Mike D’s Blog

There’s a good write-up of the University of Plymouths Exchange 2007 virtualization project. I just met with 2 customers this past week that both asked about virtualizing Exchange 2007. They both brought up the two biggest questions on Exchange virtualization: what about performance and will Microsoft support it. There’s good answers for both.

First on the performance side. The article has two good quotes here:

But James didn’t skimp on hardware resources. “I’ve seen people try and shoehorn huge applications on what is an underpowered server to start with, and then they say that virtualization didn’t work for them,” he said. “Virtualization is not some magic technology that makes it so you can get something out of nothing.”

To that end, each Exchange server in the University’s environments is assigned four virtual CPUs (vCPUs) and 16 GB of RAM to start, which can be “adjusted to find the sweet spot of what our performance really is,” James said. Ultimately, James’ goal is to achieve a 2:1 consolidation ratio on his high-utilization ESX nodes, but not at the expense of performance. “With high-utilization applications, do not overcommit resources; give them all the resources they require,” he said.

I couldn’t agree more with that statement. You should definitely give these larger apps the hardware they need. It’s not about high consolidation ratios or really consolidation at all when you go after larger workloads. It’s really about the benefits that you’re getting with virtualization – mobility, abstraction, and flexibility. These are all advantages virtual machines have over their physical counterparts. I’ve seen numerous customers now doing 1:1 consolidation ratios for strategic apps just so they can get the benefits of virtualization – mostly for easy DR. There’s also the possibility that the virtual system just might scale better and outpace the physical system as can be seen in the recent Exchange benchmarks.

As for support there’s good news on that front. On September 1, 2008, Microsoft officially launched the Server Virtualization Validation Program (SVVP). SVVP offers full support for Microsoft operating systems and applications that run on validated hypervisors. The good news is that VMware is certified under SVVP. The better news is that Exchange 2007 is supported under SVVP.

Overall, I think Chris Wolf from Burton group put it best when talking about the possibility of running large workloads:

Chris Wolf, an analyst at Midvale, Utah-based research firm Burton Group who specializes in virtualization, said he sees more and more organizations virtualizing high-performance production applications like Exchange, Oracle and high-I/O imaging servers. “Last year it was 25% of our clients; this year it’s more like 50% — you just need good hardware to do it.” Provided adequate resources, though, there are not a lot of barriers to virtualizing those applications today.”