virt-install \
 --paravirt \
 --name=centos51u \
 --ram=800 \
 --vcpus=2 \
 --file=/var/lib/xen/images/centos51u.img \
 --file-size=20 \
 --file=/var/lib/xen/images/centos51u-swap.img \
 --file-size=2 \
 --nonsparse \
 --network=network:default \
 --network=bridge:xenbr0 \
 --vnc \
 --keymap=ja \
 --location=nfs:192.168.122.1:/var/export/cdrom