I've spent the last few days checking everything was working correctly, and it seems so. This is what happened Sunday:
Around 10 am local time, the database drive stalled once again, and I shut down the system, knowing I was going to correct things later.
Around 3 pm local time, I had moved everything to my work area, and wanted to start up to test everything would work fine when attempting to do the drive switch. But now the database drive box didn't start at all - no fan, no light, nothing. The other one seemed to start as usual. I thought it might be the power supply, so I switch to the other power supply - this time the box started, but I really didn't like the sound, so I turned it off quickly. The other box didn't like the power supply from the database drive box.
So, now I had two drives that I didn't know if I could even get working. Anyway, with two drives to switch and only two drives to replace them, I could wave goodbye to my RAID plans. The only hope I had was that it was the external boxes that were failing, not the hard drives themselves. And it turned out to be just that. So after I had copied the database drive successfully, I made the sites available again while copying the other drives - before moving things back where they belong.