After all the discussion of configuring and managing storage in VMware vSphere 4 environments, these are the core principles:
Pick a storage architecture for your immediate and midterm scaling goals. Don't design for extreme growth scenarios. You can always use Storage VMotion to migrate up to larger arrays.
Consider using VMFS and NFS together; the combination provides a great deal of flexibility.
When sizing your initial array design for your entire vSphere environment, think about availability, performance (IOps, MBps, latency), and then capacity—always together and generally in that order.
The last point in the previous list cannot be overstated. People who are new to storage tend to think primarily ...