Desktop Virtualization:
An Expert Guide to the
Benefits and Challenges
While there are obvious benefits associated with desktop
virtualiza-tion, including simplified desktop management, developing this
virtualized environment is no simple task. In this expert E-Guide,
brought to you by SearchEnterpriseDesktop.com and Dell, you will
gain insight into the top reasons to deploy virtual desktops in your
organization. Discover the unique advantages offered by desktop
virtualization, including the ability to quickly and reliably deliver
desktops to any linked location. Explore a comprehensive analysis
of the benefits and drawbacks associated with virtual desktop
technology.
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Table of Contents
Table of Contents:
Virtual desktop benefits that sell VDI
Virtual desktop software pros and cons
Four good reasons to deploy virtual desktops now
Resources from Dell, Inc. and Intel
Desktop Virtualization:
An Expert Guide to the
Benefits and Challenges
Virtual desktop benefits that sell VDI
By Danielle and Nelson Ruest, Site Contributors
Virtual desktop infrastructures simplify desktop management and reduce the typical issues faced when dealing with distributed desktops.
With VDI, desktops are delivered quickly and reliably to any linked location. You control which devices are linked to a virtual machine (VM) -- controlling data management and reducing the potential loss of intellectual property (IP). This setup also has a significant effect on the cost of each desktop, sometimes reducing it by as much as 40%. You can also reduce the number of images you must manage, especially when working with volatile PC images, or those that are created as needed when users log into the system. Patches and updates are also easier to apply since you often only need to update one core image.
VDI transforms the desktop lifecycle and reduces its number of components (Figure 1). Traditionally, you must procure, image, secure, deploy and then monitor, maintain, back up and retire your physical desktops. With VDI, you only need to generate the original image by creating a reference computer, use it as the core image for all systems, personalize it -- usually the VDI engine performs this -- and then monitor and update it. The desktop broker automatically retires the images when the user logs off.
Figure 1 Traditional desktop versus VDI lifecycles.
Virtual desktop benefits that sell VDI
Transforming and, in turn, simplifying the desktop lifecycle is just one of the major benefits of VDI. Other advan-tages include the following:
• You can provide centrally managed desktops to users on any endpoint device -- desktops, thin clients, Web clients and Pocket PCs or mobile phones.
• Central control enables you to lock down virtual desktops.
• Less time can be spent on endpoints -- actual physical PCs -- because they no longer need to be
managed as tightly. These endpoints are only needed to provide a remote desktop connection to the virtual desktop.
• Service-level agreements are only needed for the central desktop, not for the endpoint itself. Users can be administrators on the endpoints, but locked down on the virtual desktop.
• Knowing where the starting point for each PC is in regard to your golden desktop image can reduce costs and improve service stability.
• You can create locked and encrypted virtual desktop images that can be time-controlled to meet specific requirements. For example, if you have a staff influx to meet a seasonal business need, you can generate time-controlled PC images for this time.
• Keeping a virtual desktop inside the data center will secure information. This gives you more control over IP; you only need to lockdown the image you create so that it cannot access external devices. It's easier to maintain compliance when IP is stored centrally and does not leave the data center.
• Complex or sensitive applications can be encapsulated and isolated into specific PC VMs to ensure proper operation. Therefore, the application does not need to interact or coexist with other applications.
These are just a few of the benefits that centralized desktop virtualization can bring to your company. This versatile technology provides a new desktop operational model, making it worth the look.
Virtual desktop software pros and cons
By Stephen J. Bigelow, Senior Technology Writer
Desktop virtualization can be the solution to managing difficult endpoint computers, but first you need to know the pros and cons of virtual desktop software.
Every user's desktop is different, and system administrators often have little control over the variety of operating systems and applications running throughout the company. Troubleshooting typically requires significant time to verify drivers and patch levels, and admins must perform even the most routine software updates on every PC. When you realize that there may be hundreds, thousands or even more client endpoints, it's easy to see how support or maintenance projects can easily tax solutions providers -- and result in costly and time-consuming projects for customers.
Virtual desktop software is a means to combat endpoint complexity by shifting the desktop environment from each client to a virtualized desktop hosted on a server in the data center. The server then supplies the desktop environ-ment -- the operating system, applications, settings and more -- to each endpoint PC across the LAN.
