With server virtualization quickly growing ubiquitous in the enterprise, addressing the "Should I virtualize Exchange Server?" question seems inevitable for many IT managers. Answering "yes" was easy for Nicholas Merton, a member of the IT support staff at Maxol, an oil distributor in Dublin, Ireland.
Maxol's IT team had embraced server virtualization as a way to do more with less and had committed early to move as many applications as possible to a virtual environment. Email would not be an exception, said Merton.
This was two years ago when Maxol was running Microsoft Virtual Server 2005, which didn't support Exchange 2007. For that, the company would need to pick another virtualization platform. It decided on VMware, but later determined that sticking with a Microsoft product made more sense budget-wise. It signed on to become an early adopter of Windows Server 2008 with Hyper-V, added Merton. Its standalone hypervisor -- Hyper-V Server 2008 -- supports Exchange Server 2007.
Maxol is a small company with email volumes reaching a maximum of 2,000 messages weekly, Merton said. Its Exchange server supports about 70 users and about 150 mailboxes. Still, the Exchange server must be highly available, since Maxol's automated and Web-based online order-processing system generates invoices for delivery via email. "If we're without email, we'd suffer [a] loss of earnings," Merton noted.
High availability (HA) for the distributor's virtualized Exchange server is part of the clustering offered with Windows Server 2008. If a virtual machine fails, the cluster automatically moves the workload to another server.
To protect Exchange data, Maxol uses Microsoft System Center Data Protection Manager (DPM) 2007, which provides snapshots throughout the day. The company runs disk-to-disk-to-tape backups on site and backs up to disk at a remote site overnight. "If this site went down, Exchange would be down for no more than two to three minutes," Merton said.
Maxol's small size and HA needs make the company a perfect fit for a virtual Exchange scenario. According to Astrid McClean, Microsoft senior technical product manager for Exchange, virtualizing Exchange also works well for remote offices that need highly available servers or have disaster recovery needs.
Some companies can also benefit from improved server performance, noted Merton. "Exchange tends to take what you give it. It'll absorb anything. So if you run on a quad processor, it'll take every bit of that processing power," he added. "In the virtual world, we've been able to throttle down to our requirements so the machine isn't running a million miles an hour even though it's only processing a few email [messages] ."
Weigh Exchange virtualization pros and cons
Not all companies will consider virtualizing Exchange as readily as Maxol did. They may not experience the same noteworthy performance gains either. "There are situations where IT managers need to consider whether the benefits outweigh the complications of virtualizing Exchange," McClean said, describing a scenario in which a large Exchange server in an HA configuration is making full use of the hardware it's running on. "Adding virtualization might not provide enough benefits to warrant the work required," McClean said.
McClean cautions that deciding whether or not to virtualize Exchange means taking a hard look at the sizing and capacity of servers, and making sure those flow across into a virtualized environment. It also involves figuring out how you'd monitor and back up the system and manage HA. "These are keys to getting a virtualized Exchange environment working well."
At Maxol, switching Exchange from the physical to the virtual world has been a non-issue, Merton said. "We created a new server, migrated users, switched off the old server -- and it worked."
Beth Schultz is a freelance writer based in Chicago.