qemu-img create -f qcow2 -o cluster_size=2M win10.qcow2 80G

: Use the tablet input device ( -device usb-tablet ) in your QEMU command to keep the guest mouse cursor synced with your host.

qemu-img convert -f vmdk -O qcow2 -c windows10.vmdk windows10-compressed.qcow2

A generic QCOW2 image runs Windows 10, but you want it to fly . Here is the optimization checklist.

If your VM is taking up too much space even after deleting files, you can compact the image to reclaim space:

Appendices (optional)

qemu-img convert -f vmdk -O qcow2 source_disk.vmdk target_disk.qcow2 Use code with caution.

Start with a pre-made OSBoxes image to test, then build your own custom QCOW2 image from a Microsoft ISO for production use. Always keep a base image and use overlays for different projects.

You can save the "state" of your Windows 10 VM before making risky registry changes or installing updates. If something breaks, you can revert in seconds.