Desktop virtualization pros
Desktop virtualization, also dubbed the virtual desktop infrastructure (VDI), is based on a thin-client computing model. In effect, the virtual desktop machine on the server side handles all tasks related to the OS, application processing (including visual rendering) and storage; the endpoint PC now acts as little more than a "dumb" I/O device.
Thin-client endpoints typically use some local software (often a basic OS to boot the endpoint and connect it to the desktop server). But some endpoints use a zero-client approach, which requires no software at all. These client endpoints normally boot in firmware with no local storage and connect directly to the desktop server.
The implementation of virtual desktop software offers a wealth of benefits for customers. At the hardware level, desktop virtualization saves money by easing endpoint hardware requirements. Existing PCs can serve as thin clients with no real modification, which extends their normal lifecycles. For example, a business may normally replace its PCs every two to three years, but a PC as a thin client may last five years or more.
Similarly, businesses can purchase new PCs and the new generation of thin client PCs far more economically, because thin-client endpoints don't need the same disk, memory or processing capacity as regular richly configured PCs. Reduced hardware requirements also mean lower energy usage, which fosters power conservation and a green environment, not to mention a quieter office.
Virtual desktop software pros and cons
When a conventional PC fails, repairs take time and expertise. Replacing a conventional PC requires the user or technician to reinstall applications, reset preferences and recover data (if possible). In a virtual desktop environ-ment, an administrator can swap out the faulty thin-client PC, and the user can continue working immediately --significantly reducing the time and expense normally associated with desktop support. In addition, a user can log into a virtual desktop from other endpoints, including remote PCs, without installing software or copying data to multiple systems.
Another notable benefit of virtual desktop software is superior administration. Virtual desktop management happens almost entirely at the server level. When a new desktop is needed, an administrator can provision a pre-established virtual image and deploy a thin-client PC with a minimum of time and effort. The admin can also allocate additional server resources to virtual desktops that require more processing power or scale them back for incidental and non-essential users. Deployment of new software, patches and upgrades for all virtual desktops can happen at the serv-er level, rathserv-er than on each individual PC.
Virtual desktop software also lends itself to enterprise security. Conventional PCs store applications and data locally, exposing the computers to viruses and spyware and risking data loss if they are lost or stolen. Virtual desktop machines use storage in the data center (true thin clients don't even have local storage), so there is no data to lose on the endpoint device. This design also centralizes antivirus, antispyware and other security products. Virtual desktops can allow some software installation flexibility for the user, but admins can also lock them down to pre-vent the installation of new or unauthorized applications.
Even disaster recovery planning is simplified with virtual desktop software. Conventional environments rely on PC users to back up their own data, but end users are notoriously inconsistent or infrequent with their backups, which usually leads to data loss in a disaster. Servers, on the other hand, are backed up routinely and consistently. A business struck by disaster can potentially recover and restore its virtual desktops to servers in a secondary data center and then allow users to access their desktops with little (if any) disruption.
Desktop virtualization cons
Virtual desktop software can solve a multitude of problems for customers, but solution providers need to consider some of the potential pitfalls before embarking on a desktop virtualization project. One of the first considerations should be the network bandwidth needed to support the traffic at each endpoint.
Ideally, bandwidth requirements are limited to carrying keystrokes and mouse movements to the server and return-ing screen refreshes to the endpoint. When you multiply this bandwidth by the hundreds or thousands of virtual desktops, it's easy to see how crucial network bandwidth is -- even when no application data is being exchanged. Solution providers should analyze their customers' available bandwidth and determine the requirements of a desk-top virtualization project. It may be necessary to propose network upgrades in advance.
For example, consider that smooth desktop emulation requires a display refresh rate of 30 frames per second (fps), and a typical desktop may run at 1280 x 1024 x 32 bits per pixel (bpp). That works out to 1.26 Gbps of uncom-pressed video data per desktop. Today, there is Windows Remote Desktop Protocol (RDP) and other protocols that can enhance remote graphics behavior while limiting bandwidth use through caching, compression and other tech-niques.
"If you have very high-end graphics capabilities, you have to have some combination of technologies that address graphics over the network," Goldworm said.
