Desktop virtualization is a technical implementation that enables a system to emulate other systems using only software. As hardware capabilities have continued to improve far beyond software requirements, virtualization has become the next frontier for performance improvements and optimizations. The result is that virtualization is now standard for any organization seeking to maximize its information technology impact.
How Does Desktop Virtualization Work?
There are various implementations to desktop virtualization that use slightly different approaches, though the fundamentals are generally the same. Essentially, a virtualization platform running on a server manages instances of a software-based computer that users connect to and use as their workstations.
The essential components of desktop virtualization are:
Hypervisor: Also called a virtualization manager, the hypervisor is the framework that assigns and manages resources used by virtual desktop environments.
Host and guest systems: The host system is the hardware used to manage virtual machines, while the guest refers to those machines.
Connection broker: This component controls the connection and authentication between end users, the host server and their guest desktop.
When a host server is set up for desktop virtualization, the guest systems use the host's physical resources, including disk space, memory, processing power and network connectivity. In doing so, the guests produce a virtual hardware profile that other operating systems can use.
After a user connects to a network to access their desktop, a virtual machine is functionally no different than if the user were sitting at a physical computer. There are a few different ways to implement desktop virtualization, depending on the needs of the organization:
Local desktop virtualization: Local desktop virtualization refers to the practice of running the virtualization stack on a system that the hypervisor can physically access. For example, if you want to use software that only works on a specific operating system, but you don't want to install that operating system, you can create a virtualized instance of the required platform.
Remote desktop virtualization: This implementation refers to the practice of running a desktop instance from a remote server. This allows users to access an environment remotely via a network connection and a client running on a computer or tablet.
Application virtualization: This approach entails setting up an application in isolation rather than running it in a desktop environment. When users connect to the application, they can access its functionality, but the app can't access the underlying operating system or other hardware resources.
Layering: Layering is another method of virtualizing a single application. Instead of being isolated from the operating system, layering involves running an instance of an application on a virtual disk that's mounted when a user connects. This provides a rich application experience while reducing any impacts on the server when the app isn't in use.
User virtualization: This refers to the storage and maintenance of the user's data and settings on a remote server instead of the user's system. This architecture is sometimes grouped with remote desktop virtualization. Since end users access a full desktop, they use a virtualized user profile. Organizations can also implement user virtualization for local systems to improve security and the user experience.
While these methods describe the results of each architectural implementation, there are different ways to deploy the underlying virtualization technology. Each virtual desktop type is suited to different requirements and scenarios.
What Are the Types of Desktop Virtualization?
Regardless of the type of implementation used, virtualized desktops are functionally identical. But in the back end, differences vary across resource usage, costs and licensing considerations.
Virtual Desktop Infrastructure (VDI)
Virtual Desktop Infrastructure, or VDI, describes the implementation of a dedicated virtualization stack, such as VMware's ESXi or Microsoft's Windows Server Hyper-V. These platforms run on a server in an organization's data centers and manage resources and connections for virtualized systems. Known as hypervisors, these virtualization managers run "close to the metal," so any impact caused by an additional layer between the server hardware and the user software is minimized.
Remote Desktop Services (RDS)
Most IT teams are familiar with Microsoft's Remote Desktop Services, or RDS. With RDS and the Remote Desktop Protocol, organizations can enable remote access to desktop images and applications provisioned on internal servers. As opposed to an actual virtualization model, RDS is a session-based approach that allows users to access desktops via "thin" clients, effectively accomplishing the same approach. Since RDP is built into most enterprise IT solutions, using RDS as a virtualization solution reduces complexity.
Desktop-as-a-Service, or DaaS, is a cloud-based approach to virtualization. Like other cloud services, DaaS solutions are hosted on external servers that users connect to for a desktop environment. Using a DaaS provider for virtualization provides the same benefits as other cloud services, like increased flexibility, decreased complexity and more effective resource management.
What Are the Benefits of Desktop Virtualization?
There is considerable variance across the different types and architectures of desktop virtualization, so it's worth exploring each to find a solution that maximizes the benefits. Desktop virtualization can provide the following improvements:
Simplified desktop administration: By managing desktop environments from servers located within company data centers, IT teams significantly lower administration concerns, including maintenance, upgrades, backup management and security.
Easier support: By transferring a significant amount of complexity to a server environment, teams can provide better support to every user. Accessing a remote virtual machine is like streaming a movie, so differences in hardware configurations, personal device implications and other wildcard variables are less impactful.
Lower costs: Depending on the implementation, virtualization can provide modest to immense cost savings. By using low-cost, low-power clients and putting the bulk of processing onto remote servers, companies drastically improve compute efficiency. Instead of resources being spread across hundreds of users, they're distributed intelligently — and only when the user is connected.
Better security: Many security concerns associated with user devices are effectively mitigated by using desktop virtualization. With strong policies in place, users can access their environment securely from the device they choose with no security implications.
Choosing the right deployment model can amplify the advantages of desktop virtualization and potentially provide other benefits, depending on the organization's needs.
How to Choose a Deployment Model
Some factors that determine the suitable deployment model include the software an organization is considering for virtualization, compliance requirements, existing infrastructure and budgetary constraints.
For example, the VDI model often poses the highest initial cost, with administration of these setups also requiring specialists. A VDI setup offers the highest level of control and significant performance advantages. It's also the most flexible in terms of platform and software integration.
With Microsoft's RDS, organizations can't provide a Windows 10 desktop experience. Since the tooling required to provide an RDS experience runs on Windows Server, end users are effectively using a desktop experience on a server environment. For smaller organizations, however, RDS can be an affordable alternative, especially since the number of users that can connect is limited only by the server's hardware.
With lower costs than VDI and higher performance than RDS, the DaaS model is a balanced approach to desktop virtualization. As a cloud service, it can also provide an added level of flexibility, such as the ability to scale up and down faster than locally managed platforms. And since virtualization is abstracted away to the provider, hiring a VM specialist isn't necessary.
How to Get Started
Desktop virtualization is a valuable technology stack for any business looking to minimize support and security concerns, centralize data and applications or even improve performance. To get the most out of going virtual, make sure you understand the implications for the end users.
More importantly, make sure you have the appropriate infrastructure in place before making the switch. If your teams still use traditional desktops, there's a considerable amount of data backup and transfer required during migration to virtualized desktops. While virtualization can simplify your operations, it's not a transition you want to approach haphazardly.