You will need at least qemu-utils
# apt-get install qemu-utils
Check the qcow2 image
# qemu-img info apollo.qcow2 image: apollo.qcow2 file format: raw virtual size: 50G (53687091200 bytes) disk size: 50G
Convert the qcow2 image to vdi
# qemu-img convert -O vdi apollo.qcow2 apollo.vdi
convert qcow2 kvm images to vdi virtualbox images