Some useful command to help running and setup qemu…

  • Create an empty compressed 10 Go disk image (in qcow2 format):

    $ qemu-img create -f qcow2 /home/kevin/qemu-disk-image.qcow 10G
  • Boot on your machine’s CD-Rom in qemu with previous disk image as primary HDD:

    $ qemu -cdrom /dev/cdrom -hda /home/kevin/qemu-disk-image.qcow -boot d
  • Same as above but with a CD-Rom iso image:

    $ qemu -cdrom /home/kevin/ubuntu.iso -hda /home/kevin/qemu-disk-image.qcow -boot d
  • Boot the previously created disk image:

    $ qemu /home/kevin/qemu-disk-image.qcow
  • Convert qcow image to a raw image:

    $ qemu-img convert /home/kevin/qemu-disk-image.qcow -O raw /home/kevin/qemu-disk-image.raw
  • Convert raw image to a qcow image:

    $ qemu-img convert -f raw qemu-disk-image.raw -O qcow2 qemu-disk-image.qcow
  • Mount a RAW disk image:

    $ mount -o loop,offset=32256 /home/kevin/qemu-disk-image.raw /media/qemu/
  • Mount a qcow2 disk image via the nbd protocol (don’t forget to install the nbd-client package):

    $ modprobe nbd max_part=63
    $ qemu-nbd -c /dev/nbd0 /home/kevin/qemu-disk-image.qcow2
    $ mount /dev/nbd0p1 /media/qemu
  • To run a x86_64 guest system on a 32-bit host, simply use qemu-system-x86_64 binary command instead of qemu.