desktop virtualization and evolving strategies for it...

Desktop Virtualization and Evolving Strategies for IT Service DeliveryJaime Halscott

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Desktop Virtualization and Evolving Strategies for IT Service Delivery Jaime Halscott

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Introduction to Realtime Publishers .................................................................................................................

Chapter 1: Understanding the Challenges of Building VDI Now for Future End User Service De

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livery ......................................................................................................................................................................... 1

De sktop Virtualization: Means or End? ..................................................................................................... 1

Pla nning .............................................................................................................................................................. 3

Licensing ........................................................................................................................................................ 3

The Goals of Desktop Virtualization ....................................................................................................... 4

Identifying How Users Interact with Desktops Is Critical ............................................................. 5

Lesson Learned ................................................................................................................................................ 5

Re liability ........................................................................................................................................................... 6

Speed ............................................................................................................................................................... 6

Supporting Offline Users ............................................................................................................................. 7

Understanding Internal Connectivity Needs ................................................................................... 10

Tackling External Connectivity Problems ......................................................................................... 10

Metrics for Ensuring Network Effectiveness ................................................................................... 11

Where Do Physical Desktops Fit? ......................................................................................................... 14

Summary .............................................................................................................................................................. 15

Ch apter 2: Smart Approaches for Merging Desktop Virtualization Today and Tomorrow .. 16

Le sson 1: How Legacy Solutions Integrate Into Service Delivery ............................................... 17

Take Inventory .............................................................................................................................................. 17

Analyze Supporting Components and Processes ........................................................................... 18

Adapting Server Solutions to Desktop Virtualization .................................................................. 20

How Management Solutions Fit ............................................................................................................ 21

Lesson 2: How the Cloud Affects Service Delivery to Users ........................................................... 21

Lesson 3: Technologies We Never Saw Coming .................................................................................. 23

Lesson 4: Finding a Home for Traditional VDI..................................................................................... 25

Lesson 5: When It Doesn’t Fit, Cut It Out ................................................................................................ 27

What’s Next ......................................................................................................................................................... 28


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Ch apter 3: Integrating Legacy and Emerging Technologies into IT Service Delivery ............. 29

Le sson 1: Finding the Right Ingredients to Make It Work .............................................................. 30

Option 1: Dual Duty Desktops ................................................................................................................ 31

Option 2: Replacement with Thin Clients ......................................................................................... 31

Option 3: Desktops as Thin Clients ...................................................................................................... 31

Choosing the Right Option for Physical Desktops in a Virtual Environment ..................... 32

What About Supporting Infrastructure Components? ................................................................ 33

Application Virtualization and Supporting Technologies .......................................................... 33

Le sson 2: Integrating the Old and the New into Something Coherent ...................................... 33

Shared Storage Needs ................................................................................................................................ 34

Networks and Supporting Technologies ........................................................................................... 34

Challenges to Integration ......................................................................................................................... 34

Le sson 3: The Technologies We Are Waiting For ............................................................................... 35

Improvements to Connectivity Required for Hosted VDI .......................................................... 35

The Required Evolution of Mobile Data Networks and Devices ............................................. 36

Thin Client Limitations .............................................................................................................................. 36

Increased Storage Demands.................................................................................................................... 36

Enhanced Network Management Solutions ..................................................................................... 37

Expanding VDI Adoption .......................................................................................................................... 38

Le sson 4: How to Determine You Got It Right...................................................................................... 38

Gathering Intelligence from Users ....................................................................................................... 38

Review Pre‐VDI Support Metrics .......................................................................................................... 39

What About New Support Challenges? ............................................................................................... 40

Le sson 5: What the Future Holds .............................................................................................................. 40

Problems for Widespread VDI Use ....................................................................................................... 41

Focusing on Service Delivery .................................................................................................................. 42

Implementing VDI Now with a Future Mindset .................................................................................. 42


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[Editor’s Note: This book was downloaded from Realtime Nexus—The Digital Library for IT Professionals. ll leading technology books from Realtime Publishers can be found at A http://nexus.realtimepublishers.com.]

Chapter 1: Understanding the Challenges of Building VDI Now for Future End User Service Delivery

Our industry’s trend towards virtualization quickly evolved from a buzz phrase to a storm. Server virtualization has been a great fit for a vast majority of companies, but can the same be said for desktop virtualization? There is no doubt that desktop virtualization and virtual desktop infrastructure (VDI) are emerging industry trends, but are they right for your exact business goals?

That is the question this guide intends to answer. Although building VDI is a goal of many IT organizations, does the excitement surrounding VDI technology obfuscate the business problems it intends to resolve? This book will serve as a guidepost toward effectively determining the best alignment between technology and business need. That guidepost can serve as both a directional marker and a warning—and the intention is to accomplish both. The aim is to help the IT architect determine what business requirements drive the move toward desktop virtualization as well as choose the right path in desktop virtualization.

Desktop Virtualization: Means or End? The IT industry finds itself in a quandary between technology and business requirements. Technology exists that dramatically improves the efficiency of the IT organization, but does the implementation of that technology in fact burden its users? Could an IT return on operational efficiency actually hinder the business in other ways? Determining whether desktop virtualization represents a solution or a means to that solution requires asking key questions:

• How does desktop virtualization align with end user service delivery?

• What additional benefits or enhancements to end user service delivery will come from the VDI project?

• Are those benefits cost justified?

• Do the desktop virtualization steps taken now align and integrate with future growth and other emerging technologies?



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Timing the transition from legacy desktop infrastructure to a method for anytime, anywhere user workspace delivery is critical. As IT budgets continue to tighten, no IT architect can or should realistically ask executives to approve replacement of infrastructure that “isn’t broken.” Thus, it is necessary to frame the entire endeavor around the true goal of end user service delivery. However, legacy desktops may be meeting the goal of end user service delivery quite well.

So the big question is, Why replace them? Desktop virtualization isn’t an end in itself. It is part of a path toward the evolving delivery of services to end users. This journey is transformative and won’t happen overnight. There isn’t going to be a technical solution to all of the problems that will be encountered. Desktop virtualization doesn’t address them all at this point and as a technology set, may never do so. Vendors have made great strides towards building technical solutions that we will address in detail; however, understanding where to leverage desktop virtualization and where not to is of the utmost importance.

Desktop virtualizers face a whole new set of challenges from their server counterparts. Even seasoned IT architects familiar with the aspects of a successful server virtualization project can be caught off guard by the differences between server and desktop virtualization. Understanding these critical differences is crucial to a successful project.

Reference Later chapters will analyze the differences between server and desktop virtualization with the goal of better understanding which technologies fit which future goals.

In addition, technologists must identify the reasons for the project in the first place and answer key questions: Why virtualize desktops? What is driving the VDI initiative? If the reasons and challenges aren’t thought through and addressed at the onset, the project will quickly fall short of the business goals. Technical challenges are just part of the problem. End user training, awareness, and expectations are vital elements to address throughout the process. Let’s start with a series of lessons designed to help you understand how desktop virtualization differs from server virtualization.

At the core, there are a lot of similarities. However, the implementation of desktop virtualization introduces challenges. We will analyze those challenges and come to an overall determination of whether desktop virtualization should even be a part of your overall IT plan. We will then look at how to determine how much of a fit it really is and where to leverage it most effectively. The first step in the process is to analyze the server virtualization model with the goal of understanding why it doesn’t work for desktop virtualization.


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Lesson 1: Why the Server Virtualization Model Doesn’t Work for VDIVirtualization is a topic that just about every IT professional has had at least some basic exposure to at this point. Many businesses have adopted some form of virtual infrastructure, but this adoption is, at this time, mostly limited to server‐based virtualization. That isn’t to say that desktop virtualization is foreign, but it is emerging, and

as such you may have very limited exposure to it.

Server virtualization brought with it a host of justifications for projects, including server consolidation, decreased overall hardware costs, decreased support costs, simplified backup, and many others. Do these hold true for desktop virtualization? We’ll explore that answer as we compare server and desktop virtualization. Let’s start with the planning phase.

Planning I’ve seen a lot of server virtualization projects succeed even with the worst planning up front. The last server virtualization project I saw run into serious problems was the result of a complete lack of planning. Even that one was salvaged and showed an immediate return on investment. My personal experience has shown that desktop virtualization is less tolerant to planning missteps. This isn’t a bad thing per se.

Every IT project should be planned from the start, and desktop virtualization is no different. Building a plan that takes into account as many variables, goals, and metrics as possible makes the project that much more likely to succeed.

Desktop virtualization requires careful planning, testing, and piloting because it is so closely tied to end user experience. Users will not tolerate slowdowns or peripherals that don’t work. Remember that you aren’t delivering just a desktop in desktop virtualization. You are delivering a whole user experience.

Server virtualization gives more wiggle room, if you will, in the project. Taking a single physical server and repurposing it to support multiple virtual servers doesn’t require a complete restructuring of the network or additional hardware. Existing metrics for processor, memory, disk I/O, and such should already be in place on the physical server. These performance counters do a good job of showing approximate workloads for virtual servers over time. This data makes it relatively easy to pilot virtual server workloads. Desktops are different. Some users are more resource intensive than others and have less tolerance for slowdowns. In general, the task of finding out this information isn’t easy.

Licensing Licensing is also different. In many cases, server virtualization doesn’t require any additional operating system (OS) licensing. Most IT staff can rather quickly articulate what the Windows Server virtualization licensing rights are for the Standard, Enterprise, and Datacenter versions. The maturity of the server virtualization landscape has made this information widely known in the course of a few years.


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That said, I’m willing to bet that hardly as many readers will be able to explain without extensive research how many instances of Windows 7, for example, can be installed on a particular VDI platform and how many can legally be run concurrently. There are alternative licensing schemes designed specifically for virtual desktops. Finding out how much a virtual license costs and the legal rights associated with that license remains a difficult task. This is part of a normal growing pain process with any technology. Vendors like Microsoft have come up with several plans for desktop virtualization licensing, which are meant to simplify and keep costs down—however, these plans still aren’t fully fleshed out.

But before you can jump into licensing needs or even determining the key differences between end users’ needs, you need to get back to the goals of the project. Let’s start by analyzing the goals of desktop virtualization.

The Goals of Desktop Virtualization You’ve probably started down this VDI path with the belief that the goals of desktop virtualization are the same as those for server virtualization. Trying to start with a familiar knowledge base in server virtualization shouldn’t hurt a desktop virtualization project, should it? I think it might. Although some of the server virtualization goals apply directly to desktop virtualization, for most part, they don’t share the main business drivers. Understanding the differences is critical.

Server virtualization is largely focused on driving up efficiency and driving down costs. It tends to achieve these goals well. IT architects that take on server virtualization can draw models that show cost savings in a variety of ways:

• ver hardware Greater utilization of existing ser

• Space savings in the data center

• Reduced server maintenance costs

• costs Reduced power and cooling

• Software licensing savings

• yment time Reduced server deplo

• Application isolation

• Multiple platforms on the same hardware Desktop virtualization provides some of these benefits but not nearly as directly or in a manner that is as easy to quantify as server virtualization does. A desktop virtualization solution achieves a host of soft cost savings that requires a different analysis. These cost savings are going to be more difficult to quantify at the onset of the project than they are with server virtualization. It doesn’t mean they aren’t just as beneficial, but rather that they aren’t going to be immediately obvious.


