My experience with SANs is that they are anything but consistent. Local storage is a better idea: fewer moving pieces to go wrong, fewer moving pieces to understand and debug, fewer possible sources of contention, and the latency is low.

SANs in a cloud environment optimize for the wrong thing. Servers by and large have a high uptime -- since their falling over is comparatively rare, this is simply a problem I've never had difficulty with. What I have had in spades, before I learned better, were database problems due to wild fluctuations in latency to the SAN.

It doesn't help that when SANs kick the bucket, they tend to affect a lot of things.