[jimmybgood9]

So I'm a cheapskate and a couple months ago I bought a used WD RE3 1TB drive. I'm perfectly happy with it even the rather noticeable seek noise. So I've noticed after writes of several GB are finished, while my monitor shows no disk activity, a low, steady seek noise for several seconds followed by quiet for a couple seconds with this noise sequence repeating for up to a few minutes for very large writes (> 100GB).

What the heck is this drive doing?