Just few steps for installation.
1. Create a 10Gb empty file with at /home/xen_image (change either size and location to fit your needs):
dd if=/dev/zero of=/home/xen_image bs=1M count=10240
2. We are installing Ubuntu 12.10 i386, actually you can install any other version of Ubuntu, you just need to download appropriate initrd.gz vmlinuz xm-debian.cfg, just browse folders from the link below:
http://nl.archive.ubuntu.com/ubuntu/dists/quantal/main/installer-i386/current/images/netboot-xen/netboot/xen/
For example Ubuntu 12.04 has codename precise, so installtion files for x64 version are in http://nl.archive.ubuntu.com/ubuntu/dists/precise/main/installer-amd64/current/images/netboot-xen/netboot/xen/
ok, now we need to download 3 files:
wget http://nl.archive.ubuntu.com/ubuntu/dists/quantal/main/installer-i386/current/images/netboot-xen/netboot/xen/initrd.gz
wget http://nl.archive.ubuntu.com/ubuntu/dists/quantal/main/installer-i386/current/images/netboot-xen/netboot/xen/vmlinuz
wget http://nl.archive.ubuntu.com/ubuntu/dists/quantal/main/installer-i386/current/images/netboot-xen/netboot/xen/xm-debian.cfg
Note: you should be in /
3. Edit xm-debian.cfg file and modify memory name vcpus vif disk
Note: recommended value for vif : vif = [”, ‘bridge=xenbr1’]