Then add discard='unmap' to the disk XML. This shrinks the QCOW2 file when you delete files inside Windows 7.
Running Windows 7 on modern hardware isn't just possible—it can be excellent . By using the format with VirtIO drivers , host CPU passthrough , and regular maintenance compression , you get a VM that boots faster than native Windows 7 on old hardware, consumes less disk space, and offers enterprise-grade snapshot recovery. windows 7qcow2 best