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In particular, desktop virtualization reduces support costs associated with deployment and management of the PC infrastructure by streamlining the process of provisioning new “desktops,” deploying new applications, simplifying imaging because of uniform virtual hardware, and offering a longer refresh cycle for the existing physical desktop infrastructure.

Identifying How Users Interact with Desktops Is Critical Servers are back office products with which users don’t typically interact. Such is not the case for desktops. User experience is critical to the success or failure of a VDI project. And the goals of a desktop virtualization implementation should account for user expectations for performance and seamless access.

Do users perform separate roles when running on a physical desktop than on a virtual desktop? The answer is obviously no. Users aren’t all of the sudden using different applications or working with different data after a desktop virtualization implementation. Users are simply trading one form of service delivery for another form of service delivery. The applications and data that a user accesses will be no different whether interacted with directly on a physical piece of hardware (a traditional desktop) or delivered from a data center (a virtual desktop).

This user workspace concept will be important going forward because we are going to frame the use of VDI and other desktop and application virtualization efforts in this context. The concept of the user workspace is almost completely foreign to the server virtualization model. Why? The answer is a simple one: end users don’t interact with a server from an experience standpoint. The server is serving applications and data to the desktop, laptop, tablet, mobile device, or some other presentation method.

The most often cited reason for virtualizing desktops centers on the challenges and costs of managing PCs. Managing physical PCs is expensive and time consuming. The end user workspace environment can include tens to hundreds of various applications, all of which have their own supporting files, necessary dependencies, file conflicts, and so on. This results in conflict and a lack of standardization between desktops.

Lesson Learned So rather than attempt to build a desktop virtualization model with concepts borrowed from server virtualization, a better plan is to start with a new model from scratch. Doing so reduces the temptation to pull cost saving justifications, planning strategies, and benefit/goal analyses from server virtualization models. The following list highlights factors t model: that should be taken into account for a desktop virtualization cos

• costs (that is, more/faster servers) Basic infrastructure upgrade

• OS and application licensing

• ysical to virtual desktops Migration from ph

• End user training

• Physical and virtual desktop management costs


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You will find that these factors are difficult to quantify. How can you determine costs before you build a pilot and test? The trick is to start construction of a cost model that takes into account all of the factors you reasonably believe are going to affect the overall expense, build a proof of concept, then develop a pilot that is small enough to represent the desired goal. The results of the proof of concept and the following pilot will test the accuracy of the cost model and expose any weaknesses that can be corrected in the model before proceeding with a full‐scale project.

Lesson 2: How to Overcome Difficulties Supporting Distant and Offline Users Distant and offline users present one of the greatest technical challenges to the delivery of user workspaces using VDI. Much like server virtualization, desktop virtualization relies on a back‐end and appropriate connectivity to that back‐end to serve or present the workspace. This setup is fine as long as there is an appropriately robust mechanism for delivery of the user workspace end‐to‐end. Any level of latency, dropped connections, or general instability will seriously hamper the productivity of the end user.

We have already determined that the goal is end user service delivery. Interruptions to that delivery will critically impair the overall productivity of the user. These interruptions can result from many factors, such as problems with network reliability. To fully understand the challenges of service delivery to remote users and further down the spectrum, offline users, you have to look at the factors that affect both reliability and usability. Reliability influences whether you can deliver the service in a consistent manner. Usability is whether you can deliver it with a quality that won’t adversely impact the user’s productivity.

Reliability Let’s look at network reliability first. Every network connectivity technology is going to have varying levels of reliability. This doesn’t come from the technology used as much as the way it is implemented and how well it is supported. Speed also plays an important role.

Speed Network speed is crucial for a variety of reasons, and is more complex than just looking at the maximum theoretical speed of the connection. When you think about network speed, most often you think about bandwidth. However, bandwidth is only going to be part of the problem. Much more important is the latency introduced by the network. In a tightly controlled LAN, this isn’t going to be a big problem.

Gigabit Ethernet is a high‐bandwidth and low‐latency technology. As a result, it is ideal for service delivery and VDI. However, it is uncommon to have end‐to‐end Gigabit Ethernet to all users all over the planet. The reality is that we have to live with some levels of reduced bandwidth and latency. Desktop virtualization implementation must be conscious of the way users interact with the virtual desktop infrastructure—inside the LAN on Gigabit Ethernet or faster as well as outside the LAN where the network speed can be much less.


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Supporting Offline Users Offline users present a slightly different set of challenges than remote users do. An offline user is one that spends a lot of time with little or no connectivity. A good example is the field sales users that spend a vast majority of their time in airports and hotels. The offline user may be remote most of the time and have connection back to the data center for access to the VDI.

Traditionally, offline or remote users have made use of a solution to address connectivity interruptions and allow for productivity while disconnected. Technologies a decade old allow for offline files. Users have also had traditional hardware at their location that would keep resident copies of needed applications, associated settings, and preferences.

In the world of the virtual desktop, the desktop session or published application has been presented remotely to the end user. The challenges to accomplishing this with limited to no connectivity back to the data center are well known. Quite simply, if you can’t reach your data center, you can’t get your “desktop” or applications. In order to address this limited or no connectivity problem, vendors have created several unique solutions.

Supporting offline users can take the form of an offline desktop, essentially a local virtual copy of all the OS and application needs of the user. However, we still have to manage that desktop and the computer on which it runs. The technologies for delivering an offline desktop vary, but for the most part involve some sort of checkout and version control mechanism for the virtual desktop. This setup allows the user to work with a local copy of the desktop and synchronize the changes back to the data center as connectivity permits. The problem is that in order to have a seamless user workspace, the user must understand the processes associated with check‐ins, checkouts, version control, and synchronization. Each vendor will have slightly different process sets.

Reference Chapter 2 will examine the different types of access hardware that will greatly affect the user workspace presentation. New types of devices may not support offline desktop function and might be a clunky fit for VDI.

VDI’s technologies are challenged to meet end user service delivery goals when it comes to offline and remote users. The limitations imposed by required connectivity are too much to overcome for many businesses. Vendors have made measured strides to achieving success here; however, preserving a satisfactory user experience remains a challenge with VDI and this user class.


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Lesson 3: How to Support Heavy Users Heavy users represent a unique class of users. The heavy user typically is more tied to specialized hardware than the average knowledge worker. For example, an architect that relies on high‐resolution graphics and larger or multiple monitors will not be easily supported in a desktop virtualization scenario. I typically refer to this type of user as a power user, but because Windows has a built‐in user group also called “Power Users,” I’ve started referring to these users as heavy users. Really, the terms are interchangeable.

Technical solutions have evolved to help meet the increased demands that the power user places on a VDI system, but again you must focus on the reason for desktop virtualization in the first place and, more importantly, the service delivery aspect. Is the heavy user class one that should be a part of a desktop virtualization scenario or is this simply not the way to meet the goal of end user service delivery?

Let’s start this analysis by looking at the way the typical heavy user interacts with technology. Using this information, you can determine what or how much of that work fits with VDI and other virtualization efforts.

What does an example architectural or engineering heavy user employ in a traditional non‐virtualized desktop environment for service delivery? This user will have a CAD software package that has processor and memory demands that are greater than typical business productivity software packages. This software is needed in addition to other more common business applications such as office productivity, time tracking and billing, and various other supporting point solutions.

The second consideration is hardware. At the core, the processor, memory, and storage demands are higher for the heavy user than for the general business knowledge worker class of users. These demands are placed by the requirements of the specialized software packages themselves. These extra resources are expensive.

The costs per user that must be supported on the desktop virtualization platform will be higher for the heavy user than for the knowledge worker. Desktop virtualization solutions are starting to help with the specialized hardware and even now provide support for USB device redirection.

What are the criteria for when a heavy user can and cannot be supported in a virtual desktop o consider: ? Here are some of the factors t

• erals Directly connected periph

• Specialized input devices

• ort Multiple monitor supp

• Complex applications


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Heavy users often have requirements for 3D rendering and full motion video that are met quite well with physical desktops. The ability to offload these functions to a dedicated graphics system in a physical desktop is going to be easy and inexpensive, but this isn’t the case with a virtual desktop. Only recently, companies have begun to offer 3D and full motion support as part of the technologies to improve the visual capabilities of virtual desktops. There has been some level of support for 3D in many vendor offerings, but the most recent generation has allowed it to approach the experience that heavy users expect from a traditional desktop.

Microsoft calls this RemoteFX. It is a great start, but it has requirements for Windows 7 end‐to‐end, both on the client and on the virtual desktop. Also, the graphics processing on the server hosting the virtual desktop has to be increased in order to support the more intensive graphics display required from RemoteFX. Servers that have thus far been used to support only server virtualization may not work. These servers will have to have expansion abilities to take professional workstation‐level graphics cards.

Microsoft isn’t the only provider that is keenly aware of the rich user experience that virtual desktop users demand. Citrix has built the HDX protocol for use with their virtualization solution, which enables what they term as the “high definition” desktop virtualization user experience. If you are unable to support the end‐to‐end Windows 7 requirements or upgrade the server hardware to support these technologies, the user experience will diminish accordingly.

In addition, monitor spanning was introduced a few years ago to assist users with multiple monitors to have remote desktop sessions take advantage of more than one monitor. It does have limitations that the heavy user may not be able to live with. Maximum resolution is limited and not all virtual desktop platforms will support all of the available monitors.

The possibility that heavy users can be supported isn’t out of the question. However, you will have to address the factors mentioned to determine how to best support them. In doing so, you might find that the needs of your organization’s heavy users make virtual desktops unfeasible for them.

Lesson 4: Making Sure the Network Infrastructure Is Up to the Task The lynchpin in successful VDI delivery of user workspaces is its network infrastructure. In particular, network latency and reliability are paramount to success. So how do you determine the appropriate amount of bandwidth and thresholds for reliability?

One approach involves seeking the solution that fits best along the axes of good, fast, and cheap. As the adage goes, one can only expect the ability to prioritize two of these; however

entally important. finding the combination that meets your needs is fundam


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Network and infrastructure reliability are paramount, so consider the category of good to be a constant. Good means that the network connectivity and infrastructure are going to guarantee as much uptime as possible. In order to achieve this end, we are going to focus on two aspects, internal and external connectivity.

Understanding Internal Connectivity Needs Internal connectivity will encompass all interconnects and networking components such as switches and routers. Current LAN technology is mature when connecting internal hosts. Vendors and the industry in general already have inexpensive solutions for fault tolerance and redundancy. Entry barriers for providing highly reliable internal infrastructure are far fewer than they were even 5 years ago. This is welcome news for an IT architect that must balance budget constraints with the business goals of a highly available virtualization solution.

Any supporting network infrastructure must support Gigabit Ethernet at a minimum, and 10 Gigabit Ethernet is quickly becoming the new standard. This standard has evolved due to ever‐increasing network throughput creating areas of congestion in gigabit‐speed networks. That congestion is effectively eliminated with the upgrade to 10 Gigabit Ethernet. With good as a constant, fast and cheap are the variables that remain. Cheap can be accomplished with internal connectivity. 10 Gigabit Ethernet prices have dropped significantly, giving even limited budgets the ability to invest in core infrastructure at this speed.

