Over the past year, server virtualization has become a new data centre technology du jour. Microsoft, competing head-on with VMware, has its Virtual Server 2005 (which will soon even support Linux). Meanwhile a host of startups are putting novel spins on the technology. For example, SWsoft offers a tool that creates multiple instances of an operating system from one installed operating system; Meiosys and Trigence virtualize applications; and Virtual Iron Software performs virtual symmetric multiprocessing.
Network executives can stay savvy by following these four suggestions:
1. Keep your eye on the prize. As with any IT project, the best way to begin with server virtualization is to have a clear idea of the goal.
“The key is to think about what benefit it provides or what the company is trying to achieve,” says Scott Donahue, an analyst at Tier1 Research.
Be specific. Lofty results such as saving money or easing management headaches won’t help you choose the proliferating server virtualization option that is right for you.
“When you understand what you’re trying to do and what your deployment scenario looks like, then it’s easier to start differentiating between VMware and SWsoft or Microsoft, or between Meiosys and Trigence,” Donahue says. “But if you’re just thinking, ‘Well, I need to virtualize my environment, and I really like the idea of consolidation and cost savings,’ it’s going to be difficult. The different kinds of virtualization solutions are going to give you those high-level benefits. They’re all designed to do that.”
The trouble with being unclear about your ultimate goal is that you won’t get fine-tuned benefits, Donahue says. “You’ll get 40 per cent, but you might not get that other 60 per cent,” he says.
“Do your due diligence,” says Barry Lalone, server platform architect at Jack Henry & Associates, a technology provider for the financial industry.
Lalone reviewed a number of virtualization technologies, including VMware, Microsoft Virtual Server and User Mode Linux, before deciding SWsoft’s Virtuozzo was the best fit for the Lenexa, Kan., service provider’s Windows environment.
2. Start small. Once you’ve got a good grasp on your endgame, bring in the technology bit by bit.
When National Semiconductor decided to adopt VMware last year to boost abysmal utilization rates on its Windows servers, the IT staff took things slowly — despite being no stranger to virtualization. The company for years has carved up partitions on the mainframe. “We really saw this as a disruptive technology…. We learned that you have to characterize the environment upfront and take a phased approach,” says Ulrich Seif, CIO of the Santa Clara company. “So look initially at the low-hanging fruit and take those applications that are occasionally used and roll them in first.”
Application servers with a small user base or scheduled, predictable demand are good candidates, says Paul Mackey, National’s Windows server architect. “Then work up the chain to more critical applications,” Seif adds.
Harry Williams, director of technology and systems at Marist College in Poughkeepsie, N.Y., agrees users should start small — literally. “Start with smaller servers,” says Williams, who’s running a handful of virtualization technologies, including mainframe virtual machines, VMware, open source Xen virtual machine monitor and User Mode Linux. “Don’t pick four servers that run 100 per cent CPU bound, each using 4GB of memory, and expect that you’ll be able to put them all on one single server of a similar size,” Williams says. “Pick servers that have peaks and valleys of usage. You might have to get a slightly larger machine than you would normally deploy, but a single machine is still easier and cheaper to run than four slightly smaller machines. Expect that you will have to adjust settings as you proceed. It will not be perfect the first time.”
3. Be mindful about management. You must be able to tinker with how virtualized systems are managed. Server consolidation and cost savings have driven the use of server virtualization, but with the technology becoming an important part of a dynamic data centre, the ability to provision and allocate the servers becomes crucial.
Electronic Data Systems (EDS), in Plano, Texas, uses VMware and Microsoft Virtual Server technology for virtualizing servers that support Web hosting and other applications. It tops that off with management tools from VMware and InfiniBand switch vendor Topspin Communications, a 2003 Network World start-up to watch whose acquisition by Cisco is pending.
EDS uses Topspin’s VFrame management software to enable the InfiniBand switches to provision servers, storage and networks according to policies and rules, and VMware’s VMotion technology to direct how virtualized resources are provisioned and used.
“You need good tools to manage a virtualized environment,” says Robert Keahey, director of IT outsourcing architecture at EDS. Without such tools, you could easily find that you have implemented too much virtualization, he says.
“If you don’t have the management capability in place to control the environment, then you could run into a situation where you might start thrashing your servers around by moving workloads when you don’t need to,” Keahey says.
4. Know when to say “when.” That leads to a final point: Know when server virtualization will save money and boost efficiencies and when it doesn’t make sense.
As IT managers become more comfortable with server virtualization technologies, they might rush to virtualize everything. But users say virtualization isn’t always the best approach.
“If you have an application/server combination that’s well tuned, it makes no sense to put another layer of abstraction into that environment,” Keahey says.
Performance drags, and costs become issues, because virtualization tools can hit servers with both.
“On a case-by-case basis, you have to decide if upfront costs are going to be worth the savings in time and maintenance later,” says Justin Schumacher, software and systems design engineer for Adaptive Instruments, an industrial sensor product company in Hudson, Mass.
The bottom line for server virtualization: Understand what you’re trying to achieve. Gordon Haff, an analyst with Illuminata: says: “Almost forget about the term ‘virtualization.’ “Just think about what you are trying to do and look for the tools that will help you get where you want to go,” he adds.