I found these instructions that I will be trying later. Currently I'm letting DD duplicate the "bad" hdh drive to a good one, ignoring errors. I'll then try the instructions there to get the raid back to an operational state and run a reiserfs scan to see what files are bad.

What is a good non destructive way of scanning for errors when a system is in operation? I'd like to have the system do surface scans from time to time, since it seems the error on the thrid drive might have existed for some time. Only when I started a resync did it read the bad area and trip up.