Is this anything to be concerned about?

Primary drive (OS installation, games etc) :

http://www.whitegiant.co.uk/misc/1hdd.JPG

Secondary drive (mp3s, pr0n, etc) :

http://www.whitegiant.co.uk/misc/1hdd.JPG

Can anyone explain what these mean? I havent really noticed a slowdown.

My drives seem a little louder than usual, they are coming on for about 3-4years old. I keep them regularly defragged (at least once a week), and Id hate to have to replace them.

I recently got very paranoid about my drives giving up so I have a brand new 320gig external I can transfer stuff to if needed.