Convert VirtualBox VDI disks to KVM QCOW2 disks
There are two methods to achieve the conversion of virtualbox disks formats to KVM disk formats:
- Convert VDI to raw disk image (.img) and then convert the raw disk image to QCOW2.
- Directly convert VDI to QCOW2 using the qemu-img command.
Let us look at the first method of converting VirtualBox VDI first to a raw disk and later to KVM format.
Convert VirtualBox VDI to Raw Disk Image
In my local machine, I have installed Oracle 9 in VirtualBox and I have its virtual disk images stored in ~/VirtualBox VMs/Oracle8. I am changing into this directory and convert the Oracle 8.vdi image to raw image as below:
$ sudo vboxmanage clonemedium --format RAW Oracle-8.vdi Oracle8.img
0%...10%...20%...30%...40%...50%...60%...70%...80%...90%...100%
Clone medium created in format 'RAW'. UUID: 49451559-be0f-49d2-b804-41c62e266760
You should notice a ram image created.
$ ls
Oracle8.img
Note that /home/lorna/KVM/ is just a directory which I created to hold the converted images. Now we are going to convert .img to KVM format, qcow2, by executing the below command in the directory where the raw image is saved:
sudo qemu-img convert -f raw Oracle8.img -O qcow2 Oracle8.qcow2
You should notice two images in the directory.
$ ls
Oracle8.img Oracle8.qcow2
Convert VDI images directly to QCOW2
You can directly and simply convert a vdi image to qcow2 by running the below command:
sudo qemu-img convert -f vdi -O qcow2 vm-disk-name.vdi vm-disk-name.qcow2
Run a VM on KVM by importing an Image
To use the created Image to create a VM on KVM, open virt manager and click on the VM icon to create a new virtual machine. Choose Import Existing Disk Image and click Forward.

Next, browse to the location of the image then click Forward.

Specify CPU and RAM for your VM and click Forward.

Next, verify settings and click Finish.

Your VM will begin creating.
We have successfully learned how to convert VirtualBox disk images to KVM format. You may also need to check on how to install Virtualbox and KVM hypervisors. Click the links below: