Christian Messer was a virtualization skeptic not long ago. Now he swears by virtual servers.

"I was very skeptical. I think it's more mentality than anything else," says Messer, who is leading a server and storage virtualization project at G&J Pepsi Cola Bottling Company in Cincinnati. "It was more of a lack of understanding on my part. As I got it in a lab environment and began playing with it, my confidence level grew."

Messer, manager of information systems at G&J, explains that he had suffered numerous system crashes with Microsoft Exchange on physical servers and wasn't sure how it would perform on virtual ones. But the performance turned out to be fine, and virtualization has allowed Messer to drastically reduce disaster recovery times.

"I did a test employment with Exchange 2007 in a virtual machine environment and I got incredible results," he says. "Its performance was outstanding. I've got a much higher comfort level now with virtual machines than with physical servers. I'm able to leverage a lot more of my technology and get some ROI, which looks great to the accountants."

G&J is an independent bottler with more than 1,000 employees.

Before deploying virtualization last November, Messer had 78 servers, mostly from Dell and HP, and is in the process of consolidating them into just 16 Dell blade servers by the end of this year.

With VMware's hypervisor on quad-core servers, he's running two virtual machines on each core for a total of eight per physical server.

Sharepoint, Exchange, SQL and Oracle databases and file servers are all running on virtual machines. Before virtualization Messer was using less than 10 per cent of his server resources, and he still has room for improvement. He says he hasn't found an application that he wouldn't trust on a virtual machine.

"With each baby step, we were throwing more at [VMware] ESX," he says. "At this point I haven't thrown enough at it. I could probably double everything I've got on the ESX servers and still not be at 50 per cent utilization."

Messer is moving his storage from tape to a Dell EqualLogic iSCSI storage-area network and virtualizing both servers and storage. Having storage and server virtualization work together is key, Messer says, describing the ability to abstract logical storage from physical storage and easily reallocate storage units to virtual machines.

"In my opinion, it's necessary to have both if you want to get all the benefits," he says. "It makes your [disaster] recovery time quicker. The ability to grab snapshots of virtual machines, data volumes, replicate those and replicate changes. . . . Having multiple layers of redundancy scattered across your WAN, for me that's extremely valuable. I put more value on that than anything else."

It took about a half-hour to get back up and running after a SQL virtual server crashed recently. That's a huge improvement over the days when G&J had everything on tape.

"Just outside of five years ago, if you lost a server, you were rebuilding and reloading an operating system and grabbing all your data from tapes," he says. "Your downtime was a good solid eight to 10 hours."