Install Ubuntu VM

Initial KVM setup if this is the first VM:

virsh pool-define-as --name kvmpool --type dir --target /var/kvm/images
virsh pool-start kvmpool

Install a Ubuntu 14.04 VM direct from archive.ubuntu.com:

virt-install \
--name example \
--ram 4096 \
--disk path=/var/kvm/images/example.qcow2,size=24,format=qcow2 \
--vcpus=2,maxvcpus=6 \
--cpu host \
--os-type linux \
--os-variant ubuntutrusty \
--graphics none \
--console pty,target_type=serial \
--location 'http://uk.archive.ubuntu.com/ubuntu/dists/trusty/main/installer-amd64/' \
--extra-args 'console=ttyS0,115200n8 serial'