Fast internal connectivity also isn’t much of an issue. It is nearly impossible to find anything slower than Gigabit Ethernet in the server space. Technologies inherent to servers allow for both load balancing and failover, which is great for getting a boost in speed and reliability, essentially combining fast and cheap in one package.

Tackling External Connectivity Problems Where the challenges become most evident is with external connectivity. Choices for Internet access are numerous. For the purpose of analysis, we are going to break down this concept into two categories: those with guaranteed service levels and those without. Certain technologies are more reliable and cost more. It isn’t that the second class of external connectivity is necessarily unreliable, but it is designed for speed over stability.

Internet connectivity to the remote users’ endpoint represents the most likely hindrance to productivity. This issue has become much more complicated as users access their workspaces over cellular‐enabled mobile devices. Are these users remote or offline? The answer depends on where they are, and the capabilities of the device, among a host of other factors.

Later, this book will discuss the types of devices and the emergence of new workspace access approaches that are pushing these limits. For now though, let’s establish that access can be on so‐called 3G and 4G networks, WiFi, WiMAX, or even legacy cellular networks. The IT architect will have to take into account all of these possibilities and set realistic expectations for the user experience for each of these types of networks and devices.


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Metrics for Ensuring Network Effectiveness What are the metrics that need to be monitored in order to ensure that the network infrastructure is up to the task? Internally, there should be metrics for total network utilization and per host/server utilization. Latency isn’t going to play an important role in the determination of adequate resources on a high‐speed network, but it will play a huge role in determining the adequacy of Internet connections. Externally, the metrics are much more important because they set the stage for both data center connectivity and remote user connectivity.

Employ a representative user during the pilot to determine the bandwidth requirements overall. The class of user won’t play much of a role in determining bandwidth requirements with the obvious exception of video and multimedia‐intensive users. The particular protocol used by the desktop virtualization solution handles screen updates and will affect the bandwidth more than the class of user.

For the purpose of determining bandwidth usage, let’s select a single access method at first and look at how different vendor protocols will affect the total bandwidth consumed per user. By access method, I mean desktop virtualization using protocols such as RDP and Citrix ICA instead of application virtualization. These will take more bandwidth than application virtualization in general. The reason is that the display of the entire desktop and the graphical interface associated with it is going to consume more bandwidth than the display of only a virtual application.

Incremental user experience optimizations have been added as well, such as protocol optimizations and compression algorithms that decrease the bandwidth required to display a virtual desktop. Virtual infrastructure vendors have varying‐level solutions to make the most out of limited bandwidth and the implication is that as time progresses this is going to improve the user experiences when running over low‐bandwidth links.

End users expect a virtual desktop experience that closely approximates the one they are used to with their physical desktops. Slowdowns in display of graphics and videos will not be acceptable. If bandwidth cannot be provided that will support these users’ expectations for display of video, users will complain about slowdowns and the entire project can be jeopardized. The importance of determining the representative user bandwidth requirements cannot be overemphasized. If these needs aren’t determined up front, the bandwidth costs can balloon, jeopardizing the entire project.

Once you establish the baseline requirement for a representative user, you can build a formula by multiplying the number of each that are expected to be concurrently accessing their workspaces by the requirements for each class that you have determined. Take this number and add a peak usage factor to compensate for spikes without a degradation of service. At the same time, factor in anticipated growth.


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Bandwidth requirements vary wildly, not just between classes of users but also depending on the way that you define a class of user and their particular role. Optimizations in the particular virtualization platform, compression technologies, and many other unknowns will affect bandwidth. Requirements as low as 20Kbps and as high as 180Kbps are not unreasonable.

Remember too that how you present the user workspace impacts the overall network requirements. Using existing technologies, this presentation can be an entire desktop or a series of presented virtual applications. Testing either scenario is critical to success. I alluded to it earlier, but there will be variation, however slight vendors might claim, in the different desktop virtualization solutions.

Once you have tackled the calculations for data center bandwidth and factored it into your costs, you need to turn to the more difficult calculation of the minimum requirements for the client side. As noted earlier, the client can be accessing the user workspace from anything ranging from a mobile device with limited bandwidth to a traditional thin client or even a full desktop.

Lesson 5: Preparing for Unforeseen Costs The cost models for server virtualization don’t translate exactly for desktop virtualization. We saw this in our earlier analysis. The reasons for this are many—as we have looked at already. Even the best‐planned project is going to be susceptible to some sort of cost overrun. Of course, the best way to ensure a successful budgeting for the project is to analyze as many factors as possible. Even then, there may be some that cannot be calculated with complete certainty. Let’s start with the known quantities that are shared between both virtual and physical infrastructure design, then look at the factors that are exclusively part of a desktop and, in many cases, a server virtualization build‐out.

If we start the cost model analysis with the factors that will be most comparable between physical and virtual desktops, the first item that comes to mind is the licensing costs associated with the OS and applications. Virtual desktop and virtual application software licensing hasn’t yet matured to the level that it has in the server virtualization arena. The answer to the question of how many copies of a particular desktop OS or application can be run virtually isn’t as easy to answer as the server question.

Hardware needs are certainly going to factor into the overall cost for the virtualization effort. It goes without saying that there are certain baseline needs for just about every form of virtualization technology. These include processor support for the platform at a minimum. Almost every server shipped in the past few years has the requirements for basic virtualization support, so there will be the drive to save costs by reusing and

’t be taken at face value. repurpose these resources. This is a great idea, but it can


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The ability to present user workspaces in a consistent manner will depend on the creation of a backend infrastructure that is seamless to the users working in it. Existing high‐availability technologies such as storage area networks (SANs), RAID arrays, redundant power supplies, and other technologies are going to be reusable when creating a desktop and application virtualization system. A single point of failure is going to interrupt the service delivery for more than a single desktop, so all design work has to focus on creating as reliable a system as possible within the allotted budget.

Most organizations are able to tolerate downtime for a single physical desktop system. Desktops are considered a commodity by many businesses. If one fails, it gets replaced and business continues. Things change up a little bit once we start virtualizing. A single server can handle several virtual desktops. The same principle may apply to a virtual desktop that does to a physical one, meaning that a single virtual desktop can fail without massive business interruption. However, you can’t have a server fail because it will lead to several virtual desktops being unavailable.

High availability comes at a cost. Swapping a commodity desktop containing an inexpensive hard drive for a virtual desktop that uses high‐end SAN storage is going to be several orders of magnitude more expensive. This additional cost will factor into the decision of reduced management costs versus increased infrastructure costs.

Perhaps the most difficult task is determining the specialized skills required to implement the project and support the solution going forward. An IT architect is going to have to understand the current technical landscape and anticipate the future needs of both the infrastructure as it will stand and any additional changes that might occur over the life of the infr factors that must be considered: astructure. The following list highlights

• The experience of the IT staff in general

• on technologies Previous staff experience with virtualizati

• Staff experience supporting remote users

• vendors Implementation and support offerings from

• Ability of the staff to embrace innovations

• Costs to outsource the project and support to a third party There will be more than this to consider, but all too often, the IT staff isn’t prepared to undertake a project of this magnitude without additional training, additional personnel, or third‐party assistance. Performing an initial analysis of the specialized skills required for

ate. various virtualization efforts will greatly assist in providing a cost model that is accur

The most important takeaway is that changing from physical to virtual desktops may require more upfront costs than you might expect. Planning carefully for those costs is crucial to avoiding overruns.


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Lesson 6: Making Sure the Reasons for the Project Are Well‐Defined Thus far, we have looked at cost models and how savings, while a part of the overall reason for a VDI project, are not the main business driver. Security is also an important factor but is secondary in many cases. When all factors are considered, the real reason for desktop virtualization is to obtain a greater level of consistent service delivery. That level of service delivery ties directly to the stated goal of providing users with a workspace that allows them to perform their job role regardless the how the workspace is accessed.

Previous experiences with server virtualization may lead seasoned virtualization veterans to gloss over the need to clearly define goals and scope. Even IT architects with limited server virtualization experience can fall into this trap. The wealth of information that surrounds server virtualization efforts may tempt you to simply adapt its goals and head blindly into a desktop virtualization effort. This method will certainly not address the appropriate delivery of user workspaces because its requirements are beyond those found in the server virtualization concept.

Vendor relationships are another potential pitfall. All too often, a vendor has a product, or even an entire solution, set to sell. Although these might meet goals and align with end user service delivery, every element of the VDI project must be critically analyzed against the well‐defined reasons for the project. All too often an executive reads an article that espouses the virtues of desktop virtualization. This leads them to believe that it alone will solve all of the problems of PC management and usher in a new era of productivity. Vendors are trusted partners but can sometimes be tempted to pounce on these opportunities a little too enthusiastically. Tempering vendor relationships will give you a more accurate idea of what can and cannot be delivered from a desktop virtualization solution.

Where Do Physical Desktops Fit? Reusing and repurposing physical desktops to support virtual desktops is a common approach. The first step to leveraging legacy desktops in a plan for future end user service delivery is to determine the remaining usable life for the desktops in use. If the focus is on creating effective user workspaces leveraging a virtualization solution, it doesn’t make much business sense to replace desktops and then relegate them to nothing more than serving up a desktop session hosted on a server.

Once you’ve determined that the desktop meets the requirements for delivery of a virtual desktop, it can be repurposed to do so. However, having to manage a physical desktop OS and then a virtual desktop OS greatly increases the support requirements for that desktop. The best solution is to set up the desktop as a thin client. Doing so reduces costs by allowing existing hardware to be reused.


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Vendors are starting to make great strides in the ability to repurpose physical desktops to become much more like traditional thin clients. The concept of the desktop as a thin client isn’t really anything new. Vendors have been building solutions for years to take advantage of terminal services by converting PCs into thin clients. Recently, Microsoft announced Microsoft Windows Thin PC (WinTPC). Essentially this is a smaller footprint, locked down version of Windows 7 that lets businesses reuse legacy desktops in a VDI deployment. It has a lot of advantages in security and deployment over reusing the same Windows OS desktop and provides a means for future transition to thin clients.

This sort of approach appears to be the trend because of the added flexibility and reduced costs. It also allows your organization to “roll back” to traditional desktops should the need arise. This software solution will prove popular over the next few years because of the ability to have a desktop or thin client as needed.

Summary There are a tremendous number of differences between server and desktop virtualization. The business drivers are different for each. The user experience is a major concern in desktop virtualization, but almost not at all in server virtualization. The nature of the users accessing the infrastructure is a large determinant in whether to virtualize desktops and, if so, how much to virtualize desktops. The cost savings come in through reduced support for desktop virtualization, more so than efficiency as in server virtualization.

You will need to navigate the current physical infrastructure that you have so that you can build a plan for what to reuse and what to remove. You will have to understand the challenges to service delivery and where the shortcomings in current technologies will impact those challenges. This isn’t something to take lightly—end user experience is critical to success.

The next chapter will explore how the landscape of desktop virtualization is evolving outside the traditional desktop as a means for accessing virtual desktops. We’ll also explore different service delivery methods and emerging technologies that will have to become a part of the plan for VDI. The cloud will be a key concern. There are many approaches to embracing the cloud to support desktop virtualization, and we will look at what works and what doesn’t. I want you to be able to anticipate how VDI is going to be a part of an emerging strategy for end user service delivery. Chapter 2 will provide critical insights in how to avoid pitfalls that will either require you to scrap VDI completely or won’t integrate your VDI well with future changes.


