Virtualisation is unarguably one of the biggest trends of the past few years, and open source software has been on the IT radar for a while now. So does that make open source virtualisation twice as much of a good thing?
At least some corporate IT departments think so. They're turning to open source software as part of their virtualisation mix. Sure, savings are a big factor, but so is the ability to tweak the software to suit specific requirements.
Just ask Stan Yazhemsky, manager of IT operations at Legal Aid Ontario (LAO), which uses Citrix's XenServer, a management tool running on the open source Xen hypervisor.
XenServer's open APIs give him and his team of three Linux engineers better access to and control of advanced functions, especially security, Yazhemsky says.
LAO, a non profit corporation that provides legal advice and services to low-income individuals, has 200 locations across Ontario and hosts three data centres. Those data centres house 239 Windows servers and 68 Linux servers. Some 95% of LAO's servers are running XenServer.
LAO has 154 terabytes of sensitive data such as client/lawyer information, financial files and individual case loads that span everything from burglaries to theft and murder. Security is a key concern.
"If an attack manages to break into the system, our embedded script will shut down the compromised virtual machine immediately and bring another virtual machine up, in real time with no effect on users. That's something that you can't get from any closed source solution," Yazhemsky says.
As a result, the organisation is able to invest less in security than it would otherwise have to, he says. His calculation is that LAO spends about 40% less in security software and management costs than it would have otherwise, "because we can script events that proactively search for any changes," Yazhemsky says.
Open source virtualisation: tiny but growing
Despite its fans, the overall market for open source virtualisation is very small indeed, though it is expected to grow.
"Open source is less than 5% of the overall server virtualisation revenue market share, but could nearly double by 2012," says Alan Dayley, a Gartner Group research director.
Ope source hypervisors including Red Hat's KVM and Xen, used by both Citrix and Oracle, and the management tools running on top of them are gaining strength in both adoption rates and advanced features formerly found only in the likes of VMware, the virtualisation market leader, Gartner says.
Gartner's 2008 figures show that for the hypervisor market, in units not revenue, Citrix had 2% and Virtual Iron held 1%. For 2012, Gartner's projections are that Citrix will hold 6% of unit share, and Red Hat 2%.
Nevertheless, open source virtualisation will likely always remain a small piece of the pie. "While companies like Citrix and Red Hat are going to see great growth, they are not going to take significant market share," says Gartner analyst Phillip Dawson. "Most of the share change will be between Microsoft and VMware."
And that's a shame, says IDC analyst Gary Chen, because open source virtualisation software has a lot to offer. "A lot of people don't really know how good Citrix XenServer 5.5 has become," says Chen.
One potential huge market for open source virtualisation: cloud service providers. "If you're a large service provider and you're building a cloud, you may have very custom specific needs, [and] you may need to modify the source code and you can go with open source," Chen says.
As companies like Amazon.com build out their cloud computing strategy and virtualise literally thousands of servers in their data centre, they will be looking at vendors offering cheaper virtualisation solutions with well developed management tools that they don't have time to build, predicts Bill Claybrook, an analyst with New River Marketing Research.
Under this scenario, he says, Citrix's attractiveness will increase. "Citrix is one company out of all of those vendors that could make some money in cloud computing by providing a free Xen hypervisor and marketing its management tools at a reasonable price," Claybrook says.
Is Oracle's role broadening?
Oracle's recent acquisitions of Virtual Iron and Sun Microsystems, and their respective virtualisation technology, could prove interesting in the long term. While most observers expect Oracle's open source virtualisation software to be a hit primarily in existing Oracle shops, Sun's large customer base may give Oracle a chance to penetrate a greater number of corporate IT departments, says Claybrook.
"Oracle will probably end up with the largest open source for virtualisation installed base of any one of their competitors," Claybrook predicts.
For its part, the University of Massachusetts is running Oracle VM because it is such a huge Oracle shop in general, says Michael Poole, chief technology officer "It made sense to choose Oracle VM... especially with the significant number of Oracle applications we support." He says the university has realised significant performance gains and considerable cost reductions in its operations.
