newbie) and my experience of this
bug is that it is a problem which is inherent in the xenified debian
kernels.  They appear to use some of the backports from opensuse and there
appears to be an issue with the way they have been used in debian which
means the kernel clock sync doesn't work properly.

You can detach the clock sync from the dom0 and do it in the domU with ntp
(as per the debain wiki doc) or, build your own kernel using the vanilla
xen kernel sources (which works, but is a pain).  I opted for the former.
I get the impression that this won't be fixed for a while in debian stable
as, like so many others, they are concentrating on kvm over xen.

There may be other options.  I am sure others will chime in if there are.

Good luck,


Thanks for your prompt but detail reply! True true.. still in the new year mood..

Your reply totally concurs with Pasi's and they make sense now.

As a side question - which distro concentrates on Xen more? (if there is one)

Fedora Core is out of the question now, Ubuntu 9.10 installation is a pain for some reason,
I thought Debian would be the next best choice - now hearing what you guys said,
I'm wondering  if there is a better option (In the sense that I can rely on the built-in
xen package without touching the kernel myself).


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