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Chapter 2: Smart Approaches for Merging Desktop Virtualization Today and Tomorrow

Although the promises of desktop virtualization both in terms of scalability and cost savings don’t always work the way they do with server virtualization, many of the technological similarities can allow solutions to serve double duty. The previous chapter looked at the key differentiators between server and desktop virtualization in general, including cost models and project justifications, problems with supporting different types of users, and the reasons for a desktop virtualization project in general.

The trend towards desktop virtualization, as a natural extension of the trend in server virtualization, shows no signs of slowing. Even if there are doubts about whether desktop virtualization is going to address all the needs of a business, it is certain that businesses are going to try to leverage desktop virtualization for at least some portion of the infrastructure. The challenge then becomes determining where to leverage and where not to, what to keep, what to reuse, and what to retire.

This chapter looks at which legacy solutions fit into virtual desktop service delivery and how to best use them. We will explore how the cloud is affecting the desktop virtualization trend. In addition, there is a whole series of emerging technologies that will make you rethink where and how to leverage virtual desktops. Based on this information, you’ll be able to determine where desktop virtualization best fits into a service delivery model.

To have a successful IT strategy, a business must look at not only what exists currently but also what is emerging. A smart business has to understand what has taken the market by storm and how it has become an embedded part of the IT landscape. Desktop virtualization is going to be affected by trends not just related to virtualization but technology in general. Lesson 1 will assist in determining how legacy solutions will fit in overall goals of service delivery, from hardware to management software and even support processes.


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Lesson 1: How Legacy Solutions Integrate Into Service Delivery When I talk about legacy, I don’t want there to be any confusion as to what I mean. In the realm of desktop virtualization, I’m speaking about technologies that are typically used either in the server space exclusively or have not traditionally been a part of a desktop service discussion.

It may seem a little odd that I’m referring to legacy solutions as part of a virtual desktop discussion, but the fact is, almost no one is going to be able to rip out all of their existing infrastructure just to start from scratch with VDI. Honestly, why would any business decide that it is appropriate to redesign everything just to support an emerging technology? That technology would have to be so revolutionary and give that business such a competitive edge that there would be no other option than to adopt it completely and suddenly. Desktop virtualization isn’t that type of technology.

Chapter 1 established that VDI wasn’t the final destination but merely a part of a transformative journey that improves the end user experience and enables IT to more cost‐effectively support users’ needs. With that focus, consider the following questions for your business:

• If we are going to have VDI in some form, what do we do about all of the legacy desktops that are still in production?

• What about the servers and networking equipment in the data center and corporate offices?

• What about the management platforms and software we use to support it all? What do we do with it? Do we reuse it? Do we repurpose it?

You should reuse and repurpose as much of it as possible. This makes natural sense, as we all have to work within limited budgets. Then how do you determine what you can reuse and repurpose?

Take Inventory Let’s start by taking an inventory of the current business infrastructure. We need to determine which components can be reused and which have to be replaced. In addition to hardware, this inventory process will necessarily include software and even support processes too.

Hardware is a good place to start with the inventory process. You already know the requirements for virtualization platforms in general. This is one area where the differences between server and desktop virtualization aren’t all that varied. I struggle to think of a server that has shipped in the past few years that doesn’t fully support the technologies required for virtualization.


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From a server hardware standpoint, if your servers are capable of supporting a virtual server infrastructure, they are going to be capable of supporting a VDI. Vendors don’t sell different servers for each purpose. These servers are just as good for virtual workloads as they are for physical ones. It doesn’t matter whether those workloads are virtual server or virtual desktop in nature.

Hardware support for virtualization has been around for several years. Although this hardware support has matured and brought speed and scalability gains, there is one key difference between now and when server virtualization started to become mainstream. When server virtualization started to come into the forefront of IT strategies, servers didn’t always support hardware‐accelerated virtualization. Virtualization platforms required direct hardware support for their hypervisors that many servers could not provide. As a result, only the most current generation of servers at that time were viable candidates for becoming virtual hosts.

Fast forward 5 years and we see that all servers currently shipping feature some form of hardware virtualization support. The newer the server, the better the support will be with technologies that allow much more efficient direct access to hardware resources. Nonetheless, all servers in the past few generations will have the required support for desktop virtualization efforts. To move a physical server from a server virtualization role to a desktop virtualization role, not much is required. Certainly, the hardware does not have to be replaced, creating the first chance to reuse infrastructure components.

In the first chapter, I identified the importance of creating an effective pilot to determine performance needs and ensure that any solution will fit the users’ expectations for usability. Being able to employ servers that still meet the requirements for virtualization but might be aging to the point where they are targeted for replacement will be a great way to test desktop virtualization without adding new servers. To complete this step, take an inventory of all of your servers and indicate which include hardware virtualization support.

Analyze Supporting Components and Processes Let’s move from the server hardware itself to the other supporting components in the data center. In this area, upgrades that were performed to support server virtualization projects will translate into real‐world use with desktop virtualization. There are no special requirements for networking hardware or storage systems to support desktop virtualization. You can leverage all the switches, routers, power distribution, and such that you’ve already put in place without additional cost.

With that being said, there is a caveat to reusing all of the supporting components without planning for any upgrades. Implementing VDI can be a massive tax on the existing network infrastructure. Being able to reuse a good portion of the networking infrastructure doesn’t mean that networking infrastructure upgrades and optimization won’t need to occur. An entire industry of specialized networking equipment designed just for desktop virtualization scenarios has emerged.


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Let’s turn our attention to support. At this point, you will have supporting software that is used for desktop and server support. You also have management and support processes and methodologies that will have to be analyzed. Because the desktop operating systems (OSs) are the same regardless of whether they are on a physical desktop or presented virtually, you can leverage all your existing investments in your management software platforms.

You would think that support processes and methodologies wouldn’t change appreciably either; however, support changes are one of the primary drivers in going to desktop virtualization. The support team will still have to respond to hardware problems occurring with a virtual desktop, such as failures with the desktops or thin clients that are accessing the virtual desktops. The team responding to that will have a different set of diagnostic and repair steps to perform than they would with legacy solution support.

Looking at how much can be reused, it seems that this VDI transition is pretty much a slam dunk, right? Not so fast! There are some problems. In order to understand what these problems are, let’s step back a minute and look at traditional desktop hardware. Business desktops aren’t designed with high availability in mind. They typically don’t have redundant hard drives. They don’t have redundant power supplies and data center‐class components. They are designed to be cost effective and border on being commodities.

It may be fine that these business desktops don’t typically include redundancy features. When a new PC can be imaged and put in place when a critical component fails, that downtime affects only a single user. It isn’t acceptable when that critical component fails on a server that must support 10, 20, 50, or more virtual desktops. That type of outage would critically affect a business and illustrates the problem: VDI takes all of our resources for multiple desktops and puts them into a single point of failure.

One of the tricks I’ve found in creating successful VDI projects is to determine how much exposure the failure of a single component will cause in terms of downtime and lost productivity to all the virtual desktops that rely on that component. It sounds simple enough, but it really isn’t. To better illustrate this point, let’s use an example where you decide that you want to put your company’s accounting department of 20 users onto virtual desktops. Here is how it looks in the physical desktop world in terms of cost and supportability:

Each user gets a PC. The cost of each of these accounting PCs is $1000 and there are two spares of the same type and cost. The total cost of this physical desktop infrastructure is $22,000. When a user PC fails, the IT support team images a spare with all the standard applications and customizations that the user needs and replaces the PC for the user. This image, deployment, and setup process takes about 1.5 hours. A failure affects one user only. The failure of a single user isn’t critical because there is more than one of each type of user and the department continues to operate while this single user is down.


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Now let’s take a look at this scenario through a post‐VDI implementation lens:

To make your accounting VDI rollout as cost effective as possible while supporting all 20 users, you put all the accounting users on a single server using shared storage. This server has some redundant components such as power supplies and hard drives so that it can continue to operate with the loss of one component here and there. The cost of the base server is $6000 with the memory and processor required to support the workload of all 20 users. The cost of the shared storage, almost certainly from a SAN, is the wildcard here, but can be $50,000 or more.

I understand that these numbers are somewhat difficult to quantify exactly. The costs of server components are generally going to be more expensive than those of a desktop even before any kind of redundancy is added to the equation.

This rough approximation of the two technology approaches reveals that you will get roughly the same results; however, VDI, because of reliance on high‐availability hardware and SAN storage, is going to be much more expensive. The nature of the shared resources in the virtualization route means that the failure of a critical component will hinder productivity for everyone, not just a single user. In a pilot, this may be acceptable, but it certainly won’t be in a production environment.

Adapting Server Solutions to Desktop Virtualization One of the most common ways to improve the reliability of a virtual infrastructure is to implement high availability in the form of a SAN and clustering. Neither of these high‐availability solutions is new, but their use in supporting a desktop infrastructure is. Clustering and SANs are common for servers; a natural extension of that is for use with server virtualization. However, it is a slightly different paradigm for VDI. These technologies will bring the needed reliability and scalability to desktop virtualization but not without costs.

SAN storage is considerably more expensive than direct attached storage (DAS) primarily because of the redundancy and scalability that is part of the SAN package. The move to VDI means you are trading inexpensive disk space on a single physical desktop for expensive virtual desktop space on a SAN simply because so many virtual desktops rely on the shared storage.

Technologies like thin provisioning allow you to save a considerable amount of disk space up front by allowing the virtual desktop disk usage to start with only the minimum requirements and grow as needed (as with server virtualization). However, the concern still exists that the nature of a virtual desktop will consume a fair amount of space on the SAN.


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Remember that the goal is end user service delivery. You are creating a user workspace so that the user can perform their particular job role. Virtual desktops aren’t the only means to do so. There are alternatives such as application virtualization where the application is encapsulated and isolated from the OS. These virtual applications can be deployed to users without the extra support requirements of an entire virtual desktop.

Wouldn’t it be much more cost effective to use application virtualization instead of simply giving users a complete desktop? Certainly there would still need to be the investment in redundancy, but the storage costs would be far less. Letting the users have their own physical desktop but giving them on‐demand access to applications has other advantages that are outside the scope of this guide. It is important to note that application virtualization is a technology that can fit better than VDI for many uses. In addition, application virtualization works well in a VDI, so these two virtualization technologies can happily coexist.

How Management Solutions Fit Your business is going to have an array of software that is used to manage and maintain your physical desktop infrastructure, including security software, patch management solutions, and troubleshooting and diagnostic tools among other point solutions. Most of this is going to be reusable with one caveat. The nature of VDI as a shared infrastructure means that you are going to want to minimize the impact on users from actions like virus scans and patch deployments. These can rob performance from individual desktops and that effect is going to be magnified on a shared VDI. There are vendor recommendations that antivirus solutions not even be run on top of VDI instances. Likewise, a best practice is

es. to patch only VDI virtual machine parent images rather than the individual instanc

Many vendors include some form of management toolset for their virtual desktop management platform—partly to ease the cost burdens of buying additional third‐party components for patch management. You might choose to leverage the vendor‐supplied management framework, but I recommend that you test your existing management solutions to assess impact. If there is no impact or the impact is negligible, you can re‐evaluate the ROI of your management solution at subscription or support renewal time.

