KVM

Сжать qcow2

qemu-img convert -O qcow2 /path_to_you_image/you_name_image.qcow2 /path_to_you_image/you_name_image.qcow2

Конвертировать из qcow2 в raw

qemu-img convert -f qcow2 -O raw /path_to_you_image/you_name_image6.qcow2 /path_to_you_image/you_name_image.raw