In-Depth

The reality of virtualization

• By John K. Waters
• June 1, 2006

It's rare that an analyst suggests the hype about virtualization is less than the tech's true potential, but Tom Bittman, VP and distinguished analyst at Gartner Research does just that: "We think there's value [in virtualization] that the market doesn't yet fully appreciate."

Demand for virtualization—particularly for x86 servers—has become a tsunami smashing into the tech industry. Virtualization's potential is so great that it's driving product strategies at Microsoft, which announced in April that it will support mixed environments, and at chipmakers Intel and AMD, which are building virtualization capabilities into their CPUs.

No more than 5 percent of new operating systems deployed last year—counting all the Windows and Linux licenses—ended up on virtual machines, estimates Gartner. However, more than 40 percent of new OSes will be on VMs by 2009, analysts expect. And that forecast may be conservative, the researcher says.

"We have one scenario that says it could grow to 55 percent," Bittman confirms. "I've talked to about 700 customers so far who are going through this process at one stage or another."

Path to agility
For most companies of any size, the issue is not whether to virtualize their server infrastructures, but which solutions to use. So, the question is: With all this awareness, all this demand, and all these percolating plans, what exactly has the market failed to appreciate about virtualization?

"The number one draw to virtualization is cost reduction," Bittman explains. "Mostly it's server equipment, because this is a great way to consolidate hardware. So that's where they start, and that's the loudest buzz right now. But once they have the virtualization software in place, they begin to realize a range of agility benefits that really aren't widely considered right now. The ability to grow and shrink a VM, to move a VM, and to use VM technologies for disaster recovery are benefits that are going to be increasingly important as this trend unfolds."

A virtualization vision
VMware is not only the virtualization market leader, it's also the market catalyst. Virtual machine technology has been around for decades, but the latest generation of products designed to provide a logical, rather than a physical view of x86 computing resources, was born in a market created by Stanford University Associate Professor of Computer Science Mendel Rosenblum. He co-founded VMware with his wife Diane Green, Stanford grad students Edouard Gugnion and Scott Devine, and Berkeley engineer Edward Wang, back in 1998.

"Virtualization started out on the mainframe and then died out completely, because people thought the reason you did it was because computers were so expensive," Greene says. "And then computers got cheap. When the x86 architecture was done, there was no support for virtualization."

It was Rosenblum's research on operating systems that lead to the rebirth of virtualization. He didn't invent the approach, Greene admits, but he found a reason to take another look at it. "Mendel had the insight," she says. "He saw the value of revisiting the virtual machine and doing some new things with it. We modernized it and brought it to industry-standard systems."

To get people interested in their software, the company's founders realized they needed what Greene calls a drop-dead simple reason to use it. "We decided to introduce it on the desktop as a way to run Linux apps on your Windows machine," she says. "A lot of people thought that we were just a Linux tool, but we had bigger plans than that."

"We didn't think that any enterprise data center would buy a virtualization layer from some little start-up that was just pioneering the idea," Rosenblum says. "At that time, Red Hat had just done their IPO and Linux was taking off, and we just said to the market, 'Here's how you can run Linux and Windows together.' That wasn't really the vision when we started the company. It was just a way to get [our technology] out there and to get people to test and prove to themselves that it works."

The company grew fast, and just as virtualization began to enter the mainstream lexicon in 2003, the founders sold their business to EMC, and continue to run the operation as an independent subsidiary.

Rosenblum still teaches at Stanford, and as VMware's chief scientist, still advances a vision for virtualization beyond his company's current successes in the x86 server market.

"I see all of this leading to a pretty radical change in the way we think about our computing environments," he says. "When we started this company, the ingrained model was, you buy a machine, layer an OS on it, and then you put your applications on top of that. The OS was viewed as something that was intimately tied to the hardware, even part of the personality of your system. With the virtualization layer, the hardware is now just a pool of resources. That's a very different way of thinking about things. Our vision is of a virtual infrastructure where you don't really worry about the hardware underneath."
-John K. Waters

When Covenant Health, a Knoxville, Tenn. healthcare system of five acute-care hospitals, began looking at server virtualization solutions in 2003, it wasn't to take advantage of architectural agility.

