raw – The most simple file format and can be mounted locally
qcow2 – The most versatile file format supporting layered images, encryption, compression, and snapshots although there seems to be some performance issues
vdi – Virtualbox 1.1 compatible image format
vmdk – VMWare 3 and 4 compatible image format
vpc – VirtualPC compatible image format
Поэтому для конвертации в raw делаем следующее:
# qemu-img convert -f vpc -O raw something.vhd something.raw
