The reality of virtualization
- By John K. Waters
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.
The Big Idea
One host, multiple guests
- About 5 percent of new operating systems
were installed on virtual servers in 2005. The
main reason is cost reduction, Gartner says.
- Analysts predict the virtualization market
will skyrocket. By 2009, Gartner estimates
40 percent of new operating systems will be
deployed on virtual machines.
- With virtualization software in place, many
enterprises will benefit from operational
agility supported by VM management tools.
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
"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
A buzzword defined
"Virtualization" refers to a framework or methodology for pooling IT resources
in a way that masks from users the physical nature and boundaries of those
resources, explains Gartner analyst Tom Bittman. As the term is currently
applied, there are three basic categories of virtualization:
- Storage virtualization, which pools physical storage
from multiple network storage devices so they appear to be a single storage
- Network virtualization, which combines resources in
a network by splitting the available bandwidth into independent channels
that can be assigned to a particular server or device in real time.
- Server virtualization, which masks server resources,
including the number and identity of individual physical servers, processors,
and operating systems, from users. Server virtualization software comes
in three flavors, including:
- Hosted: The virtualization software runs on top of
an operating system.
- Hypervisor: The virtualization software has its own
kernel and is installed right on the bare metal.
- Paravirtualization: A type of virtualization in which
the operating systemOS is aware it has been virtualized. In this approach,
the OS is modified to run on top of the virtual machine monitor (VMM),
which typically results in better performance.
—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
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
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
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,
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
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
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
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
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
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
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
"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
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."