We are right now in initial phase to setup a production server having PostgreSQL database installed and would require help with Disk configuration. The database size would grow approx to 500 GB. I have gone through the following link http://momjian.us/main/writings/pgsql/hw_performance/index.html which was very helpful. However what I would like to understand is, do you have any figures around minimum / optimal disk performance for postgresql to operate? As an example I remember MS have a document on Exchange that gives some rough guidance around the number of IOPS it needs depending on number of users / mailbox size.