Virtualization may seem like a simple bolt-on technology for early adopters, but it will lead to a revolution in your infrastructure architecture, according to a Forrester Research analyst. But, of course, that's only if you know what you're doing.

Speaking to hundreds of IT professionals at this week's VMware Virtualization Forum 2008 in Canada, Forrester analyst Frank E. Gillett outlined his best practices on how to successfully plan and implement virtualization in an enterprise environment.

"The first thing you need to do is start with a business impact assessment of the applications you want to virtualize," he said. This involves considering how virtualization will affect the end-user's ability to work, as well as, the potential costs savings.

"Will you be able to defer purchases and will you be able to avoid expanding or moving your data centre?" he asked.

Often, IT managers will try to sell management on the environmental benefits that are possible with virtualization, but Gillett said emphasizing the hardware and infrastructure savings is a wiser move. The ability to provide better disaster recovery also ranked high on the list of reasons to virtualize, he said.

After the business impact stage, the next step for an enterprise is to ensure virtualization can deliver on its promises. Implementing model-based provisioning and evaluating the management tools used to automate both the physical and virtual environments are both crucial steps along this path, Gillett said.

"You need to be able to model the service behaviour of your virtual machines, predict server utilization, and work on performance isolation." If you know your Web site will need more capacity on the lunch hour, you need to be able to juggle your workload to make sure performance doesn't lag, Gillett said.

Srinivas Krishnamurti, director of developer product and marketing development at VMware, advised that IT managers consider its recently launched Distributed Resource Scheduler (DRS) to help them optimize server utilization.

"If there are just two VMs running on a particular box, DRS might allow you to move them elsewhere and take down the box altogether," he said.

One customer at the virtualization forum said the ability to stay on top of capacity requirements using VMware's Virtual Center plays a vital role in its virtual environment.

"The one application, one box, one business function approach is no longer there, but we still get the granularity through Virtual Center," David Grant, head of data centre management at Mitel Networks, said.

And unlike what many virtualization newbies might believe, the technology also extends to storage and networking, he said.

"You need to account for storage," Grant said. "It's something we're chewing over with all the new VMs were creating."

On managing those VMs, Gillett said many of today's systems management tools are still playing catch up to virtualization technology. "They assume servers and machines are always up," he said. "Most of these tools don't know how to patch and configure VMs that aren't running and assume offline machines have failed."