I tried to install  RHEL 6 VM:

virt-install --connect qemu:///system --name keptcarry-dl-vm1.host.com --ram 2048 --nographics --accelerate --vcpus 2 --noreboot --cdrom /var/cache/vm/iso/rhel-6.3.0_83-1.x86_64.iso --disk path=/var/cache/vm/vdisk/keptcarry-dl-vm1-201306080806.qcow2,size=100,cache=none --mac 00:50:56:35:c0:68 --network bridge:br0