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
  

• 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.