Converting images from one format to another is generally straightforward. The qemu-img convert command can do conversion between multiple formats, including raw, qcow2, VDI (VirtualBox), VMDK (VMWare) and VHD (Hyper-V).

qemu-img format strings

Image format	Argument to qemu-img
raw	raw
qcow2	qcow2
VDI (VirtualBox)	vdi
VMDK (VMWare)	vmdk
VHD (Hyper-V)	vpc

This example will convert a raw image file named centos63.dsk to a qcow2 image file. $ qemu-img convert -f raw -O qcow2 centos64.dsk centos64.qcow2 To convert from vmdk to raw, you would do: $ qemu-img convert -f vmdk -O raw centos64.vmdk centos64.img The -f format flag is optional. If omitted, qemu-img will try to infer the image format. If you've created a VDI image using VirtualBox, you can convert it to raw format using the VBoxManage command-line tool that ships with VirtualBox. On Mac OS X, VirtualBox stores images by default in the ~/VirtualBox VMs/ directory. The following example creates a raw image in the current directory from a VirtualBox VDI image.$ VBoxManage clonehd ~/VirtualBox\ VMs/fedora18.vdi fedora18.img --format raw