https://unixblogger.com/2016/06/13/convert-img-raw-to-qcow2/
qemu-img convert -f raw -O qcow2 cirros-0.4.0-x86_64-disk.img cirros-0.4.0-x86_64-disk.qcow2
https://unixblogger.com/2016/06/13/convert-img-raw-to-qcow2/
qemu-img convert -f raw -O qcow2 cirros-0.4.0-x86_64-disk.img cirros-0.4.0-x86_64-disk.qcow2