Recover Intel Matrix Raid Configuration

If you only have 3 hard drives, your options are:

• Two drives in a raid 1 mirror, plus one extra drive. You can use the extra drive for backup archives so that if you delete a file, you can restore it from the backup.
• Two drives in a raid 0 stripe, plus one extra drive - the raid 0 will have no redundancy, so that's a dangerous option.
• Three drives in a raid 0 stripe - no redundancy, so that's dangerous
• Three drives in a raid 5 stripe - redundancy, but not too fast in terms of writes

If you could go up to 4 drives, then you can have one big raid 10 (or 0+1 stripe) that will give you fast reads/writes, plus redundancy across the whole thing. That'll make the most sense from an ease-of-management perspective.

The wikipedia article on RAID levels is actually quite good:

http://en.wikipedia.org/wiki/Redundant_array_of_independent_disks

There is already a RAID level for what you want; it's called RAID 10.

The MTBF for professional and consumer level drives has increased by an order of magnitude in recent years, the uncorrectable error rate has stayed relatively constant. This rate is estimated at 10^14 bits, so one bit per 12 terabytes read, for consumer SATA drives, source.

So, for every scan of your passes of your 24Tb drive, statistically you will encounter at least 2 single bit errors. Each of those errors will trigger a RAID5 rebuild, and worse, during rebuild a second error will cause a double fault.