I've got an Ultra 2 here that's only a few days old. In it is a Seagate Barracuda Green 2TB drive.
The drive is "ticking", every half second, even though the disk isn't doing anything. In fact, the ticking stops when I get disk activity. I just started noticing this recently, and am unsure if it was there all the time or if it just started today. I did a factory reset (running 4.2.21) just to be sure I didn't break anything, and still the same.
Any idea what is causing this?