QCOW2 stands for "QEMU Copy-On-Write version 2." Unlike the raw img format or VMware’s VMDK, QCOW2 offers three killer features:
: Standard Windows 8 installers do not include native drivers for high-performance QEMU hardware. You must typically load VirtIO drivers during the installation process to recognize the virtual hard disk. windows 8 qcow2
Or using qemu-img :
When running as a virtual guest, the (QEMU Copy-On-Write) disk image format provides several practical advantages over standard "flat" formats like RAW. Key Features of QCOW2 for Windows 8 Thin Provisioning (Dynamic Growth) QCOW2 stands for "QEMU Copy-On-Write version 2