Use the qemu-img command to create the virtual disk. A 40GB to 50GB size is recommended for most use cases. qemu-img create -f qcow2 windows7.qcow2 40G Use code with caution. 2. Virtual Machine Installation
For the best performance, you should use during installation. Without these, Windows 7 may not "see" the virtual disk during setup because it lacks native drivers for high-speed virtualized hardware. Windows 7 KVM - Tom's Fabulous Web Page Windows 7 Qcow2
A QCOW2 file only takes up space on your host machine as data is actually written to it. For instance, a 50GB virtual drive might only consume 13GB of actual host storage after a fresh Windows 7 install. Use the qemu-img command to create the virtual disk