>>> If it's Type 2, then four drives with a spare is equally tolerant. >>> Slightly better, even, if you take into account the reduced probability >>> of 2/5 of the drives failing compared to 2/6. >> >> Thank you very much for this info. I had no idea. Is there another >> label for these RAID types besides "Type 1" and "Type 2"? I can't >> find reference to those designations via Google. > > Nothing standard. RAID 10 pretty intuitively comes from RAID 1+0, which > can be read aloud to figure out what it means: "RAID 1, plus RAID 0," > i.e. you do RAID 1, then stripe (RAID 0) the result. > > The trick is that RAID 1 can refer to either mirroring (2-way) or > multi-mirroring (3-way) [1]. In the end, the designation is the same: > RAID 1. So if you stripe either of them, you wind up with RAID 10. In > other words, "RAID 10" doesn't tell you which one you're going to get. > > If I ever find a controller that will do multi-mirroring + RAID 0, I'll > let you know what they call it =)
Is multi-mirroring (3-disk RAID1) support without RAID0 common in hardware RAID cards? - Grant
