Its really fascinating to watch amazon re-learn/re-implement the lessons IBM baked into mainframes decades ago. Once you get out of shared-nothing/web-scripting land you realize that I/O is much more important and difficult than cpu. What amazon calls EBS IBM has been calling "DASD" forever. I wonder if there are any crossover lessons that they haven't taken advantage of because there just aren't any old ibm'ers working at amazon.
IBM's implementation of DASD on the mainframe was always implemented under the assumption that it was a secondary storage medium for data. Meaning, it wasn't accessed often, and it wasn't implemented for top performance.
Think of a bridge between high performance disk and tape.