"It seemed like every Monday we'd come in to work and there'd be three more servers," says Covenant's Senior Systems Analyst Bill Dean. "And we weren't adding them to expand capacity and performance, but to segregate applications. We needed environmental isolation, to be able to install multiple instances of Windows on the same piece of hardware. So we had all of this hardware using only 5 to 10 percent of their capacity. That was as frustrating as anything."

Covenant Health deployed VMware's ESX Server product in January 2004, which allowed the company to reduce the number of production servers in its 5,000-square-foot data center by 100, and to consolidate 10 test-and-dev servers into one virtualized server. Covenant now deploys 75 percent of its apps on VMs. Provisioning time is down to less than a day, Dean says, compared with the month or more required with the previous architecture. The company reported savings of $155,000 in the first 18 months.

What surprised Dean and his team was the operational agility virtualization added to Covenant's IT infrastructure, which VMware enables with its VirtualCenter and VMotion management tools. "VMotion is a small thing," Dean says, "but it's turned out to be a very advantageous technology that just wasn't possible until recently. If someone had said 5 years ago that I would be able to take a running machine and move it from one piece of hardware to another, I'd have said that it was impossible. I suspect that this will prove to be one of the more valuable aspects of virtualization."

Gartner's Bittman agrees: "VMotion isn't going to be the reason VMware gets in the door," he says, "but anybody who deploys VMs in large quantity will end up using a tool like VMotion, period. In fact, it becomes invaluable."

EMC's VMware is far and away the market leader in x86 server virtualization. A Forrester Research global survey of 1,221 enterprises found that 33 percent were using virtualization, and 13 percent planned to implement pilot programs within the year. The highest adoption rate was in North America, with 41 percent of enterprises already implementing or planning pilot server virtualization programs. Nearly half of those companies report that they are deploying solutions from VMware.

Virtual race
VMware products dominate the x86 virtualization market. But Microsoft's Virtual Server is gaining market share in Europe, with 38 percent of the surveyed companies there choosing the Redmond software maker's virtualization solution, and 30 percent choosing VMware.

Microsoft came late to this party; the Redmond software giant got into the virtualization business with the purchase of Virtual PC from Connectix in 2003. VMware was founded in 1998 and acquired by storage powerhouse EMC in 2003. Microsoft now has its virtualization program in high gear, and it has promised to release its in-development Windows hypervisor technology, code-named "Viridian," in the Windows Server "Longhorn" wave. Unlike a hosted virtualization solution, a hypervisor doesn't require an OS; it runs on "bare metal."

What seems to have gotten Microsoft off the virtual dime, though, was not VMware, which has had a near monopoly until very recently, but the swift market entry of an open-source virtualization project called Xen. According to Gartner's Bittman, Microsoft sees Xen as a greater threat.

Among other things, XenSource, the commercial entity that leads the open-source community and sells value-added enterprise solutions based on Xen, is planning to take advantage of new virtualization features built into AMD and Intel server processors. Intel's Vanderpool and AMD's Pacifica are CPU extensions designed to simplify the creation of VMs and other management operations. They're designed to make server virtualization simpler by allowing an entire client OS to be run in a secure sandbox, separate from management tools.

These new hardware virtualization features will allow Xen to run Windows without modification, Bittman explains. "That's what lit a fire under Microsoft to get focused on a hypervisor," he says. "They saw Xen coming, and the idea of open-source hypervisor was seen as being a much bigger threat than VMware. A commercial vendor they understand, but Xen is this open-source thing that could cause some serious disintermediation."

Now the competition is heating rapidly among Microsoft, VMware, XenSource and a handful of newcomers, such as SAP-backed startup Virtual Iron. VMware is giving away its lower-end hosted GSX Server, and plans to open up the source code of its ESX Server hypervisor product to key partners. Microsoft has begun giving away Virtual Server 2005 R2, and the company says it will support Linux guest OSes running on Virtual Server 2005 R2, including nine variants of Linux, all from Red Hat and Novell. Those two companies plan to integrate Xen Red Hat Enterprise Linux 5 and SuSE Linux Enterprise Server 10, into their core Linux distributions.

