6.7 Concluding Thoughts

The technology behind disk arrays helps us solve one of the most limiting factors in performance and reliability: the rotation of platters coated with magnetic film. It's a remarkably simple idea that lets us, if not kill, at least stun two birds with one stone. Unfortunately, there are a great many myths and falsehoods surrounding how to design a disk array for optimal performance in any given environment, and it's often difficult to determine what the environment in question is really doing.

If I can give you one concluding thought to take away from this chapter, it is that disk array design is largely a pattern of trial and error. Define a workload that you can measure reproducibly, time it, use the material in this chapter to start on the right path , and then experiment -- change one parameter at a time, repeat your benchmark, and find the best solution to your problem. This isn't an area where one size fits all.