On 07/08/2014 01:19 PM, m.roth at 5-cent.us wrote: > And can you explain the difference between "cloud" and "time-sharing > on a mainframe" Sure. "Cloud" is much more dynamic, for better or for worse, than mainframes in ye olde days. Cloud takes advantage on smart clients, and, well, is a bit of a nebulous terms covering many things traditional servers do, but with more of an emphasis on dynamic load balancing. Ideally, if no one is using a server that server should not be running, as it is wasting power. The challenge is to get servers up with low latency. And when I say 'servers' that includes physical iron as well as fully virtualized hardware and more fluid virtual containers that just sortof act like a server. It's all about getting the necessary services to the client processes, regardless of whether the client is smart or dumb. And ideal application for cloud-based technology is renderfarms; transparent spinup and spindown of render machines, which often contain very power-hungry GPUs, saves lots of money. As much as it is going to rub sysadmins the wrong way (because the very comfortable and flexible SA hat is one I wear often it definitely rubs me a bit wrong), ideally the admin should spend time on setup and implementation more than operation; the operation of this dynamic spinup and spindown of resources, once set up by a competent admin, should be entirely user-driven and automated. Ye Olde Mainframes (not the more modern stuff, which *is* more cloud-oriented) never did this and required monstrous opex for personnel. Cloud is about reducing opex, pure and simple. Setup can be capex, and thus a separate budget (at least here, once again wearing the way too stiff CIO hat). Robert mentions security, and that is a very very true statement, and is where it is incumbent upon the admin who sets it up to be competent.