We made a lot of snap decisions here. There are quite a few RAID levels that we simply ignored, so there should be some discussion regarding the reasoning we used.
Let's begin with RAID level 0. Level 0 stripes data across all disks at once. It's certainly convenient, but a single drive failure will lose all stored information in the array. What about RAID level 1? Level 1 acts as a full mirror of all data stored. For every set of drives, a second set of drives has an exact copy. If a drive fails in one set, the second set is still available. However, if that set also experiences any failure, all data is lost.
When we talk about RAID 1+0, we actually combine the mirroring capability of RAID 1 with the striping of RAID 0. How? ...
