Taking Xen guests (domU) alive via routed network

The xend config looks like this:

playground:~# grep -v ^# /etc/xen/xend-config.sxp
(network-script 'network-bridge netdev=dummy0')
(vif-script vif-bridge)
(dom0-min-mem 196)
(dom0-cpus 0)

Creating volume group for Xen domU (/dev/hdb2 was allready created with id 8e):

playground:~# pvcreate /dev/hdb2
  Physical volume "/dev/hdb2" successfully created
playground:~# vgcreate xen-vol /dev/hdb2
  Volume group "xen-vol" successfully created
playground:~# vgscan
  Reading all physical volumes.  This may take a while...
  Found volume group "xen-vol" using metadata type lvm2

Creating first domU:

playground:~# xen-create-image --ip 192.168.222.50 --hostname xetch.blubb.cyconet.org
General Infomation
--------------------
Hostname       :  xetch.blubb.cyconet.org
Distribution   :  etch
Fileystem Type :  ext3
Size Information
----------------
Image size     :  4Gb
Swap size      :  1024Mb
Image type     :  full
Memory size    :  128Mb
Kernel path    :  /boot/vmlinuz-2.6.18-4-xen-vserver-686
Initrd path    :  /boot/initrd.img-2.6.18-4-xen-vserver-686
Networking Information
----------------------
IP Address 1   : 192.168.222.50
Netmask        : 255.255.255.0
Gateway        : 192.168.222.1
Creating ext3 filesystem on /dev/xen-vol/xetch.blubb.cyconet.org-disk
Done
Installing your system with debootstrap mirror ftp://ftp.de.debian.org/debian/
Done
Running hooks
Done
No role script specified.  Skipping
Creating Xen configuration file
Done
Setting up root password
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
All done
Logfile produced at:
        /var/log/xen-tools/xetch.blubb.cyconet.org.log

Add the following to /etc/network/interfaces:

auto dummy0
iface dummy0 inet static
     address 192.168.222.1
     netmask 255.255.255.0
     network 192.168.222.0
     broadcast 192.168.222.255

Bringing up network interface, restarting xen and starting the domU:

playground:~# ifup dummy0
playground:~# /etc/init.d/xendomains stop
playground:~# /etc/init.d/xend restart
playground:~# /etc/init.d/xendomains start
playground:~# xm create xetch.blubb.cyconet.org.cfg -c
Using config file "/etc/xen/xetch.blubb.cyconet.org.cfg".
...

If you want to autostart your domUs, you have to symlink the configfile to /etc/xen/auto:

playground:~# mkdir /etc/xen/auto/
playground:~# ln -s /etc/xen/xetch.blubb.cyconet.org.cfg /etc/xen/auto/xetch.blubb.cyconet.org.cfg