Lesson 2: How the Cloud Affects Service Delivery to Users We just looked at what it would take to build a VDI in a private data center, but what about the buzz about the emergence of the cloud as a home for VDI? Can desktops be hosted in the cloud and still be a part of a VDI rollout? How does this fit with service delivery?

There is a natural temptation to leverage a cloud service for hosted desktops, as cloud‐based solutions are maturing rapidly and vendors have put a lot of effort into figuring out how to support VDI challenges such as scalability on demand. Thus, the cloud computing service provider has put the investment into designing and testing the solution; a private

ford to develop a VDI from scratch. company with budget constraints might not be able to af


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Investing in a VDI has been a barrier to adoption for many businesses. As discussed in Chapter 1, there are several costs that might not be obvious from the onset ranging from infrastructure upgrades to software licensing. Using hosted desktops in the cloud will replace the in‐house backend server and infrastructure needs of a VDI but won’t address the client, or access side, of the equation. There will still have to be some sort of means of accessing the virtual desktops, whether via a physical desktop, thin client, or some other device like a tablet. Turning to the cloud for a hosted VDI solution will only affect the hardware capital expenditures for the data center‐side of the equation. There will still be the costs for the desktops or thin clients that will be used to access the hosted VDI.

In a hosted‐desktop setup, bandwidth and latency are still going to be important factors in the overall end user experience. Ideally, a provider that offers a cloud‐based solution for hosted virtual desktops will have a well‐developed means for analyzing and allocating bandwidth for access to ensure that the presentation will be as indistinguishable as possible from a local VDI. The provider should also have a means for supporting users with low latency access at multiple locations around the globe. The problem is that no such service exists. Supporting geographically‐distributed users will require planning to make sure that bandwidth and latency problems don’t adversely affect users. No hosted VDI vendor can accommodate these needs for seamlessness.

Perhaps the most difficult challenge to overcome with a cloud‐hosted VDI solution is access to server‐based resources. The earlier discussion assumed that the data center that was going to be hosting the virtual desktops was also the same one that had the file servers, email servers, application servers, and so on. In that scenario, the access to server resources would be very fast and the problems with bandwidth and latency virtually disappear.

Going to a cloud‐hosted VDI introduces a big problem: Your users working on the LAN leave the network to go out to the cloud to access virtual desktops which in turn come back to the LAN to access server resources. This “in and out” network traffic is going to seriously impact the user experience because of the increased latency and reduced bandwidth. It could possibly expose your network to security problems inherent with opening inbound and outbound access to these resources. Additionally, it places increased demand on the speed and reliability of Internet access. One can appreciate the irony of having perfectly good desktops on the LAN and perfectly good servers on the LAN, neither of which can “talk” because there is no Internet access to the virtual desktops hosted in the cloud.

Where the cloud‐based VDI solution makes sense is in the limited demands of a particular class of user. Let’s use an example to see where this works: Your company has a large sales team that accesses a single application for customer management and order entry. This desktop image is standardized and highly locked down. The application does not access any data on your network but instead accesses a third‐party, Internet‐based provider such as SalesForce.com.


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This scenario best illustrates a fit for cloud‐hosted VDI. Keep in mind that the more basic the functions that need to be performed and the less the volume of data that must be transferred, the better the cloud VDI solution works. So this begs the question, How is this better than a physical desktop with a locked down configuration? For many businesses, the answer is that it’s not really better. Where a fit exists is for field‐based personnel that are outside of the typical management reach of the business or are accessing the virtual desktop from personal systems but still needs a locked‐down desktop for their role.

Once again we run into limitations with where resources are located based on how much network speed is available and how reliable it is. Costs for Internet access have been decreasing, but not as quickly as VDI technology adoption has been increasing. This is perhaps why so much effort has gone into the development of protocol optimizations by virtualization vendors. The smallest increases are still critical to providing acceptable user experiences. Virtually all major vendors have made great strides in reducing protocol overhead, but this isn’t going to be a panacea to the problems associated with accessing remote resources over slow or high latency links.

The cloud does have a role in VDI, but for many businesses, that role is limited at best. Until cloud service providers can effectively tackle the responsiveness issues that are going to be critical to service delivery, the role of the cloud will be for very specific workers and roles.

Lesson 3: Technologies We Never Saw Coming Thus far we have been looking exclusively at a Windows desktop served virtually to a physical desktop. This is almost certainly going to be a large portion of the enterprise VDI adoption. What was unexpected is the emergence of a whole host of different form factor devices that users have gravitated to. This wasn’t a concern with server virtualization because the presentation of resources to users didn’t really come into play. However, in a VDI, the way the user interacts is critical to service delivery.

Two years ago, server virtualization was already mature and desktop virtualization was coming into its own. However, no one was quite sure how the forms of access to virtual desktops were really going to take shape. At that time, Android was just a glimmer in the eye of a Google developer. The iPad didn’t exist. The iPhone, Blackberry, and Windows Mobile phones were primarily collaborative devices. Things have rapidly changed. Apple’s iOS took the world by storm as part of a successful tablet and phone family of products with a wide array of applications. Android came to power a variety of devices including phones and tablets. Microsoft introduced a whole new mobile OS and announced major plans for tablet functionality in the next major release of Windows. How does this all fit together in the context of desktop virtualization and service delivery?

One of the first technologies to emerge in the business world that wasn’t designed for the business world was the iPhone and the resulting iPhone OS and later iOS. Users that had these phones for personal use almost immediately demanded that businesses support them. Apple responded by building in more business‐oriented support, including support for Microsoft Exchange Server. The resulting explosion of iPhone adoption lead vendors to develop additional applications for business needs.


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Tablets flooded onto the scene with the introduction of the iPad. Although tablet form factor PCs have been on the market for almost a decade, the iPad propelled the true tablet form factor into the mainstream. The iPad was able to capitalize on the success of the iPhone and the inroads that had been made with application development for the iPhone.

s. The result is a unified ecosystem and a desire for service delivery on these new platform

Not long after the success of the iPhone, Google introduced a competitive OS in Android. Android similarly serves as the platform for a whole host of devices including smartphones and tablets. Android uses a similar application purchase and installation method to the one that Apple uses with the iPhone and iPad’s underlying iOS. Likewise, rumor has it that Microsoft has spent considerable energy in developing a unified tablet and smartphone OS. Both the Google and Microsoft offerings have further pushed the desire for users to be able to work anywhere at any time with the same access to data and applications that they have inside their corporate networks.

This discussion will treat these OSs the same and these devices as a single class of devices. We aren’t concerned with who created them so much as with the impact they have had as a

. whole on the ability for users to work outside of a traditional Windows PC environment

With regard to desktop virtualization, the widespread adoption of these devices wasn’t predicted simply because they were the first time we saw mobile devices that weren’t PCs that brought high‐resolution screens with always‐on Internet access over cellular networks, support for LAN connectivity via WiFi, and application support for access to virtual desktops. The functions that these devices can perform were previously the exclusive domain of laptops—and not just laptops but rather laptops with some sort of always‐on network access. Laptops with always‐on networking are not as common as these new smartphone and tablet devices that ship with WiFi and 3G or faster Internet access. Additionally, these smartphones and tablets have considerably longer battery life than their laptop equivalents.

Having always‐on network access is critical to virtual desktop delivery in the traditional VDI sense. Once these devices emerged with this capability, it was only a matter of time before someone saw the potential for service delivery. The major desktop virtualization vendors immediately began making versions of applications to access both their desktop and application virtualization solutions.

This is great news for the most part, but there is a catch: now there is a whole class of devices that has to be supported and secured. IT departments began having problems immediately with just providing support for secure email and contact management.

rn. Providing secure access to corporate networks for desktop access became a real conce

These devices started out as consumer devices and weren’t designed to be securely or centrally managed like desktops or thin clients. Mobile device management tools have always been behind the curve compared with desktop and server management solutions.

part of the VDI ecosystem. Regardless, the reality is that these devices are becoming


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The problem that the user needs to have uninterrupted service if they are realistically going to be able to access a virtual desktop with a smartphone or tablet. Unless the smartphones and tablets are connected to the LAN at your corporate office, there can be no guarantee that the user experience will be acceptable, much less preferred. But users are endeared to these devices because of their travelability, which means virtual desktop access is going to be over a cellular network or external WiFi network. This level of reliability and speed won’t consistently meet service delivery goals.

A potentially better solution is to have a mechanism for secure application delivery instead of delivery of an entire virtual desktop. Regardless of whether this application delivery takes traditional or virtual application forms, this setup will allow the user a better means of working outside the corporate LAN. Traditional VDI simply isn’t the best fit for this type of device and use case. So then where does a traditional VDI fit?

Lesson 4: Finding a Home for Traditional VDI Let’s take a small step back and look at desktop virtualization in the most basic form and see where it best fits. We previously examined the requirements for a successful VDI. The biggest challenge is often providing end‐to‐end connectivity that is suitable for the experience that the end user is expecting. We also saw that providing virtual desktops becomes more difficult with remote and offline users because of the nature of how a desktop is accessed.

The end‐to‐end connectivity is affected by speed, in the form of total bandwidth/latency and reliability. To provide a VDI, this problem must be addressed. So where are both speed and reliability the highest? Earlier, we isolated this to the LAN, but it is more complex than that. Here we are looking for the ideal conditions to use traditional VDI—you don’t want any kind of connectivity issues to impact how you deliver a virtual desktop. To ensure ideal conditions, you must also consider the device being used to access the virtual desktop and what sort of LAN connectivity it should use.

Leveraging existing desktops for the purpose of accessing your VDI is going to be the most common means for several reasons, including reducing hardware replacement costs. Being able to take existing physical desktops and either convert them into some form of thin client or using them as they are with RDP, ICA, or some other protocol will keep costs down on the hardware front. However, this “double desktop” scenario increases costs in management. Which one of these methods for accessing virtual desktops is going to be the best fit?

Many companies are going to be sensitive to reducing the cost of supporting a physical desktop. Even if it is converted to act like a thin client, there will be some sort of support needed to keep it running. This could be in the form of hardware support or management of the underlying software used. The level of support depends on the way the physical desktop is converted. There are several solutions out there that will accomplish the thin client conversion goal. Each has a set of benefits that will make it attractive.


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The products that sit on top of Windows will still require patch management and security software. This will have to factor into the ongoing management costs. One very big positive is that there won’t be problems with drivers and peripheral support for the existing hardware. Products that replace Windows will tend to reduce the security vulnerabilities because these are usually stripped down, having a small footprint and reduced attack surface. This small footprint even allows some of the thin client OSs to be loaded fresh at each boot and can even run diskless.

Existing management tools and methodologies are going to make the physical desktop as an access method for a virtual desktop the quickest to get up and running. Often this requires nothing more than a client connection. Conversely, security and ease of ongoing support may make the reinstallation of physical desktops as thin clients the most attractive means to provide virtual desktops. There needs to be a thorough analysis of the needs of the organization in order to determine whether using the desktop as an access method or as a thin client will work best.

Not all customers will choose to leverage the existing desktops in a thin client manner. Many will choose to continue to use physical desktops for their current purpose and retire them as they fail. Retired desktops will then be replaced by “real” thin clients. These vendor‐supported thin clients will require upfront capital expense to purchase and deploy, but offer benefits in security and supportability from the vendors themselves.

