Mixed virtual environments catching on

Mixed virtual environments are growing in popularity, but be careful: Managing a heterogeneous virtual server environment can be a challenge.

By Alex Barrett, News Director

In virtual environments, the question of VMware or Microsoft Hyper-V is usually posed as an either/or proposition. But for a growing number of IT departments, things aren't so black and white. For better or worse, an increasing number of IT managers run a mixed virtual server environment that includes VMware and Hyper-V.

Top virtual environments: Hyper-V and VMware
VMware and Hyper-V are the most popular virtualization platforms by a wide margin, according to the results of TechTarget's "Virtualization Decisions 2009 Purchasing Intentions Survey."

More than 72% of respondents said VMware is their primary virtualization platform, with Microsoft netting nearly 15%. No other vendor got more than 2%.

Respondents also weighed in on the idea of mixed virtual environments. Nearly 56% said they would prefer to standardize on one platform, and less than 2% said they would prefer to have a heterogeneous environment. But most said they would be open to a mixed virtual server environment if it helped them meet a specific need.
The reasons for a heterogeneous environment are, well, heterogeneous. Some shops are in transition, moving their virtual environments from VMware to Hyper-V. Others choose to segment their servers according to geography or department. Still others pick their virtualization platform according to the underlying physical platform or application.

When it comes to heterogenous virtualization, organizations often "won't even know they're doing it," said Andi Mann, the research vice president at Enterprise Management Associates. But the issue of mixed virtual environments is coming to the forefront these days, as Microsoft positions Hyper-V R2 as a viable alternative to VMware vSphere.

"There's certainly a lot more swap-out migration activity now that Hyper-V has IT's blessing," Mann said. "And there's a movement toward re-evaluating VMware."

VMware to Hyper-V in virtual environments
For some IT shops, running multiple virtualization platforms is a temporary situation, as the organization transitions from one platform to the other.

OSIsoft LLC, a San Leandro, Calif.-based real-time software vendor, is moving its back-office servers from VMware ESX to Microsoft Hyper-V because of cost.

As new systems come online, Barry Barnett, the senior systems engineer at the firm, adds them to his Hyper-V environment. At the same time, he is in no hurry to migrate VMware workloads, because he has several years of VMware maintenance left. The result: a heterogeneous environment for the time being.

Standardized virtual environments preferred
Data center expert Bill Claybrook takes a look at whether or not mixed virtual environments are a good idea in this article.

Each virtualization platform has its own management tools and licensing considerations, so the more you have, the more complex your virtual server environment will get. That can be a significant drawback if you're thinking about moving to a heterogeneous environment.

But certain virtualization platforms are better suited for certain purposes, such as cloud computing or desktop virtualization. And in those cases, a mixed virtual server environment may not be such a bad idea after all.
Managing the mixed virtual server environment poses no particular challenge, Barnett said. For virtualization management tasks such as initiating a live migration or VMware VMotion, Barnett uses Microsoft's System Center Virtual Machine Manager (SCVMM) to control both environments. If he needs to drill down into a VMware environment, he simply fires up the VMware vCenter client.

These days, "being heterogeneous is not an issue," Barnett said. "Back in the seventies and eighties, if you had a mixed-mainframe environment, vendors would point fingers at one another, but I haven't seen that in the x86 world."

Heterogeneous environment status quo
For many, running both VMware and Hyper-V could be a reality for years to come.

Joyce Meyer Ministries, an evangelical Christian church, runs VMware on its U.S. servers and a mix of Microsoft Virtual Server 2005 and Hyper-V in its 15 foreign offices.

Two years ago, as the ministry ran up against space constraints in its St. Louis, Mo., data center, it began virtualizing. A Microsoft shop, it considered Hyper-V at the time but believed that the hypervisor lacked the necessary features, and the church didn't have the in-house technical expertise to set up Hyper-V. So it chose VMware for its U.S. virtual environments, said Jonathan Smith, the church's technology infrastructure manager.

"The cost difference between Hyper-V and VMware is a night-and-day difference," Smith said. "But given the importance of the data, we figured the cost was justified."

The ministry runs some 110 virtual machines (VMs) on four Dell R905 hosts in its virtual server environment and hopes to add a few more to virtualize its remaining 60 physical servers.

Are mixed virtual environments possible?
Take a trip back in time to see what people were saying about mixed virtual environments
Some of the big issues in today's market, such as the emergence of Hyper-V and the cost of VMware's products, were just bubbling to the surface back then. But as the time has passed, it's clear that those are two of the main drivers of mixed virtual environments today.
Meanwhile, its foreign offices are migrating from Microsoft Virtual Server 2005 R2 to Hyper-V. Most of these offices have a couple of Dell 2900 servers running 10 to 15 VMs apiece. Smith and his team use a combination of SCVMM and System Center Operations Manager to manage foreign offices' virtual environments.

The ministry's plan is to stay on VMware for the three years remaining on its maintenance contract and then re-evaluate Hyper-V and VMware, Smith said.

"We're very conscious of any spending that we do," Smith said. "But at the same time, Doug and Joyce [Meyer] understand the value of having something solid and having something up."

While the ministry may switch from VMware to Hyper-V in three years' time, "maybe VMware will have changed their model and made it more competitive," Smith said.

Mixed virtual environments tougher to manage
EMA's Mann said that just because IT managers can run multiple platforms in their virtual environments doesn't mean they should.

"I don't like to see heterogeneity in any IT environment, because it makes the environment more difficult to manage," he said.

Each platform requires different skill sets, and there aren't many tools that support all the major platforms -- although they are coming, he added.

"It's organic," he said. "This is what happens when things are free; they get in."

Let us know what you think about the story; email Alex Barrett, News Director at [email protected], or follow @aebarrett on twitter.

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