The result of all this competition is a hastening of commoditization in the virtualization market, Bittman says, which will ultimately shift the competitive field from the VMs to VM management solutions. Products like Microsoft's upcoming "Carmine" Virtual Server Manager, for example, will compete directly with VMware's VirtualCenter. Microsoft has not said when it will release Carmine.

The virtualization landscape
Virtualization is an evolving and somewhat loosely defined product category. Here's a list of vendors with software that falls solidly into the server virtualization category:

Last year, Cisco Systems acquired Topspin Communications. Topspin's server fabric switches are a relatively new class of server networking equipment designed to provide a high-performance, programmable infrastructure for grid and utility computing, clustered enterprise apps, and server virtualization.

Hewlett-Packard has pushed aggressively into the virtualization market with a portfolio of products for its servers, including the HP Virtual Server Environment for HP Integrity servers, HP-UX 11i virtualization capabilities, OpenVMS on virtualized Integrity servers, and packaged software with VMware and HP ProLiant Essentials Virtualization Management software, among others.

Big Blue's secure hypervisor, sHype, is a virtualized architecture developed by IBM Research. sHype is designed to provide strong isolation, mediated sharing, and communication between VMs. IBM also has developed a security extension to the open-source Xen hypervisor that allows administrators to define simple policies that govern the control and sharing capabilities of VMs running simultaneously on a single Xen system.

The Levanta System is a Linux management and data virtualization solution. It is designed to combine change control with data virtualization for faster and more flexible control of Linux on commodity hardware, racks, blades, boxes, VMs, and mainframes.

Leostream develops apps designed to manage server virtualization products from VMware and Microsoft, and integrates them with SANs from EMC, HP, and IBM.

Microsoft's Virtual Server 2005 R2 is a virtualization platform designed to run most major x86 OSes in a guest environment. Microsoft supports it as a host for Windows Server OSes and system apps.

Parallels offers two virtual software products, and is readying two more. The Parallels Workstation is desktop virtualization software that enables users to create multiple independently operating VMs on a single PC. The Parallels Compressor is a performance enhancer for VMs from VMware or Microsoft. The Parallels Server and Parallels Enterprise Server products are due late this year, and can be downloaded for evaluation.

PlateSpin is a start-up that's riding the shift of data centers back to virtualization and consolidation. The company's Operating System Portability technology is designed to allow OSes, data and apps to be moved between computers from a single control point. PlateSpin's products include PlateSpin PowerConvert, PowerRecon, and PowerSDK.

Scalent's Virtual Operating Environment enables general-purpose utility computing with an infrastructure that allows resources to be treated as a single pool. The infrastructure pool contains bare-metal servers (HP, IBM and Dell), virtual servers (VMware, Xen and Windows Virtual Server), appliances, and commodity LAN and SAN fabrics.

Sphera is a Software-as-a-Service provider whose Virtual Dedicated Server technology is designed for both OS and app virtualization.

Sun Microsystems markets Solaris containers, its VM technology. It also partners with VMware to allow server virtualization on Sun Fire x64 (x86, 64-bit) servers and the Sun StorEdge 6920 system. Sun is a participant in the open-source Xen project.

SWsoft's Virtuozzo for Windows & Linux Server Virtualization is designed to create multiple virtual environments on a server. Each Virtual Private Server performs and executes like a standalone server, and can be rebooted independently, with its own users, IP addresses, processes, system libraries and configuration.

ToutVirtual's VirtualIQ is a suite of system and security management tools for enterprises deploying virtual infrastructure platforms. Powered by the company's ToutVirtual System Resource Broker technology, the products in the suite work in a closed-loop system that is virtualization-aware and platform neutral.

