Converting between image formats

Converting images from one format to another is generally straightforward.

qemu-img convert: raw, qcow2, qed, vdi, vmdk, vhd

The qemu-img convert command can do conversion between multiple formats, including qcow2, qed, raw, vdi, vhd, and vmdk.

qemu-img format strings

Image format

Argument to qemu-img

QCOW2 (KVM, Xen)






VDI (VirtualBox)


VHD (Hyper-V)


VMDK (VMware)


This example will convert a raw image file named image.img to a qcow2 image file.

$ qemu-img convert -f raw -O qcow2 image.img image.qcow2

Run the following command to convert a vmdk image file to a raw image file.

$ qemu-img convert -f vmdk -O raw image.vmdk image.img

Run the following command to convert a vmdk image file to a qcow2 image file.

$ qemu-img convert -f vmdk -O qcow2 image.vmdk image.qcow2


The -f format flag is optional. If omitted, qemu-img will try to infer the image format.

When converting an image file with Windows, ensure the virtio driver is installed. Otherwise, you will get a blue screen when launching the image due to lack of the virtio driver. Another option is to set the image properties as below when you update the image in the Image service to avoid this issue, but it will reduce virtual machine performance significantly.

$ openstack image set --property hw_disk_bus='ide' image_name_or_id

VBoxManage: VDI (VirtualBox) to raw

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, and Linux, 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/image.vdi image.img --format raw