I bought HGST 4TB drives (HDN726040ALE614) a couple of years ago and put them in a NAS. Just pulled the drives after around 5 years of not using it and now they are all giving me this sound. It spins up, makes a rhythmic noise that's akin to the normal read/write sound (not clicking), then spins down, so I can't detect it on a computer to check SMART. Any advice? They were barely used before I stopped using the NAS.
Sound: Link
