On Fri, May 1, 2009 at 3:01 PM, Leland Lucius <[email protected]> wrote:
> Actually, most of our servers do only have 1 single VCPU. I was just > concerned about a couple of Linux servers where we run 6 WAS instances > per server. Want to make sure that each instance got his turn at a VCPU. When you have the option: don't stick multiple applications in a single virtual machine. The critters compete with each other for resources and z/VM can't do anything about it. The smoke and mirrors of virtualization is much easier to manage when you do one thing in a virtual machine. That way z/VM can allocate the appropriate resources to the workload. This is also why it performs better when you have the different tiers of a multi-tier application in different virtual machines. The improvements through appropriate tuning of each virtual server more than make up for the extra cost of communication between the tiers. Rob PS Since nobody is listening anymore... Many people get it wrong when they define multiple virtual CPUs, in which case they get less resources rather than more. You may need to "help" them in picking the test scenario, but it sometimes helps to end the debate when stubborn people with big badges are involved ;-) -- Rob van der Heij Velocity Software http://www.velocitysoftware.com/ ---------------------------------------------------------------------- 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
