Ubuntu edgy Xen 3.0.3 Linux 2.6.17-6 craches!! We will use Xen 3.0.4 Linux 2.6.16.33 from xensource.

The following HOWTO is based on XenOnUbuntuEdgy document but adapted for amd64 platform and has typos corrected.

Hypervisor and Dom0

1. Install network-bridge utils
   

   sudo apt-get install bridge-utils python-pam

2. If /lib/tls/ exists then to disable TLS  with XenLinux 2.6 kernel (see Xen user guide section 2.5.3). run
   

   sudo mv /lib/tls /lib/tls.disabled

3. Download Xen 3.0.4 tarball for AMD64 platform, unpack it and in dist directory run
   

   sh ./install.sh

4. Add the following section to /boot/grub/menu.lst
   

   title           XEN/2.6.16 (from XENSOURCE)
   root            (hd0,0)
   kernel          /xen-3.0.4-1.gz
   module          /vmlinuz-2.6.16.33-xen root=/dev/mapper/cens_vg-kev_root ro
   module          /linux-2.6.16.33-xen.initrd.img

5. Create initrd image:
   

   sudo mkinitramfs -o /boot/linux-2.6.16.33-xen.initrd.img 2.6.16.33-xen

6. Reboot using XEN/2.6.16 kernel.

7. Configure XEN by editing file /etc/xen/xend-config.sxp as follows
   

   
   (xend-unix-server yes)
   (network-script network-bridge) # using default network device
   # (network-script 'network-bridge netdev=eth1')
   (dom0-min-mem 3072) # Assuming 4G RAM, if 2 GM, set to 1024
   (dom0-cpus 0)
   (vncpasswd '')
   

8. Start Dom0:
   

   /etc/init.d/xend start
   

   When this works, create symbolic links to rc2.d
   

DomU

Create file systems and swap:

sudo mkfs -t ext3 /dev/cens_vg/cens_root
sudo mkfs -t ext3 /dev/cens_vg/cens_home
sudo mkswap  /dev/cens_vg/cens_swap

The idea is to rsync the current cens server to the above partitions and be done with setting up the new cens.
First, we rsync cens homes to /dev/cens_vg/cens_home partitions:

sudo mkdir /mnt/sda2 && sudo mount /dev/cens_vg/cens_home /mnt/sda2
sudo rsync -avz cens:/home/ /mnt/sda2 # enter first sudo pw and then cens root pw when asked
sudo umount /mnt/sda2

Execute (to fix hotblug setup failure)

ln -s -f /bin/sh /bin/bash

Test DomU fiasco

Let us check that XEN works in our hardware. For that we install edgy as follows

sudo mkdir /mnt/sda1 && sudo mount /dev/cens_vg/cens_root /mnt/sda1
sudo debootstrap edgy /mnt/sda1
sudo cp -a /lib/modules/2.6.16.33-xen/ /mnt/sda1/lib/modules
# fix apt/sources.list, network/interfaces, hostname, hosts files under /mnt/sda1/etc/

Create the following /mnt/sda1/etc/fstab file:

# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    defaults        0       0
/dev/sda1       /               ext3    defaults,errors=remount-ro 0       1
/dev/sda3       none            swap    sw              0       0

Create the following /mnt/sda1/etc/network/interfaces file:

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet static
        address 172.17.4.169
        netmask 255.255.0.0
        network 172.17.0.0
        broadcast 172.17.255.255
        gateway 172.17.0.1
        # dns-* options are implemented by the resolvconf package, if installed
        dns-nameservers 172.17.0.10
        dns-search kybi

Fix hostname:

echo fiasco > /mnt/sda1/etc/hostname

When done, do unmount

sudo umount /mnt/sda1

To configure the DomU fiasco, create a file /etc/xen/edgy-fiasco.cfg containing

kernel = "/boot/vmlinuz-2.6.16.33-xen"
builder='linux'
memory = 512
name = "fiasco"
vcpus = 1
vif = [ 'bridge=xenbr0' ]
disk = [ 'phy:cens_vg/cens_root,sda1,w',
         'phy:cens_vg/cens_home,sda2,w',
         'phy:cens_vg/cens_swap,sda3,w']
root = "/dev/sda1 ro"
#extra =  "init=/bin/bash" # uncomment to set root password in the first boot

To run DomU fiasco with console login, run

xm create edgy-fiasco.cfg -c

Additional notes

1. When creating DomU cens when Dom0 has multiple network interfaces, check that cens sees only one of them.