The current generation of thin clients also offer support for the rich multimedia presentation technologies provided by the latest desktop virtualization platforms and provide offloading of some of the tasks that would otherwise be intensive on the servers hosting the virtual desktops. Some of these thin clients are even referred to as “zero clients” where there is no setup ahead of deployment. All you need to do is unbox, connect cables, power on, and go. The thin client detects the virtual desktop server and gets everything it needs to allow the user to login and start being productive.

Going the thin client route will eliminate a large portion of the support costs related to desktop hardware support. A business just needs to keep enough spare thin clients so that a failed thin client can be replaced in the field with a minimal amount of downtime. Thin clients for use with VDI offers a number of benefits: The appliance‐like reliability of thin client hardware makes them inexpensive to support and maintain. The proprietary, stripped‐down OS makes them very secure, and the capital expenditure is typically less up front than a traditional desktop, although the savings are realized in the reduced total cost of ownership.

The thin client in general has also proven itself to be a tried and true technology for use with terminal services and Citrix over the past decade plus. Using a thin client solution for VDI is a natural extension. Because of the static nature of a thin client, meaning it is just going to sit in a fixed location like a desk, it is going to have fast, always‐on LAN connectivity. Thus, it addresses the key concerns for end user service delivery with a virtual desktop. Also, the modern thin client and, more important, the transport protocol used, has support for peripherals over USB.


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Although repurposing desktops as thin clients is an attractive mechanism to save on some of the capital expenditures of transitioning to a VDI, there is still a phased path to migration away from those legacy desktops in the long run to “true” thin clients. This type of LAN‐connected, fast and highly reliable connection for basic productivity users makes it the ideal place for traditional VDI. Now let’s take a look at what doesn’t work as well with VDI.

Lesson 5: When It Doesn’t Fit, Cut It Out A lot of this guide has been dedicated to reusing as much infrastructure as possible. The current economic conditions have stretched budgets farther than just about any time in modern IT history, so it is going to be difficult to say that something doesn’t fit and has to be removed and replaced. The good news is that it doesn’t have to be all at once. Using a phased removal process may work perfectly well for many infrastructure components, particularly existing physical desktops.

The first step is to determine the criteria for what does and does not work. Earlier we examined how existing desktops can be repurposed to serve either as thin clients or leveraged in a hybrid approach where there is still the core OS in use but also virtual desktop access from the desktop platform. With some exceptions, these desktops will make an effective part of a transition to a VDI. The exceptions are desktops that either do not meet the requirements to run the software you select to convert them to thin clients or are too old to remain in service. You may have a policy in place that mandates retirement of desktops based on age or particular specifications for which these desktops no longer fit. It is tempting to keep these desktops around, but the near commodity nature of desktops and reduced costs of thin clients may not make this the best option.

Networking infrastructure is the next main area that must be examined. The first chapter spent time discussing the merits of high bandwidth and low latency to the overall user experience. Again anything that can be used to increase speed and decrease latency in the network connectivity should be implemented if within the budget. At a minimum, Gigabit Ethernet end to end is required, and realistically 10 Gigabit Ethernet is going to be required at the core for the servers hosting the virtual desktops and communicating between each other and backend storage. Peripherals such as printers and specialized input devices must all be scrutinized. Although the majority of businesses are going to have shared printing, you’d be amazed how much printer sprawl I see. I’ve encountered many businesses where there are as many printers as there are employees. This is a terrible waste of efficiency and costs a fortune to support and supply. Once you have determined the route you will use to have users access their virtual desktops, you must test all of these peripherals and be prepared to retire those that don’t work. Don’t be afraid to use this time to correct the printer sprawl in your organization. You can even use this correction as part of the cost justification of transitioning to a VDI. The important takeaway point here is that you must

vily invested in. be prepared to remove items that have already been hea


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Now comes the trickiest part to figure out: the virtualization platform itself and the management tools. You may have invested heavily in a server virtualization platform and corresponding set of management tools only to find out that those really don’t work exactly the same when applied to desktop virtualization. This is OK. As we have already seen, the management challenges are different for virtual desktops than they are for virtual servers. Don’t feel like you need to extend your virtual server platform and management tools to the VDI. There are specific management tools that will work best for each scenario.

There is good news here overall. As we have already seen, VDI isn’t a perfect fit for all scenarios, so the impact of removing parts of the infrastructure that don’t fit isn’t going to be something done all at once. Using a phased approach to removal can be just as important to success of the project as a phased introduction of new equipment.

What’s Next By taking a look at what you can keep and what you must change, this chapter expanded upon Chapter 1’s foundation of how to use VDI and where there will be hidden challenges. In addition, it is important to step back and take a look at where the industry in general is trending so that any investments in a VDI are reusable.

This chapter determined that existing desktops can be a powerful part of a VDI used either as they are for access to a virtual desktop or repurposed as dedicated thin clients. We took a look at the cloud to examine whether it will be a realistic part of your virtual desktop future. We analyzed technologies that were never expected to be a part of desktop virtualization, focusing the discussion around service delivery. We even tried to find the best home for traditional VDI and learned how to identify where to avoid the temptation to keep components that aren’t going to be a great fit for your virtual desktop strategy.

The next chapter will tie it all together. So far, we’ve looked at VDI and service delivery from a high‐level overview, which was meant to help you determine if and how much VDI is going to be a part of your business. Chapter 3 explores what works well together and how you can fit what you have into what you want and where you expect to be with desktop virtualization. This chapter also starts to look into the near future for solutions that don’t yet exist but that you might need to capitalize on any investment in VDI. Most importantly, we will determine what metrics are required to decide whether you made the right

n investment. investments at the right times to maximize your return o


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Chapter 3: Integrating Legacy and Emerging Technologies into IT Service Delivery

Any business will have some holdover legacy technology to support even in a completely revamped service delivery‐based virtual infrastructure. Integrating the legacy components in as complete a way as possible will help limit the costs associated with the project overall. Businesses must be sensitive to carrying forward only the right items and understanding where the infrastructure will have to be overhauled to support desktop virtualization.

Trying to integrate technologies and solutions just for the sake of reuse can lead to greatly increased costs, particularly in terms of support, which is what desktop virtualization is meant to reduce. Embracing the end user service delivery goal will require a thorough understanding of how these legacy and emerging technologies fit to allow the most cost‐effective means for building evolving service delivery models.

The first chapter looked at the goal of end user service delivery and how desktop virtualization helped to meet that goal. To do so required a step back in thinking to evaluate how users interact with their desktops and then apply this knowledge to effectively leverage desktop virtualization. As part of that journey, we were able to determine where desktop virtualization didn’t fit particularly well. This critical recognition then shaped the conversation surrounding desktop virtualization. Instead of looking at desktop virtualization as a destination in service delivery, we were able to see it as a piece of an evolving service delivery strategy.

The second chapter reviewed the legacy components that are already a part of most network infrastructures and explored where to place them in a desktop virtualization model. This important step made sure that any new infrastructure met the goals without unnecessarily making new purchases or attempting to fit components into a VDI build out that weren’t right for the project. The emergence of the cloud, with all of the buzz surrounding it, as a possible part of the desktop virtualization and service delivery discussion meant that we had to take into account this new paradigm and the possibilities of hosted VDI.

Along the way, we saw that some of the promises of hosted VDI need technologies that don’t yet exist. This chapter will take a forward look so that you can see where solutions like hosted VDI will make sense. Additionally, we are going to see what critical technologies are needed in order for desktop virtualization to become a larger part of a service delivery strategy.


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This chapter will build upon the lessons learned in the first two chapters to determine how to build a successful VDI that meets the goals of end user service delivery without overreaching as a solution. We are going to apply the lessons learned earlier to allow us to best leverage desktop virtualization as part of a continually developing series of service delivery methods.

One of the keys to desktop virtualization is to understand the limits of technology now while anticipating what is coming in the near future. The market is constantly changing as vendors see how businesses want to leverage desktop virtualization and then help adapt the technologies to work where they haven’t quite been a good fit yet. This chapter will explore where natural progressions in technologies will enable greater use of desktop virtualization.

This chapter will conclude with a solid explanation of what can be done now to maximize an investment in desktop virtualization and what to expect in the near future. This understanding will provide a means to determine whether desktop virtualization is the right service delivery technology for your organization—or will be as the technologies underpinning it mature.

Lesson 1: Finding the Right Ingredients to Make It Work At this point, you have been able to review existing solutions in both virtual and physical infrastructures. When we began this journey, we started with a comparison of server virtualization and desktop virtualization. This seemed natural because the lessons learned with server virtualization were thought to translate to desktop virtualization in the same ways. We found out quickly that such wasn’t the case. The end user experience that means so much to the success of desktop virtualization was the critical difference.

We next looked at how virtual desktops and physical desktops fit into service delivery and what this meant for your organization. Transitioning from physical desktops to virtual ones had a theoretical payoff in terms of reduced total cost of ownership and support. However, depending on the means in which the transition occurred (that is, virtual desktop access from a physical desktop, thin clients, and so on), the returns on investment and how well an organization could meet the reduced support costs goals varied wildly.

Towards the end of the second chapter, we investigated how physical desktops fit into the equation. What do you do with all of the legacy desktops that you have? This question creates a big problem for IT architects when trying to determine what solutions from the

l infrastructure. physical infrastructure can be used to support the virtua


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Let’s take a look at the options for addressing perhaps the most prevalent legacy component in the transition to a virtual desktop infrastructure: the physical desktop. There are three options available with regard to physical desktops in a virtual environment:

• Use the Windows desktop as it is to support dual duty as both a Windows PC for specific needs and a means for accessing virtual desktops for certain needs

• Replace the physical desktops with a device that is purposely built for access to virtual infrastructure access (that is, a thin client)

• Use a solution that “converts” the Windows PC into a device for accessing virtual desktops; essentially this turns that PC into a thin client

Each of these options carries inherent consequences. The focus is to balance the competing goals of reduced total cost of ownership/support with reduced capital expenditures.

Option 1: Dual Duty Desktops The first option really requires no additional capital expenditures for desktop replacement. Here you only have to use a software solution to access the virtual desktops. In the case of RDP, there is nothing to install, just start accessing virtual desktops immediately. Installing clients for other virtualization technologies is a matter of seconds per machine. This really is the simplest way to integrate legacy technology into a desktop virtualization plan.

There is one major drawback, though, to this first option. You now have a “double desktop” scenario. You have to support the physical desktop and the virtual desktop. This setup clashes with the reduced support cost goal of desktop virtualization. In fact, the single largest driver of desktop virtualization is reducing the support costs for the desktop infrastructure, and this method arguably increases those costs. For this reason, the “double desktop” option should be used with caution.

Option 2: Replacement with Thin Clients The second option requires the most up‐front capital to be expended but essentially reduces the cost of supporting a physical device to near zero. Thin clients have been around for a long time and have proven to be a great mechanism for delivery of service. However, they aren’t free. Although thin clients do, in general, cost less than their desktop counterparts, they are often as expensive as a desktop depending on the features needed.

