I sometimes find bit-rot in some of my files. This is rare, but does happen. It annoys me that this is a) undetected for long periods of time and b) not fixable (except from backups), even with the standard mirrored RAID.
I'm now looking for a solution to this issue. In particular, I'm thinking of a three-way mirrored RAID, so that whenever the bit rot is caused by a drive, it's possible to know which drive and to replicate the data from the other drives. Additionally, I'd have a scheduled task running every week or so to read everything off all drives and make sure it's still in sync.
The Windows 7 software RAID doesn't support having more than 2 drives in a mirrored set up. What other options are there to do this?