Thanks fatrandy13. It works, but i have some questions:
-Is this a "growing" image- ie does it grow by adding data? Or do i have to use a special program, in order to resize it?
-If i do: "dd if=/dev/hda (NOT HDA1) of=disk.img" and at the same time i use a backup partition (/dev/hda7 for example, mounted as /mnt/backup) to store the image, would that cause a problem and make the image grow recursively?