Option 3: Desktops as Thin Clients The third option is one that has tremendous flexibility but has seemed to miss widespread adoption. There are several vendors that have created solutions that replace the operating system (OS) on PCs with a stripped down one designed to perform the same hardened, maintenance‐free function as a thin client. The obvious plus is that there is no need to purchase additional hardware.


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Take note that this solution isn’t quite as simple as it may seem. One of the major benefits of thin clients or physical desktops is that the OS is designed to support the hardware in the best possible or most flexible manner. On physical desktops, this comes in the form of extensive hardware driver support. On thin clients, this comes in the form of specialized hardware and software built to work together. When you try to “convert” a desktop into a thin client, you might run into problems with hardware compatibility and vendor support. Success is completely dependent on testing and selecting a solution that supports your entire desktop infrastructure.

Using desktops as thin clients is a means to embrace virtual desktops now with reduced support costs for the access device because it isn’t serving in a traditional desktop sense. Earlier chapters explained how vendors have built solutions, such as Microsoft’s ThinPC, to perform this function with the same goal of leveraging desktops in a thin client‐like manner until thin clients can replace the desktops. This signals a serious acknowledgement that the industry realizes the growing problem of the transitional period from physical desktops to thin clients.

Choosing the Right Option for Physical Desktops in a Virtual Environment Using desktops in a dual desktop role—where the physical and virtual desktops are both running full OSs and application sets as needed—hasn’t aligned well with the reduced support costs goal of desktop virtualization. Although this option might be great for testing purposes, it isn’t the most cost‐effective way to achieve a production virtual desktop infrastructure.

I also don’t recommend a wholesale shift to thin clients as a replacement for desktops unless the desktops are to be replaced already and the choice can now be made to replace them with thin clients. Thin clients certainly make sense for reduced support and power consumption. This is the final destination for replacement of legacy desktops that we should strive for, but the capital expenditure makes this hard to justify in the context of reduced operating costs. If the infrastructure is set for a desktop hardware refresh, this option is ideal for maximum return on investment.

Being able to “convert” desktops into thin clients buys businesses time to get the maximum life out of existing legacy desktops without having to expend massive amounts up front to embrace desktop virtualization. This solution, as noted before, isn’t perfect. Some hardware may not work in this role due to hardware incompatibilities. Nonetheless, it does fit a wide variety of hardware with minimal costs. There are certainly costs to transition to the use of legacy desktops in this manner, including labor to install and test, but this cost is far less than hardware replacement.


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What About Supporting Infrastructure Components? Desktops are going to arguably be the largest single legacy component to consider when figuring out how to integrate what you have into what you need to support VDI. However, there are a whole host of other components that need to be taken into account. The first two chapters investigated the networking and storage requirements for VDI.

The required investment in additional upgrades to your network infrastructure in order to meet the user experience requirements of VDI are going to vary depending on where you are in a technology refresh cycle, much like desktop replacement. VDI requires constant connections to virtual desktops, so investments made in load balancers, redundant switches, and in general for redundant components will be reusable. Also, making the upgrade to 10 Gigabit Ethernet will significantly improve performance as well as the efficacy in network aggregation, a tactic that becomes useful in managing VDI’s dense networking arrangements.

Storage requirements, as discussed in the preceding chapter, are going to change as well. VDI relies upon fast and reliable storage. This generally means SAN storage. For many companies that have invested already in a scalable SAN solution that also provides for upgrades to faster interconnect technologies, VDI’s storage requirements aren’t going to be a problem. Earlier iSCSI SANs are going to be taxed heavily by the increased load that desktop virtualization places on the shared storage.

Application Virtualization and Supporting Technologies Application virtualization is a key supporting technology set that can get lost in the discussion of desktop virtualization. Being able to separate the applications from the OS is going to be critical to the rapid deployment of applications in a cost‐effective manner. Later, we will explore this in further detail; the key takeaway from this lesson is that much of the other technologies will at least in the near term find some use in a VDI environment.

Lesson 2: Integrating the Old and the New into Something CoherenEarlier lessons worked to best balance what and how much of your legacy solutions to bring forward. Putting that all together here is going to be critical. As long as the focus remains on end user service delivery, you are going to be fine. Previously, the focus was on what you should keep in order to keep the infrastructure build‐out costs as low as possible. In this lesson, we aren’t going to focus on what we integrate now, but what makes sense as part of a long‐term evolution in service delivery.

t

a


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Shared Storage Needs As part of a long‐term strategy, perhaps the most important component to service delivery with regard to legacy solutions is shared storage. Shared storage, particularly SAN storage, will always play a critical role in the delivery of service. This was the case even before server virtualization, when having centrally managed storage was critical to effective storage utilization and enterprise scalability. It caught on for clustering and high availability and made a natural fit for server virtualization shortly thereafter. SAN storage is the key enabler in a scalable desktop virtualization solution as well. The SAN solution that is used with desktop virtualization will have a tremendous demand placed on it in terms of both disk performance and overall storage requirements.

When planning for the future growth and performance with shared storage, it is critical to implement a solution that can be upgraded to allow for faster disk and interface technologies. As the demands placed on the SAN increase, there will be a need to eliminate those as bottlenecks. Faster interconnect technologies will enable many more virtual machines to use the same SAN for their needs. Disk performance is a key factor as well. Adding more and faster disk spindles facilitates this improved performance. New technologies that integrate very high‐speed solid state drives to facilitate caching may also play a role, particularly as their cost diminishes.

Networks and Supporting Technologies Shared storage is just part of the puzzle. Although the networking equipment that is currently in place to support both physical and virtual networks will work well, the demands of desktop virtualization will require upgrades in speed. The good news is that a transition can occur. The iSCSI wave brought with it a new era of interoperability that should continue for the foreseeable future. This good news means that additional infrastructure equipment can be added to increase speed without having to do a complete replacement.

Fibre Channel hasn’t made this the most cost‐effective path. Avoid making purchases that have proprietary technologies that may not be supported in the next 5 years. That said, the evolving technologies associated with Fibre Channel over Ethernet (FCoE) offer a transitional mechanism to move off current Fibre Channel SAN storage. They facilitate the administrative ease associated with iSCSI but atop existing copper cabling and network interface cards.

Challenges to Integration Integration has been well discussed and how to bring legacy and emerging technologies into something coherent and cost effective has also been an important part of this lesson. However, many new technologies are going to emerge that will bring challenges to integration as often as they will solve them. Understanding where to invest now to avoid obsolescence will require planning.


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Lesson 3: The Technologies We Are Waiting For It is time to start looking forward so that you can effectively plan for how desktop virtualization will change as technologies adapt. We have well discussed that desktop virtualization doesn’t fit all scenarios. It isn’t going to be a panacea for the problems of end user service delivery. This isn’t because the concept of desktop virtualization is flawed. Far from it—we know that desktop virtualization is a great step towards improved service delivery. This guide has shown that VDI fits scenarios such as LAN‐based access very well. The biggest problem is that the technologies required to make desktop virtualization fit a much larger set of use cases don’t yet exist.

Improvements to Connectivity Required for Hosted VDI In the previous chapter, I talked about hosted VDI, which provides a great example of a service delivery model that is waiting for technology to catch up with the concept. There are many emerging vendor solutions that are beginning to capitalize on creating a cloud‐based solution for desktop virtualization. This seems all well and good, but we have already

y. determined that bandwidth and latency requirements are critical to service deliver

Failing to deliver enough bandwidth with low levels of latency will result in a user experience that is going to seriously hinder end user productivity. How do you control the bandwidth and latency for users from all types of access devices, on all types of networks, from various locations who are trying to access a hosted VDI while having an experience that meets their expectations? That question is loaded with variables that any cloud‐based VDI solution is going to have to address.

In Chapter 2, I made it clear that any hosted VDI provider is going to need to know where a user is connecting from and ensure that the user is connected to the lowest latency, typically geographically closest, cloud facility—and based on the service level requirements, provide a near‐LAN quality experience. Right now, this can’t be done with certainty. There need to be massive increases in Internet connection speeds and a reduction in the price of that Internet connectivity in order to realize this goal.

This challenge doesn’t just affect hosted VDI from vendors. Building your own private cloud infrastructure is going to have the same challenges. The larger and more distributed your user base, the more difficult it will be to provide consistent experiences using virtual desktops. You have to be able to provide bandwidth on demand to the nearest data center. he technology set required for this undertaking is something we have to wait for. T


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The Required Evolution of Mobile Data Networks and Devices The increasing use of smartphones and tablet PCs as a means for accessing virtual desktops will introduce new challenges to connectivity that networks don’t well address with the current technology infrastructure. Although there are emerging 4G and WiMAX broadband networks, the maturity and reliability of these infrastructures and the ability of devices to support them aren’t yet to a level that guarantees service delivery. Without these technologies further evolving and becoming much more robust, the access to VDI from them is going to remain a “best effort” scenario in which consistent service delivery is highly dependent on device, location, other users, and a whole host of variables that cannot be controlled.

The possibility of using offline virtual desktops is one that has come about to help address the issues with offline or highly mobile users that have less than ideal connectivity. However, these solutions don’t support all platforms, and virtual desktops consume a large amount of local storage when used in this scenario. This might work for a mobile user with a laptop, but those with a smartphone or tablet are not going to be able to get the experience they expect due to processing and storage limitations on the devices.

Thin Client Limitations Thin clients are a fantastic means of accessing virtual desktops, particularly in the LAN environment. However, they aren’t going to fit all end user scenarios. In the first chapter, I outlined the challenges with heavy users and VDI. Thin clients as a virtual desktop presentation solution are great for standard users, but specialized peripheral support and multiple monitor support are still lacking. Unlike a PC that can be upgraded to support newer or faster interconnects, like USB 3.0 or eSATA, a thin client is limited in upgradability. Multiple monitor support is something that several vendors provide, but upgrading a thin client to support additional monitors isn’t going to be an easy task. Support for more than two monitors is almost impossible to come by. There are some quad‐monitor supported thin clients, but these are far from being mainstream and have large price tags.

Increased Storage Demands Storage performance and costs are going to continue to be a major factor in limiting adoption of desktop virtualization. As previous chapters discussed, the trade from local inexpensive storage on desktops to shared and much more expensive SAN storage is going to be a necessary part of any VDI transition. The problem is that a smaller company isn’t

age one. necessarily going to have a SAN and/or the talent to man


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Shared storage is going to have to come down in price to a point where the differential between desktop storage and shared storage is far less than it is today. A company that wants to dramatically increase the number of virtual desktops that it can provide is not going to be able to do so without massive capital expenditures. SAN vendors’ reliance on proprietary hard drives instead of commodity hardware means that upgrades and interoperability are a huge problem. SAN solutions will have to become further standardized and modular to provide companies with greater flexibility in VDI storage options. This isn’t to say that this is true of all SAN vendors. There are some that offer modularized solutions to increase interoperability.

Management solutions for shared storage are also going to have to become much easier to work with. It has only been very recently that major storage vendors have realized the need to provide simple‐to‐manage entry‐level offerings for shared storage. SAN management will need to get to a point where an IT generalist can easily provision storage and provide onsite service to the shared storage array.

Enhanced Network Management Solutions As VDI solutions mature and continue to achieve widespread adoption, management solutions must keep pace. There are a whole host of point solutions that exist to help with management, but a unified toolset that is capable of monitoring and managing all of the critical infrastructure components isn’t as simple as an off‐the‐shelf purchase.

