Thanks for taking a look, johnnie.black.
I don't have a spare disk on hand, I can order one and have it here in a couple days if I need to, but I was hoping to avoid the expense.
I just ordered a hot swap bay to install in my server so I can move my parity drives into the server itself (out of the NetApp shelf), and I was going to see if doing this made any difference (as the drive in question is one of my parity drives).
I'll try the hot swap cage first and see if that seems to fix the issue, if not, then I'll grab another drive and replace it, but like I said, I was hoping to avoid that if possible.
I'll let you know what I find.