There aren't a lot of easy answers for what filesystem to use or how to arrange your disks. It's better to err on the side of paranoia, not performance, if you expect to keep your database intact under the sort of odd things that will happen to it in production. And unfortunately, maximum reliability is usually slower too. The most valuable thing you can do is be systematic in how you test. Instrument what you're doing, benchmark whenever possible, and always try to collect reproducible examples of realistic workloads whenever they appear.