Oh, mirroring is also a safe way, but you lose more harddrive space that way. For every drive you mirror, you obviously need another drive to mirror it. That way, you are only ever using 50% of your available space.
With RAID5 you lose one drives worth of space, but in a five-disc array that is...
By "real RAID" I guess I was referring to a system where the RAID functions are handled in hardware, and are independent of the OS. The RAID subsystem also has built-in processing power so the system doesn't get bogged down with having to do the processing for the storage system.
Such cards do...
Not yet, but it's in the works. However, I'm planning on actual hardware RAID but with IDE drives; Adaptec has a RAID card with CPU assistance that allows you to create a "real" RAID array using RAID5 and there are other manufacturers as well.
Not the fastest way to access data, but impervious...