SAP-financed startup Virtual Iron provides Xen-based, enterprise class virtualization software. The Open Virtual Iron for Xen, Community Edition is available with a GPL license; the Virtual Iron for Xen, Professional Edition also is free. The Virtual Iron for Xen, Enterprise Edition, available with a commercial license, includes Virtualization Services and a Virtualization Manager. The Virtual Iron Cluster Edition is a commercial product built on the Virtual Iron hypervisor to provide support for high performance computing clusters.

The undisputed leader in server virtualization market, VMware markets VMware ESX Server, the company's virtual infrastructure software for partitioning, consolidating, and managing servers in mission-critical environments; and the VMware Workstation, desktop virtualization software for developers and testers who run multiple OSes simultaneously on a single PC. The company also sells a number of management tools (VMotion, P2V Assistant and ACE), and two free products: VMware Player, which runs any VM on a Windows or Linux PC; and VMware Server, which provides virtualization for Windows and Linux servers.

Win4Lin provides virtualization software that enables users to run Windows within a virtual environment on Linux. Its Win4Lin Virtual Computing Environment is used by Fortune 500 enterprises, educational institutions, SMBs and desktop users. Its products include the Win4Lin Pro Desktop, Win4Lin 9X Desktop, Win4Lin Pro Terminal Server and Win4Lin 9X Terminal Server.

XenSource leads the open-source Xen community, and sells value-added products based on the Xen virtualization technology. These include XenEnterprise, the first commercially packaged and supported Xen solution, and Xen 3.0 open-source hypervisor. Xen 3.0 supports Intel VT, 32-way SMP, PAE,and 64-bit addressing.
-John K. Waters

Game-changing technology
It will also open the door even wider for third-party innovation. Companies like Akimbi Systems, will have an edge as providers of niche virtualization management products.

The company's flagship virtual lab automation system, Akimbi Slingshot, is designed to automate the set up and tear down of complex, multi-machine software configurations on a centralized pool of servers shared by enterprise app dev and QA teams. Basically, it allows orgs to pool and share servers, storage and network equipment resources.

"The improved manageability is really the most interesting benefit derived from virtualizing the data center," says Akimbi's CEO James Phillips. "When it's easy for me to bring up and bring down resources, move them around, allocate more resources where apps are really in need, more easily implement disaster recovery plans-all of those things are facilitated by virtual machine technology. I think that's where the tremendous upside is, where it's not just an efficiency thing, but a game-changing thing relative to the way large enterprises run their information technology organizations."

Roy Rezac, director of engineering at RSA Security, would probably agree with Phillips' assessment. Virtualization technology has become an important part of RSA's engineering strategy, enabling the Bedford, Mass. company to provide its developers with a flexible and configurable-on-demand environment, while cutting costs. The company is a VMware customer and has been using the VMware ESX Server.

But when he learned last summer that his group, which engineered the RSA Sign-On Manager, would soon be responsible for six more products, Rezac concluded the group would also need a system that could manage version control, configuration and quick deployment of virtualized images for the software dev team.

"We looked at this transition coming to my organization," Rezac says, "at the number of servers we were going to need times the number of products, times the number of versions, and we all agreed that we needed help."

Rezac says he and his team homed in on Akimbi Slingshot because it was optimized for the software dev lifecycle.

"Before we had the Akimbi system, if an engineer wanted to go and test their client's software in the environment, they would have to set up between two and eight servers," Rezac says. "That takes—if they're really good, and all the hardware is available—hours. Generally, it takes days. With Akimbi, they can basically check pre-configured servers out of the library and do it in two to three minutes. That's massive for me in terms of productivity."

The proliferation of server virtualization technology is likely to have another side effect that has yet to hit the hype cycle: a relatively big, but short-lived, impact on the x86 market. Gartner expects revenues in this market to flatten for 3 or 4 years, and possibly even decline.

"Virtualization is forcing a better use of compute power," Bittman says. "So over that period, we'll see a bit of a crunch. But after that, utilization rates will go up on average, and we'll see growth continue again. It's going to cause a lot of pain for the x86 vendors."