Comment RAID 5? (Score 3, Insightful) 158
They wanted performance and went *RAID 5*? That pretty much sums the entire approach up. Let's not optimise the application first, the database second, but instead hide the problem by throwing hardware at it. Then what we'll do is use a RAID configuration that hobbles the write performance of the arrays and lets not mention what happens to performance when we lose a disk (don't say it won't happen).
Sure, RAID 5 is the answer to somethings, but not when the question is database *PERFORMANCE*.
Also - latency is more important than IOP/s. I don't care how many IOP/s you can do, if you're latency is high, the performance won't be. Most garden variety storage engineers don't seem to grasp this concept.