UMass is in the middle of an infrastructure transformation project that consists of many sub-projects. While planning a new primary data centre and a more robust disaster recovery and testing data centre, UMass investigated many options and chose to standardise on open source Xen virtualisation with Oracle VM and Oracle Unbreakable Linux support. UMass started implementing Oracle VM a little over a year ago.
By next summer, the target date for the infrastructure project's completion, Poole says the university will reduce its physical servers from 500 to fewer than 300. It also expects to save close to $100,000 (£60,000) a year in power and cooling costs alone. And UMass will have totally switched from VMware over to Oracle VM.
The university's IT infrastructure is managed and monitored with Oracle Enterprise Manager, and UMass makes extensive use of Oracle's PeopleSoft ERP, Oracle Enterprise Linux, Oracle DB, Oracle Real Application Clusters RAC and Oracle WebLogic servers. UMass is adding Oracle Business Intelligence Suite and the Oracle Identity Management Suite to its lineup.
"We're a big Oracle shop. It was important to us to buy into the logic that says Oracle is developing and testing all of their applications on the Oracle infrastructure components, including Oracle VM, and getting the kinks out of the system, or at least reducing them before they get into general release," Poole says.
Poole explains that one of the university's biggest successes to date has been the virtualisation of its Blackboard Vista learning management system. Through this, professors distribute content, exchange emails and engage in live discussions over the Internet with 63,000 students.
Before it was virtualized, the Blackboard Vista application ran on 40 separate Solaris-based application servers. Today the number of physical servers running the application has shrunk to 5 and performance has quadrupled, Poole says.
By using Oracle VM to virtualise Blackboard Vista, Poole says, We've seen a very significant reduction in hardware while at the same time dramatically improving upon performance and scalability."
But before going with open source virtualisation, it's important to have a staff with the right Linux/Unix background, recommends Richard Cote, systems architect and technical lead at the University of Massachusetts.
"If I were making a decision at a small company that only had Windows-savvy tech administrators I'd probably look at VMware or HyperV if I did not have a Linux or Unix group to support me. If you come from a traditional Unix-savvy staff then you're going to be drawn toward Xen," Cote says.
Small businesses may find much to like
Server virtualisation growth is expected to increase in small- to mid-size businesses, and there, too, open source could gain a foothold.
Gartner classifies small business as companies with 20 to 99 employees and less than $50 million (£30m) in revenue. Mid-size companies have 100 to 999 employees and $50 to $500 million in revenue. "We expect the [SMB] growth rate for virtualisation adoption to be higher than the overall market through 2012," Dayley says.
And even companies that are using VMware and/or Microsoft's HyperV may still find a place for open source.
Interactive One provides web properties for millions of African Americans and has split its IT infrastructure in two. Its office environment uses VMware to run Microsoft Exchange, Microsoft SharePoint and Windows File Server. On the production side, to power the websites, the company has deployed Oracle VM.
"We weren't a good candidate for VMware's advanced functionality because these boxes aren't mission critical, single point of failure systems," says Nicholas Tang, Interactive One's vice president of technical operations. "As a result, we don't do a lot of VM-level clustering and automated failover."
After discussing the possibility of using VMware for the firm's production environment, Tang's assessment was simple: "VMware doesn't do any better job than Xen does quickly building a virtual environment and efficiently reallocating resources. VMware cost two or three times more than what we paid for Oracle VM, and in the end it wasn't worth it."
Since using Oracle VM, Tang says, he's retired 60 servers, has realized greater utilisation of resources and is using open source tools like Fedora's Cobbler, a network installation tool, and other software like cfengine, a configuration management tool, to build more functionality into the company's virtual server environment.
While analysts continue to speculate, and vendors continue to improve their products, in the end, IT managers will have to make up their minds based on their needs.
"Customers have to do the tests, ask themselves will it work in their IT environment and will it meet their business requirements at the right price and with the right skills," LAO's Yazhemsky says.