How can I create a Virtual Hard Drive from a physical linux server?

I am looking into virtualizing my current linux servers to run as guest operating systems on a Windows Server 2008 system using Hyper-V.

I currently have a fileserver running Debian Etch and a mail server running Red Hat 8.0 and have not been able to find an easy way of converting the physical machines into Hyper-V VHDs.
If anyone has done this before or has any ideas on how I can do this it would be greatly appreciated.

Thanks in advance.