Support for external devices such as scanners, printers and smart cards has also limited virtual desktop adoption, as has support for multiple monitors, bidirectional audio and video, streaming video and USB devices. Today the development of virtual desktop software has overcome most of those limitations, but solution providers still must consider the performance needs of their end users and ensure that the prospective desktop virtualization platform will behave as expected. Most pre-assessments will include some lab work and evaluation to check compatibility with services or devices.
Solution providers should also consider the server resources available to support virtual desktops. Servers handle all of the processing and visual rendering for the virtual desktops, so the servers need significant processing and memory resources. In most cases, multiple servers (or even a blade server) will be appropriate to handle desktop virtualization.
But it's important to note that the total processing requirement is not the simple sum of all desktops. Rather it's a statistical mean based on the number of processing loads. For example, if you're replacing 100 desktop PCs with 2 GHz processors, you don't need a server with 100 2 GHz processors. In reality, PCs are idle much of the time, and it takes far less processing power to handle most basic operations. Virtual desktop software vendors can typically help solutions providers determine an adequate level of server processing and memory, based on the number of endpoints.
Solutions providers and customers should never attempt desktop virtualization projects without considering server redundancy.
"There's the issue of putting all your eggs in one basket," said Brien Posey, an independent technology consultant in Rock Hill, S.C. "If you've got all your desktops hosted on one machine, and that machine goes belly-up, then you're dead in the water."
Server clustering, redundant connectivity and other tactics are essential for any type of virtualization -- but espe-cially so for desktop virtualization, where a server outage can affect the entire user base.
Finally, storage is an issue that often goes overlooked -- until a customer realizes it's out of space. All of the pro-cessing is handled centrally, so all of the application data is stored centrally. Each virtual desktop needs the same amount of storage that would otherwise be present on the traditional desktop. For example, if the average PC stores 100 GB -- including the OS, applications and data -- there should be about that much storage available for each virtual desktop; if you're virtualizing 100 desktops, you'll need another 10,000 GB (10 TB) in the data center.
Virtual desktop software pros and cons
Four good reasons to deploy virtual desktops now
Michael Keen, Site Contributor
The benefits of virtualization far outweigh any limitations and the technology is rapidly reducing the gaps with the user scenarios playing out today. Developing a virtual desktop environment isn't an easy feat, but there are many reasons why it's worth the effort. The top four reasons to invest in virtual desktops now are:
• The desktop support cost reduction possibilities • Application and data security improvements • Software licensing management options • System stability and reliability
Reduction of desktop support costs
The provisioning of PCs is much simpler in a virtualized environment. With traditional desktops, administrators must test applications against multiple desktop configurations. With virtual desktops, IT can test applications against only one environment prior to deployment and still eliminate most follow-up support issues.
There are high cost and resource demands that come with managing a wide variety of client form factors, multiple generations of operating systems and hundreds of applications. Some well-managed PC environments require constant maintenance and support to repair problems and retain compliance with corporate policy. Desktop virtual-ization allows for large, global companies with thousands of PCs to better manage their clients because of the reduced dependence on specific hardware and operating system configurations.
Application and data security improvements
The traditional PC environment must be patched and updated consistently. There is a need to mitigate viruses and worms and cut the exposure of critical data and applications to malicious behavior from internal and external sources. Security risks increase as more mobile devices enter the workforce. End-users reach the internet through public and unsecured home Wi-Fi networks. Thousands of laptops are stolen every year, which put confidential corporate data at risk.
Because virtualized environments give IT greater control over system and application provisioning and access, it is easier to secure access rights, and in many cases, data. Desktop virtualization helps by making it easier to decouple applications from data, which also makes it easier to de-provision access to applications.
Software licensing management
How many applications in the enterprise do you run today that you have no way of tracking? If you deliver all corporate applications through a virtualized environment, it is easier to track software usage and licenses.
System stability and reliability
Virtual environments can help prevent application conflicts and are easier to repair when issues arise. There are ways to sandbox applications and prevent these conflicts. Plus, you can quickly and easily restore a PC to a working state with a simple reboot, thereby reducing the costs associated with reimaging and redeploying that hardware asset.
Four good reasons to deploy virtual desktops now
Resources from Dell, Inc. and Intel
