The drive is in a predictive failure state, it just has not dropped offline. Offlining the drive and then replacing it is the best option.
That's strange, as all drives report "Failure Predicted : No"
Now the controller is running a consistency check (that I can't abort). I have to wait to finish before offlining the drive.
I've also seen that both failed drives are on backplane 1:0. #4 was unable to read yesterday. Now even #5 (new drive) is unable to read some sectors.
Both drives are on backplaned 1:0
It is also possible that the PERC itself is failing and causing the issues. I would let the consistency check finish, replace drive 4, and if you still have issues after that, replace the PERC. You could also try turning off the cache on the PERC and see if that stops the read errors as a troubleshooting step.