Windows 7 Qcow2 File 【95% Limited】
Then, on the QEMU host, add discard=unmap to your drive options:
A QCOW2 file is a type of virtual disk image that stores the contents of a virtual machine's hard drive. It's a self-contained file that can be used to store the operating system, applications, and data of a virtual machine. QCOW2 files are similar to other virtual disk formats, such as VMDK (used by VMware) and VDI (used by VirtualBox). windows 7 qcow2 file