A disk image created with the dd command like this: dd if=/dev/sdx of=dskimg.raw bs=512

… can be converted directly into a VirtualBox VDI (“virtual disk image”) with:

VBoxManage convertdd dskimg.raw yourvmname-sda.vdi --format VDI

A raw disk image can also be converted to a KVM qcow2 image:

qemu-img convert -f raw -O qcow2 /path/to/your/hdd/vm01.img /path/to/your/hdd/vm01.qcow2

Links: Tech Info … Main