Why to have so many penguins? Linux is a multiuser multitask O/S, and works nice, so there is no need put every application to different O/S. 1 IFL: the processor speed is the mainframe's weekness so having more VM+kernel+... overhead is not a good idea.
On the other hand, one accidental slip of the finger in a combined services configuration and you take down multiple services. It's the principle of not putting all your eggs in one basket -- if there is no artificial scarcity of "hardware", there is no reason to combine services because you can actually deliver one server, one application at a reasonable cost point with acceptable performance, and you don't risk breaking other services accidentally. Yes, not screamingly fast, but reasonable, and how many applications *really* need 3 Ghz CPUs for anything but bragging rights? If your application *really* needs that kind of horsepower, you're on the wrong system anyway -- you need big Intel or PPC engines, not zSeries. Combined services models also increase the complexity of deployments and system management; it's very hard to control resource allocation between competing applications inside a single Linux system. It's trivial to balance workloads in separate virtual machines. Think about it: when's the last time you considered shared web hosting services for anything *really* business-critical? Why wouldn't you do that? Same reasons apply here. Some problems really *do* need big monolithic LPARs (although that's where I start to think that it's probably the wrong platform for the app unless it really is written to exploit zSeries hw features). Most don't, and managing LPARs is a LOT more expensive in people time than managing virtual machines under VM. Computer capacity is a lot less expensive than humans these days. I'll gladly buy more CPU resource if I don't have to buy more people. -- db ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
