[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] Re: Reuse QEMU image for HVM?

  • To: "Jun Koi" <junkoi2004@xxxxxxxxx>
  • From: "Grant McWilliams" <grantmasterflash@xxxxxxxxx>
  • Date: Tue, 9 Dec 2008 00:29:28 -0800
  • Cc: xen-devel@xxxxxxxxxxxxxxxxxxx, Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
  • Delivery-date: Tue, 09 Dec 2008 00:29:57 -0800
  • Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:references; b=U49pT09edvCBowCWOadHiQX3Zg83Uq0qCOtVvwMQt+mLZUxHb5/knSugLKXNjqAnp5 zCnM56Nb9t0MoIvJfmxSsbRA/xnKrw8r+tU4T4E2B2vXlyzjh3qj8VQZ/dxYCK4ggeTF oc5NQqBj2ZvNw0SMYVD+uJf+IA/FMLCvqNfKE=
  • List-id: Xen developer discussion <xen-devel.lists.xensource.com>

On Mon, Dec 8, 2008 at 7:50 PM, Jun Koi <junkoi2004@xxxxxxxxx> wrote:
On Tue, Dec 9, 2008 at 1:34 AM, Grant McWilliams
<grantmasterflash@xxxxxxxxx> wrote:
>> It seems that the reason is qcow2 file created by QEMU tool is not
>> supported by Xen??
>> Thanks,
>> Jun
>> _______________________________________________
> From what I know this is true. It is probably the biggest blunder of the
> virtualization world! I'd like to
> know who at the xen team decided to adopt qcow but not make it compatible
> with QEMU. You can
> use qcow but you need to use xen's tool to create it. From what I understand
> there's a difference in
> endianness of the file.

Too sad if that is true. Could anybody confirm this?

I tried to see if that is true or not, by creating 2 images with
qemu-img (from QEMU) and qemu-img-xen (from Xen). The command is like

qemu-img create -f qcow2 img.test1 10MB
qemu-img-xen create -f qcow2 img.test2 10MB

And then I tried to diff these 2 files (diff img.test1 img.test2), but
the result was: 2 files are completely same.

So it doesnt seem right that qemu-img-xen does something difference
with qcow2 format. I tried to compare qcow format, too, and didnt see
any difference.

Any idea??

I googled it and the source I got it from said to use only qcow-create and img2qcow utilities and not to use qemu-img because of the incompatibilities. Later I saw posts on this mailing list outlining the endian difference between qemu qcow and xen qcow.

Here's a thread that I followed, it's as new as March 08...http://lists.xensource.com/archives/html/xen-devel/2008-03/msg00728.html

Grant McWilliams

Xen-devel mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.