qemu-img create -f qcow2 -o size=20G /data/sys/vps020_win2012r2_20g.qcow2
virsh destroy vps020
virsh undefine vps020
virt-install --os-variant list
sudo virt-install --name=vps020 --ram=1024 --vcpus=2 --boot=cdrom \
--os-type windows --os-variant win2k8 \
--disk path=/data/sys/vps020_win2012r2_8g.qcow2,device=disk,cache=writeback,format=qcow2,bus=virtio \
--cdrom=/data/iso2/9600.16384.WINBLUE_RTM.130821-1623_X64FRE_SERVER_EVAL_ZH-CN-IRM_SSS_X64FREE_ZH-CN_DV5.ISO \
--network network:default,model=virtio \
--vnc --vncport=59020 --vnclisten=0.0.0.0 \
--accelerate --hvm --noautoconsole
virsh detach-disk vps020 --target vda
virsh attach-disk vps020 /data/sys/vps020_win2012r2_20g.qcow2 vdb --subdriver qcow2 --cache writeback