I just finished putting in a 2TB drive for mr. desktop computer, it seems not that long ago I was shuffling hard drives around between the old server and the desktop. Most of today was spent moving data from one drive to another (at least, that's what the compy was doing... I was watching K-State lose). In the end, I moved about 1TB of data around. After some consideration, I opted to keep all of the "system" stuff on the smaller, older 1TB drive. The motivating factor for this was the generally poor reliability of 2TB drives. For the time being I'm making darn sure everything of importance is backed up.