The decision to use application and desktop virtualization is only the first step in the larger process of storing and delivering virtual desktops and applications.
The advantages of virtualization may seem obvious; it can improve mobility by delivering desktops to remote users, reduce hardware costs by allowing IT to give users thin clients in place of full-featured PCs and more. To maximize these benefits, however, IT has to decide on virtualization factors such as how to host and deliver virtual applications, whether its users need persistent or nonpersistent desktops and more. IT pros can easily overlook the potential issues of application and desktop virtualization, such as training IT for the new desktop and app management process and compatibility concerns.
If IT can make the right decisions, then it can maximize the advantages of virtualization. Each decision requires that IT understands its organization's cost constraints, user needs and IT pro capabilities.
The first and likely most important decision that IT must make regarding application and desktop virtualization is where to host the desktops and apps. IT must decide when to host virtual desktops and apps itself -- VDI -- and when it should rely on a service provider to deliver desktop as a service (DaaS).
IT must understand that VDI vs. DaaS is not purely black and white. Many organizations host virtual desktops in-house but also rely on DaaS in other situations. DaaS is particularly useful when the number of virtual desktop users in the organization fluctuate because it is very easy to scale up or down. IT can pay for the exact number of desktops it needs at a given time. With VDI, IT must make the adjustments itself on the back end.
The VDI vs. DaaS debate is one-sided in terms of upfront cost because VDI requires IT to build its own back-end infrastructure to host the virtual desktops and applications. For small to medium organizations that don't have the capital to invest in their own hosting infrastructure, DaaS may be the best option. With DaaS, IT pros won't have to spend time monitoring the desktops, configuring Group Policy Objects, and other VDI management duties because the DaaS provider handles all of it for them.
There are several important benefits of desktop virtualization that VDI offers and DaaS does not. For example, VDI provides more security and direct control over the desktop and app configurations, maintenance, delivery and more. VDI does have the major upfront cost of building the back-end infrastructure, but once IT builds VDI the organization avoids the subscription fees that DaaS providers charge.
Considering VDI vs. DaaS ultimately comes down to the needs of any given organization. VDI is a major commitment, but organizations that can afford the cost of building it should consider this option. If an organization can't afford to build VDI or isn't committed to building its own infrastructure, then DaaS is the answer for them.
One of the major benefits of application and desktop virtualization is simplifying management. VDI makes it easier for IT to monitor, configure and troubleshoot all of its desktops, and DaaS takes away the burden of management entirely. But IT must decide how much it wants to sacrifice the end-user experience to simplify management by choosing between nonpersistent and persistent desktop virtualization.
Nonpersistent virtual desktops don't maintain any user settings or files from session to session, which can greatly reduce the amount of storage IT requires. This may, however, cause issues with the end-user experience; generally speaking, users prefer to maintain customizations and files from session to session. The storage savings are so significant, however, that if IT can get away with choosing nonpersistent desktops it should.
Persistent virtual desktops provide the session-to-session customizations that users likely prefer, but this option comes at the cost of a massive increase in storage. Where IT can store nonpersistent virtual desktops as a single golden image with all of the desktops and apps included, IT must store persistent desktops individually to preserve the user settings and files. This drastically adds to the storage capacity IT needs for the desktops.
Many of the benefits of virtual desktops are present for both persistent and nonpersistent desktops. IT must consider the needs of users and how much storage it can afford when deciding between nonpersistent and persistent virtual desktops.
If IT opts to host its desktops on VDI, it must consider which hypervisor technology to invest in. With the proper hypervisor technology, IT can simplify its management process, ease desktop scalability and take full advantage of application and desktop virtualization.
When IT decides between hypervisor options, it must consider compatibility and potential hidden costs that increase the total cost of ownership (TCO).
Hypervisor technology that is compatible with the current desktops and infrastructure is essential. For organizations that run Windows desktops, compatibility is not usually a problem because the most popular hypervisors -- VMware ESX, Linux KVM, Microsoft Hyper-V and Citrix XenServer -- all work with Windows. All of these hypervisors, with the exception of Hyper-V, can host non-Windows OSes as well. IT must also pay attention to the nuanced VDI hardware requirements that each hypervisor needs before selecting one of these options.
TCO can be challenging for IT to calculate because many of the costs of a hypervisor are beneath the surface. Training costs for IT and labor costs vary across the different hypervisor technology options. Licensing can also significantly increase the TCO -- the most notable example of this is VMware's ESX.
Perhaps the most important role of a hypervisor is to ensure each user has the necessary virtual resources to run his desktop effectively. Hypervisors offer different features to prevent loss of user productivity. KVM, for example, offers hot-plugging, which involves adding additional back-end components without shutting down the VDI.
When IT deploys virtual desktops, it also can take advantage of virtual app deployment, including simplified management and ease of updating, upgrading and patching applications. Application virtualization can help IT by giving it more control over application permissions. Sometimes IT stores the applications as part of the central desktop image to deliver all virtual components at once, but this is not the only option.
IT can use application layering, which stores and delivers virtual apps separately from the desktops they run on. This allows IT to alter the application's image without touching the golden desktop image and users to interact with apps as though they were native.
If application layering isn't ideal, IT can deliver Published applications, which it installs and stores on the back-end infrastructure and delivers in a bundle or individually. With this process known as application remoting, users can interact with the applications natively.
IT can simplify its virtual app deployment and management with these methods, but ultimately it must factor in the organization's infrastructure, user needs and more to come to the right decision.
IT can use thin clients as end-user devices to cut hardware costs with VDI. If an organization uses virtual desktops and applications, it can most likely use thin clients for end users because the server provides the virtual resources that a PC would normally provide for a desktop.
IT must decide which of the many thin client options, including Raspberry Pi, Dell Wyse and Google Chromebook, is the best fit for its organization.
The thin client options on the market today are more feature-rich than ever before, but the goal is still to minimize cost with limited features. There are thin client options for the most cash-strapped organizations and for those that require graphics processing.
Organizations seeking minimal upfront cost should consider Raspberry Pi, which is available in its most stripped-down version for $40 per device. The Google Chromebook is a high-end option that ranges from $150 to $400, depending on the functionality IT requires. Though the upfront cost of the devices is much higher, IT's management burden is lower with the Chromebook because it handles patching, security audits and software inventory on its own. Dell Wyse has numerous models ranging from $200 up to more than $500 with a range of features IT can choose from, including processing, storage and more.
