If you talk to CIOs who really "get" virtualization, the benefit that excites them the most is not cost savings but agility. I'm talking about the ability to say yes, quickly, to a business side request. Virtualization is helping smart IT leaders morph from "no" people to "yes" people. That's a huge shift for many IT organizations and companies. But in order to be a yes person, you need to have enough carefully-managed virtual infrastructure on hand.

This is where virtualization management tools from the likes of Akorri and CiRBA, which released an updated version of its software this week, can earn their keep.

You're not thinking about virtualization capacity planning on an ongoing basis? Big mistake, says IDC research director Stephen Elliot, a good source on virtualization best practices. (IDC is a sister company to CXO Media.)

"Many IT organizations start with the idea that capacity planning is a one time project, when in fact it should be an ongoing discipline as virtualization usage proliferates, Elliot says. "Right now, most IT organizations use capacity planning through an initial services engagement, and not as an ongoing demand management technique. This will change over time for IT organizations that understand that virtualization is really about the application services, and the opportunity to increase IT agility."

Or as CiRBA CTO and co-founder Andrew Hiller put it to me last week, "After you virtualize an environment, you realize things come up every day." Some application changes and becomes a memory drain on the physical box. Some new process becomes a security problem. And so on. With the new CiRBA tool, Data Center Intelligence 5.0. the company has emphasized on-the-fly analytics that can be pushed via dashboard, alerting you to these blips on the virtual radar screen.

CiRBA's tool was already known for helping IT staff do detailed analysis on how to consolidate physical boxes into virtual machines, considering server configuration, business process and utility issues. The new version makes doing ongoing analysis of the virtual environment a priority. (The software also adds functionality that helps you do financial chargeback planning and power consumption analysis—two areas that will no doubt continue to increase in importance for IT.)

If you haven't seen the CiRBA tool, it will display a 3D model of your physical and virtual infrastructure, showing you what looks like a Rubik's cube of red "hotspots" that could pose trouble—a memory-hogging app; a database that shouldn't live on the same box as another app for security reasons, and so forth. (For a look at how one IT shop uses the technology, see our recent profile on how Underwriters Laboratories uses CiRBA's tools to plan virtualization moves. )