This command creates a new snapshot of the virtual disk. 3. : Use the qemu-img snapshot command to revert to a previous snapshot:

Which (e.g., Proxmox, Virt-Manager, VirtualBox) you plan to host the image on.

It allows you to create a read-only base image and spawn multiple linked virtual machines from it. Prerequisites

Over time, even after deleting files, the QCOW2 file may stay large. To shrink it:

If the standard QEMU Guest Agent MSI fails on Windows 7 SP1, use the legacy version from VirtIO 0.1.173, which works reliably. Alternatively, the community package provides a working solution using renamed DLL files.

This format natively supports snapshots, allowing you to save the state of your Windows 7 environment and revert to it if a configuration or virus breaks the system. VirtIO Drivers:

Mount the VirtIO ISO inside the running Windows 7 VM. Navigate to the guest-agent directory and run the appropriate installer ( qemu-ga-x86_64.msi for 64-bit Windows 7).