We are experimenting with that as well. So much for the five nines. We rarely have a problem with our mirrored drives. We're using Jamaica arrays on our private volumes, and a Nike array on our system volume. Of course, we made sure we had enough processing power and RAM to handle the overhead.
Performance is excellent.
When one of our mirrored drives does go down, it is a simple matter of calling HP to come in, swap the drive, and resync it. Granted, we're at risk until the failed drive is replaced. We had three instances of downed mirrors in 1998. Swapped online, not a problem. Our conscientious HP hardware support technician also took the time to check the firmware on these drives, as well as their controllers.