[Fedora-xen] How to migrate a QEMU VM to Xen?

[Brian Lavender]

On Tue, Jun 05, 2007 at 10:56:00AM -0700, Brian Lavender wrote:
> On Mon, May 28, 2007 at 08:39:49AM -0400, Thomas Kocourek wrote:
> > I have been using QEMU for some time and the virtual machine works very
> > well. Is there a way to copy over the virtual machine from QEMU to XEN?
> 
> I was just thinking about this. Did anyone give details? Seems like you
> ought to be able to create a config file, put a Xen kernel in, and be
> good to go. I am about to try it, but I thought I would ask if you had
> success, so I could avoid the similar mistakes. 
> 
> apt-get install xen-linux-system-2.6.18-4-xen-686
> 
> Oops, I just used the Debian way. This is a Fedora list. Let's just
> pretend you want a Debian image then.
> 
> yum install kernel-xen.i686
> 
> and then create a config file for the image, similar to this howto.
> 
> http://wiki.rpath.com/wiki/Xen_DomU_Guide
> 
> I'll give it a shot and see if it works!

I created the machine using QEMU using a raw file system and it booted in
Xen, but I am not getting networking to come up. I don't see a networking
device. How do I get networking to appear?

 [root at localhost xen]# xm create -c debian 
 Using config file "./debian".
 WARNING:root:Unknown image directive savedefault
 WARNING:root:Unknown image directive savedefault
 WARNING:root:Unknown image directive savedefault
 Going to boot Debian GNU/Linux, kernel 2.6.18-4-xen-686
   kernel: /boot/vmlinuz-2.6.18-4-xen-686
     initrd: /boot/initrd.img-2.6.18-4-xen-686
     Started domain debian
     Linux version 2.6.18-4-xen-686 (Debian 2.6.18.dfsg.1-12etch2)
     (dannf at debian.org) (gcc version 4.1.2 20061115 (prerelease) (Debian
     4.1.1-21)) #1 SMP Thu May 10 03:24:35 UTC 2007

After my Debian VM boots, I get this kernel message.

debian:/lib/modules/2.6.18-4-xen-686# dmesg | grep eth
netfront: Initialising virtual ethernet driver.
netfront: device eth0 has flipping receive path.

Here is my xen config file
{{{
# Automatically generated xen config file
name = "debian"
memory = "512"
disk = [ 'tap:aio:/var/lib/xen/images/debian2.img,hda,w', ]
vif = [ 'mac=00:16:3e:5c:87:5f, bridge=xenbr0', ]

uuid = "fc23be35-40d8-4fc4-8708-5f6ffb3f5e66"

bootloader="/usr/bin/pygrub"
vcpus=1
on_reboot   = 'restart'
on_crash    = 'restart'
}}}

And the process I used to build the image using QEMU.
{{{
qemu-img create -f raw debian.img 5G
qemu -cdrom ../../iso/debian-40r0-i386-netinst.iso -hda debian.img -m
256 -boot d
qemu  -hda debian.img -m 384
}}}


-- 
Brian Lavender
http://www.brie.com/brian/