Peter,
Seems like we have not been talking about the same thing. Rainer asked if he could install an internal 1 TB drive in his ROCK based system with music on it and use it. I might have misread your posts but it looks like you twice said he could and not lose his files. Your last post indicates you think he is going to connect his 1 TB drive via USB which is not what he asked about. Also, your statement that ROCK is pretty tolerant of format for drives that don’t contain the OS itself only applies to USB connected drives, not to an internal drive.
See this post ( Technique for faster copies to internal storage ) from Danny.
Tim