In the "old days," office workers used what were called "dumb terminals" – dumb in that the devices were simply conduits to applications and information stored on mainframe computers.
Then, mainframes gave way to network computing and the use of thin clients – computers that rely on servers to perform transactional roles. Today, these technologies have merged, and re-emerged as client virtualization. The concept, says Anil Desai, an independent IT consultant, is exactly the same.
The declining cost of desktop devices basically killed the use of dumb terminals. But recently, dramatic reductions in the cost of thin clients, along with administrative benefits of centralizing software and processing in the data center, have caused the idea of the dumb terminal to re-emerge.
What's more, the proliferation of smartphones, netbooks and tablet PCs coupled with the ability to control and deliver applications and data from a central location to multiple devices has made client virtualization increasingly attractive. Some of the benefits of the technology include reduced administrative costs, enhanced flexibility and increased security.
Understanding Client Virtualization
Client virtualization is often misunderstood. Broadly, the term can encompass both desktop virtualization and endpoint virtualization. Although all of these terms may be used interchangeably (along with presentation virtualization and application virtualization), they mean different things.
"The central benefit around client virtualization is to enable the user environment to be controlled and managed from some central point," says Eric Croswhite, worldwide product marketing manager of thin client solutions at HP. This is done through some combination of desktop and endpoint virtualization.
Desktop virtualization basically involves delivering a user experience to an end user, says Paul Christman, vice president of state and local government and education sales for Quest Software. "A desktop to us means an application and an environment to run it in.
"Think of the apps as being able to go down to the end of the wire," he adds. "It doesn't really matter what you have at the other end – whether it's a PC or Mac or an iPad."
In addition, says Calvin Hsu, senior director of product marketing for Citrix Systems' Cloud App Delivery Group, desktop virtualization provides the ability to run multiple end-user environments from one device.
Citrix XenClient applications, for example, let users establish policies and controls around those various environments so that one environment can be completely isolated from another.
Added security can be provided through Citrix Synchronizer, which ensures that the machine gets copied back centrally. "It's kind of like an automatic backup mechanism," Hsu says. "If the device is lost or damaged, the entire environment can be readily recovered on another device, which is a benefit particularly useful for notebooks."
One way to think about client virtualization is to realize that it's effectively breaking the operating system away from the hardware, says Raj Mallempati, director of product marketing for end-user computing at VMware.
"We're isolating the desktop operating system from the underlying hardware," he says. "The advantage is that now this operating system is completely secure and can run either in the data center or on any other device."
"Endpoint virtualization is all about the stuff that's in the desktop that a user needs to do his or her job and be productive," explains Brian Duckering, senior product marketing manager for endpoint virtualization at Symantec.
"Virtualizing applications is probably the biggest area here because it's the most challenging to solve," he adds. Once an application is virtualized, many things are possible, Duckering says.
- Multiple versions of a virtualized endpoint application can be available for use on a single machine: Think of a printing company that might receive files in various formats from multiple clients.
- Virtualized applications can be available on demand through application streaming: Users can acquire apps in just seconds, bypassing the conventional installation process.
- Profile and data virtualization can travel with users: IT can easily establish users on devices without having to physically move user information and data stores.
As these examples illustrate, both IT and end users benefit from client virtualization, but in different ways.
Weighing Benefits and Challenges
Client virtualization basically provides end users with a flexible way to access their applications and their data – and by extension, their desktops – from multiple devices. Along with this, it offers IT the ability to control the computing environment.
That control reduces the operating costs associated with managing desktops and applications. The systems team also has the ability to manage the security of applications, data and access.
"The benefit for end users, once you start going down the path of client virtualization, is that it provides self-service," Mallempati says. "They can basically go to a website and download a virtual application and run it on any device."
For increasingly overworked and understaffed IT departments, client virtualization provides a benefit in terms of decreased dependence on human resources. One person can actually manage more desktops and notebooks. And service providers can also manage IT resources remotely.
"Desktop virtualization often forces compromise, with the strongest arguments for virtualizing the desktop coming from the IT community, not the users," Duckering says. This makes it vitally important to show users that their service will improve – in that they will be assured quicker response times when problems arise – when they are not tied to a distinct device.
Historically, another hurdle has been provisioning client virtualization solutions for disconnected users. But technology advancements are removing this barrier.
"The way we've solved this is first in terms of application virtualization," Mallempati says. "The application can run natively on the PC. And from a client virtualization point of view, we've introduced a local mode or offline desktop. So now, at least with the VMware solution, it's not a drawback."
The technology is continuing to evolve. In the past, thin clients have appealed to a niche part of the market that might be defined as task workers, as in a call center. But with virtualization, it's now possible to deliver richer content over the network – multimedia experiences similar to what one would see on a traditional desktop.
The Case for Client Virtualization
Costs involved in client virtualization can vary widely depending on what kind of virtualization technology a business selects and how it plans to use it. The number of endpoints a company needs will be a large factor in determining implementation costs.
Despite the variability in costs, Mallempati says, "if you look at the overall cost of ownership to move to client virtualization, it's approximately 50 percent less overall."
The key cost components are back-end servers, storage, upgrading and updating front-end devices such as thin clients or PCs. Companies also must consider endpoint virtualization software, such as Citrix XenDesktop or VMware View.
Although organizations can make a clear and compelling case for server virtualization (fewer servers equates to immediate savings in capital IT expenditures), the case for client virtualization typically will not be as clear-cut.
"Server-side resources are so much more expensive than desktop-side," Desai says. This can make the potential for savings less obvious at the start.
Instead, the IT team will need to show the savings in time and human resources that the business can expect to recoup by centralizing maintenance and support. Also, the lifecycle for thin client devices tends to be longer than for traditional desktops, so total cost of ownership will decrease.
However, there are certain situations in which a business case can readily be made. In some niche settings, such as when companies want employees who work outside the country to be able to access applications or data, the benefits are obvious.
"Rather than giving direct network access through company firewalls, IT can create a virtual machine and have them work on that," Desai adds.
Another common usage case is for single-application users – at large call centers, for instance. "When everybody is using one central Windows application, there's no point in them each having their own computer and all the maintenance," he says.
Organizations with a large contingent of remote workers can also benefit from client virtualization, which provides enhanced data protection without the need for an investment in new security appliances and products.
"Virtualization is all about standardization," says HP's Croswhite. "That's what IT wants to do – that's what support managers want to do. They want to support one thing many times."
Tips for Implementation
At the outset, it's important for organizations to have an understanding of the benefits they hope to attain through client virtualization. Organizations really need to be specific about the technologies, goals and objectives they have.
"You need to have a very clear understanding of what it is you want to do, what it is you want to accomplish, and who your target audience is," says Richard Csaplar, a senior virtualization and storage analyst with the tech analyst firm Aberdeen Group.
"It's very important to assess the existing PC environment because it helps identify the right use cases," Mallempati says. "Client virtualization is not a solution for all types of users."
The IT staff needs to inventory the existing infrastructure, create performance baselines and then detail what it will take to actually replicate or provide better performance in a virtual-client environment.
As for endpoint virtualization, the experts suggest that organizations look for virtualization suites that they can purchase and implement modularly. This eliminates the need for a so-called forklift overhaul of the entire IT infrastructure, which can be costly and have a negative impact on the organization.
Symantec's Endpoint Virtualization Suite, for instance, includes three primary solutions that can be implemented into an existing IT infrastructure together or separately: workspace virtualization, workspace streaming and workspace corporate/remote.