If the 250GB of storage on your Series 3 TiVo isn’t enough – those HD recordings really suck up space – a guy on the Tivocommunity forums has devised a way to grow your puny storage to something your parents would be proud of.
A word of warning before taking this mod to town. You should be experienced in opening up your Tivo, or if not that, your own PC. You should also be somewhat comfortable running Linux commands to modify and partition your hard drives and have some knowledge of how RAID works. Other than that it’s pretty straightforward.