The increased demands of VDI on a network infrastructure require that many more aspects of the network infrastructure are managed in order to ensure effective service levels. In the previous chapters, we looked at what upgrades need to be made to the network infrastructure to support VDI. Let’s turn our attention to how to determine whether you are able to manage those demands and understand the stresses placed on the infrastructure as well as how to determine whether you have met those demands.

I’m not saying that the existing management solutions can’t provide crucial metrics to assist with isolating bottlenecks and determining where upgrades must be made. I’m positing that management solutions are general in nature and aren’t designed specifically with desktop virtualization and end user service delivery through VDI in mind. Vendors need to create simplified management solutions that allow network teams to adapt quickly to the changes in demands that VDI places on the network and to ensure that virtual desktop service expectations are met. VDI vendors offer many of the requirements for management, but these aren’t yet mature. Third‐party solution providers that specialize in this area have built great management solutions for the physical desktop space and should xtend and expand these solutions so that management can occur within a single pane. e


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Expanding VDI Adoption These technology enhancements that we are waiting for are going to be critical to expanding VDI adoption. The areas of storage, network infrastructure management, external connectivity, mobile devices, and overall usability of the solutions are going to need to see technology enhancements in order to increase the adoption of desktop virtualization. Without these enhancements, smaller businesses face a steep set of challenges in implementing any form of VDI, and larger businesses face scalability and management challenges with their desktop virtualization endeavors. The overall costs will also need to come down as the technical solutions evolve in order to allow a wider array of businesses to justify the costs of building a VDI versus the savings in support and ongoing management.

Lesson 4: How to Determine You Got It Right Determining where your investments in desktop virtualization as a service delivery model have been successful will require a period of analysis. During this time, the pre‐VDI support costs will be compared with those in a post‐VDI implementation. The cost benefits of desktop virtualization rely on a reduction in the total cost of ownership of the infrastructure. The first chapter examined how critical it is to understand the benefits of desktop virtualization and have realistic expectations of the best uses for desktop virtualization.

Understanding the goals of a desktop virtualization project is crucial to success. Likewise, the planning and execution phases are critical to success. So how do you determine that you are undertaking a desktop virtualization project with the proper understanding of what you can expect to accomplish and how to quantify that success? How do you determine that you got it right?

You need to compare the desktop virtualization solution that you have built with the legacy infrastructure it is replacing. There are several problems that threaten to make this comparison impossible. Gathering accurate user feedback, having appropriate pre‐VDI metrics on support incidents and responses, and support issues previously unseen prior to the VDI implementation are all going to make this task difficult.

Gathering Intelligence from Users During the pilot phase and even into a limited production VDI build out, users are going to be a key source of information on the success of the VDI implementation. Creating the user workspace in a manner that is equal to or greater than the users’ current expectations was part of the original goals we outlined. Desktop virtualization is about end user service delivery. You must gather intelligence from the user base that will allow you to accurately

than what they had before. measure whether the users think that the VDI is “better”


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This will be a problem. The nature of surveying users makes the objective determination of success difficult. At one end of the spectrum, there will be users who may be uncomfortable with the change and will perceive the change as a diminished experience. At the other end of the spectrum, there will be users that are either excited to work with the new technology or believe that the transition to this new solution will fix other unrelated problems. These users may incorrectly report increased service levels. Other user may see an increase or a decrease in the quality of their end user experience but may not report that accurately for a number of reasons such as unfamiliarity with the way VDI works or limited use of the new VDI that doesn’t let them accurately describe their experience.

The biggest problem you are going to face with user feedback is that you are trying to compare objective costs for support before and after the use of desktop virtualization by relying on subjective user input. There will be a good core of user feedback that does help in determining whether you have succeeded in your VDI goals.

Review Pre‐VDI Support Metrics Establishing a baseline of support metrics must be done prior to any VDI pilot. I can’t emphasize this enough. Although gathering and categorizing support metrics is something that should be a part of all business IT directives, we know in reality that this doesn’t always happen like it should. If there is no way to determine the root cause of support issues prior to implementing a desktop virtualization project, there will be no way to determine whether the support issues that desktop virtualization is meant to reduce have actually decreased.

Part of gathering these metrics in pre‐VDI and post‐VDI environments is isolating what support metrics are meant to be reduced by VDI. Up until now, we have focused on the generalized reduction in support costs through desktop virtualization. Now we need to look more granularly at support incidents and isolate which types of support incidents are going to be reduced, eliminated, and resolved more quickly through the use of desktop virtualization. Even if you are gathering pre‐VDI support metrics, those must be of the type that can be analyzed in the context of what desktop virtualization can achieve.

One of the best ways to establish appropriate metrics is to build categories that reflect the different types of incidents that can occur in general with support. The following work well to start:

• m Problem Operating Syste

• Driver Conflict

• Problem Application Crash/

• ure Hardware Fail

• User Training

• Software Installation


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Many incidents in these categories should be virtually eliminated with desktop virtualization (that is, driver conflict and hardware failure). Others will decrease under VDI, such as OS problems and software installation and application crash/problems. Some, as they are outside of the desktop environment either physical or virtual, will stay at the same rate or may even increase (for example, user training).

The support categories I have provided are by no means exhaustive. These serve as an example of commonly encountered support issue types and how they vary wildly in the way that desktop virtualization affects them. Determining appropriate support metrics with the most appropriate types of incidents for your environment will help ensure that results can be accurately measured.

What About New Support Challenges? What do you do about new types of support that might be introduced by the transition to desktop virtualization? Most of the new support incidents that come from the VDI environment should now be server related. You have moved the desktop to the data center and hosted the virtual desktops on servers now. Maintenance and support issues for the desktops that typically fell to the desktop technician level now are going to happen at the server technician level in the data center. You have to make sure that any possible increase in data center server support costs are factored into the cost equation.

Another challenge is determining the severity and impact of a hardware or infrastructure support issue. As we discussed in previous chapters, the shared nature of VDI, particularly the shared storage on SAN, will mean that downtime and failure of a data center component is going to impact a much larger segment of the user base. Here again, planning and understanding the implications for support with VDI will mean that this metric can be estimated up front—although it can truly only be determined upon failure.

Determining how you got it right means asking the right questions about what types of support you expect to reduce or eliminate and understanding that the metrics you gather may not be as accurate as you want. Being able to understand the support costs for failures you have not yet experienced will also be critical to determining whether your VDI investment paid the dividends you are expecting.

Lesson 5: What the Future Holds Determining what the future holds for desktop virtualization is a difficult proposition. We have established that the purpose of undertaking a desktop virtualization transition is to provide service delivery through a mechanism that offers reduced support costs and

desktops. reduced total cost of ownership over traditional physical


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We know that desktop virtualization is not a fit for all current physical desktop user scenarios. The earlier proposed technological changes will expand the adoption of VDI, but is it really going to be the final solution to the problem of end user service delivery? The first chapter introduced the concept of end user workspaces. To most end users, the workspace concept is tied to what they see on their desktops. It is a collection of icons, applications, documents, and user‐specific customizations that enable a user to work in a manner that is most conducive to their needs. For this reason, desktop virtualization will continue to grow; it provides a mechanism for workspace delivery as a consistent desktop experience.

The reduced support costs and increased reliability of computing in a data center will also make desktop virtualization an attractive proposition to businesses of all sizes. This is particularly true as businesses go through the next one or two desktop refresh cycles. These refresh cycles will allow the most cost‐effective times for either partial or wholesale transition to desktop virtualization. During these PC refresh periods, at minimum, we should expect that a good portion of LAN‐based users will prove to be the best candidates for virtual desktops. These LAN‐based users will have the best chance of seamless virtual desktop experiences most closely approximating their physical desktop experiences. The task worker that doesn’t have any specialized peripheral support needs or complex processing and graphics requirements is going to be the most cost‐effective type to move to a virtual desktop.

Vendor solutions now allow rich multimedia and 3D support for display of virtual desktops. The demand for this as a part of virtual desktops is going to increase as more users clamor for an experience that is similar to the physical desktop they are used to. This idea illustrates how, in the next few years, the way user workspaces are delivered will change.

Problems for Widespread VDI Use Widespread desktop virtualization adoption is going to be most dependent on the availability of cost‐effective and high‐performance storage as well as networking reliability and performance enhancements. Over the next 2 to 5 years, those two categories will need to ramp up to keep pace with the demand.

Storage has been the key problem with effective widespread VDI implementation. Storage costs are continually dropping and shared storage solutions are becoming much more affordable for small and midsize businesses. Still, the substantial price per gigabyte of storage differential between SAN and traditional desktop storage is far from parity. A major cost shift is going to have to occur similar to the one that did in backup with regard to disk versus tape costs. Similarly, the way virtual desktops are stored and the high level of uplication that occurs is going to have to be addressed. d


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Focusing on Service Delivery Desktop virtualization isn’t the only way to deliver services to end users. Application virtualization is showing strong growth as a technology set in and of itself. Combining application virtualization with desktop virtualization allows for further decreased support costs.

When you break down the end user experience to its components on a traditional physical desktop th three categories: , you end up wi

• The desktop OS

• The applications that the user needs

• The data/settings/customizations that the user requires A virtual desktop is going to have the requirements of all three categories. One might say this is necessary for the sake of end user experience and familiarity with working in this way. However, being able to isolate these component categories will allow IT architects to have future flexibility.

The desktop OS is really nothing more than a platform upon which a user interacts with the applications and data they need to perform their specific job function. Being able to provide the user with a workspace that marries the desktop OS with the applications and with the data/settings while being able to separate them will bring a much higher level of supportability to the desktop ecosystem. Encapsulating applications using virtualization is a critical step to making this vision a reality.

Delivering applications is one of the biggest challenges faced by IT personnel. The use of application virtualization along with user storage that isn’t local to the virtual desktop will enable the virtual desktop to be a generalized OS that fades into the background. However, this idea isn’t exactly working in practice as well as it does in theory. This focus on delivering applications, data, and the user state instead of the desktop allows you to uncouple the desktop and enables more flexible alternative delivery methods.

Implementing VDI Now with a Future Mindset We have explored the best use cases of VDI employing existing technologies. We have also determined that VDI is certainly going to be a part of emerging service delivery models because it helps reduce support costs and drives down total cost of ownership in the long term. Nonetheless, we need to remember that desktop virtualization isn’t a fit for all uses and all users. PC refresh cycles, required storage upgrades, and the number of remote and

VDI plays in service delivery. offline users all factor into where and how much of a role


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Make sure that the investments made today in desktop virtualization have clearly defined goals and are measurable. Being able to understand the limitations of VDI and where those limitations are going to likely be removed in the near future will help you understand the best means to future‐proof your investment in VDI. VDI is going to at some point transition

es. into a service delivery technology that addresses virtually all of the current challeng

What does this mean to your business? Plan for VDI and don’t be afraid to make an investment in desktop virtualization. There are many areas in which it makes great business sense to do so, but do be aware that having expectations of desktop virtualization as the end all, be all of service delivery is going to lead to missing goals due to unrealistic expectations. As long as the models you develop and the reasons for the transition to VDI are understood and foremost in all decisions, then VDI will make a powerful part of a omplete end user service delivery solution. c

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