Mailing the story:
DOSBox Part 3: Installing DOS Onto A Virtual Hard Drive
The previous tutorial demonstrated the simplicity of booting from floppy images and creating other images using the tools provided by Linux. This guide continues on from that as it goes through step by step how to properly create a hard disk image, hook it up to DOSBox, and install whichever DOS you want, be it MS-DOS, PC-DOS, or DR-DOS.