virt-install
--virt-type=kvm
--name centos7
--ram 2048
--vcpus=1
--os-variant=centos7.0
--cdrom=/root/CentOS-7-x86_64-Minimal-2009.iso
--network=bridge=br0,model=virtio
--graphics vnc
--disk path=/var/lib/libvirt/images/centos7.qcow2,size=10,bus=virtio,format=qcow2