Replacing the OS drive
The Xbox comes with either an 8 or 10GB hard drive. Although it is perfectly reasonable to install Linux on this hard drive, I chose instead to replace it with a 2.5" 6GB laptop drive since they are quieter and less power hungry. Note that you could also use a large Compact Flash card if you wished.
Replacing the hard drive is just like with a PC and to use a 2.5" drive you will need to buy an adapter cable and bracket. In the photo you can see the metal bracket that I used to put the 2.5" drive into the 3.5" drive bracket and the cable adapter that I used to convert the drive's 42 pin connector into the 40 pin connector required for regular IDE.