Virtualization software vendors like Oracle, VMware and Microsoft often tout the ecological or “green” benefits of the popular server consolidation technology with phrases like “greater efficiency” and “power reduction.”
But to get the most out of a “green computing” strategy with virtualization at its core, IT professionals need to put down the marketing collateral and start analyzing precisely how power is used within their organizations, according to virtualization software analysts and users.
“With virtualization you run fewer systems at higher levels of utilization,” said Donald Feinberg, an analyst with Stamford, Conn.-based Gartner Research Inc. “Virtualization is one of the things that brings ‘greener’ to the table.”
And Oracle shops, left wondering about Oracle's virtualization support policies and what the company would do with its acquisition of Virtual Iron, may soon have some new options when it comes to managing and running their virtual servers.
Virtualization technology today is a fundamental component of many IT departments’ green computing initiatives. The software makes for more efficient use of data center resources by allowing physical servers to be consolidated into one or more virtual servers, which typically run on commodity hardware. More efficient use of resources means less hardware and power consumption. Less hardware and power consumption means financial savings and a smaller carbon footprint.
One of the chief appeals of virtualization beyond basic server consolidation is that it’s a green technology that makes sense from a financial standpoint. Analysts say that green computing virtualization is a powerful selling point because the rising cost of energy has just about everyone looking to reduce energy consumption.
Gartner estimates that most enterprise data centers will soon spend as much on power as they do on hardware. Framingham, Mass.-based analyst research firm International Data Corp. estimates that unused server capacity worldwide equates to approximately $140 billion in power costs and produces 80 million tons of carbon dioxide annually.
“Virtualization is the biggest part of what we’re doing [from an environmental standpoint],” said Mark Panning, IT project manager for Creighton University in Omaha, Nebraska. “We’re also trying to go paperless, where we can go paperless.”
Using virtualization to dynamically manage power
While the latest advances in virtualization software and related tools can help users dynamically and proactively maximize energy savings as never before, analysts say that getting there requires each company to take its own eco-friendly path.
Gaining a keen understanding of exactly how energy is consumed within the data center is a good place to start, said Tony Iams, a virtualization and operating systems analyst with Ideas International in Rye Brook, N.Y. This can be accomplished, he added, by regularly taking metrics on applications and servers and paying particular attention to CPU usage, memory usage and disk I/O.
Armed with that knowledge, companies will then be in a better position to get the most out of the newest virtualization tools, which take full advantage of the fact that virtual machines can be easily moved around.
Oracle VM, VMware and Microsoft Hyper-V are examples of hypervisors that offer what VMware calls “Live Migration,” the ability to proactively shift workloads to fewer physical servers without downtime. Iams said this function is key to proactively managing power consumption.
“Dynamic power [management] hinges on the ability to move virtual machines around without shutting them down,” he said.
The virtualization management layer is becoming more important than the hypervisor itself, Iams added. For example, Oracle recently announced that Oracle Enterprise Manager (OEM) -- its popular systems management and monitoring tool – will become the central management console for its virtualization offerings, including those acquired in the company’s $7.4 billion purchase of Sun Microsystems. In essence, Iams said, OEM will serve as the bridge between Oracle and Sun virtualization technologies.
“If you have the right management platform and you put that together with live migration, you could then take [power management] to the next level,” he said.
For large companies with multiple data centers, that could mean proactively moving virtual workloads from one geographic location to another based on which area offers the lowest electricity rates.
“It’s a little ambitious, but you can optimize your power consumption on a wide area basis,” Iams said.
Software, hardware advances should not be overlooked
Oracle VM 3.0, due out later this year, will incorporate the advanced power management features of another Oracle virtualization product -- Virtual Iron -- and, as a result, users should get a boost in terms of energy efficiency, according to Chris Wolf, virtualization analyst with Midvale, Utah-based Burton Group.
One of those power management features is Virtual Iron’s LivePower, which gives users the ability to reduce power consumption by dynamically and automatically allocating virtual machines across physical hardware according to demand. LivePower, which operates based on preset rules, monitors the CPU utilization of each virtual machine and can move VMs between physical servers to reduce power usage. Users can also set policies that enable LivePower to shut down physical servers that aren’t needed.
Software-based power management capabilities like LivePower will be highly useful to Oracle VM 3.0 users, but Wolf said it’s also important to take advantage of the latest energy management features found in today’s hardware.
“When you virtualize Oracle databases in general, regardless of the virtualization platform, you want to make sure that they’re on hardware that supports hardware-assisted memory virtualization,” Wolf explained. “From Intel, that would be called Extended Page Tables, or EPT; and from AMD, that is called Rapid Virtualization Indexing, or RVI.”
Hardware-assisted memory virtualization speeds things up by allowing the virtual machine to manage its own physical page tables in memory, he said, as opposed to virtualizing physical memory itself.
“If you’re virtualizing Oracle, you want to be on a platform like the Intel Xeon 5500; and in doing so, you actually start to realize some green benefits,” Wolf said. “The Intel Xeon 5500s have hardware-assisted power management, which means that they will automatically -- or in conjunction with the hypervisor -- do things like step down the CPU frequency [and] lower voltage to save power as the workload permits. That is a big consideration that a lot of people overlook.”