Virtual Desktop Infrastructure (VDI) is an alternative desktop virtualization method, one that utilizes a server to centralize management of client desktops. It enables central management and deployment of user desktops and yet provides each user the capability to customize a unique desktop with admin rights if necessary.

VDI is a comprehensive set of Microsoft and partner technology, enabling centralization of desktops, applications, and data. It provides Enterprise IT with integrated management of physical, virtual, and session-based desktops, centralization of user data, and improved application delivery. VDI is best suited for contract and offshore workers, users who need access to corporate desktops and applications, and users who occasionally work from home and whose primary desktop is covered by a corporate license.

VDI is one form of desktop virtualization strategy that can help organizations meet users’ needs for flexibility and mobility, while alleviating pressure on information technology (IT) departments regarding compliance, security, and managing costs. Desktop virtualization, while separating the elements of traditional desktop computing, can enable more dynamic centralized management. It is, quite simply, the act of separating one computing resource or layer and storing some or all of them in a data center. This leads to reduced dependency between layers, rather than locking the various layers together. User state virtualization isolates and centralizes user data and state; application virtualization isolates and centralizes applications management and deployment; and desktop virtualization isolates and centralizes operating system management and deployment.

In short, the key benefits of VDI are that it provides integrated management of virtual, physical, and session-based desktops, including non-Microsoft infrastructure; it facilitates improved business continuity through data centralization; and it offers improved flexibility and desktop location independence, enhancing work scenarios such as work from home and “hot-desking.”

Many desktop virtualization options and combinations are available, so the development of a desktop virtualization strategy requires three distinct steps:
1) mapping the available technologies;
2) defining user needs; and
3) matching technologies with user needs.

Desktop virtualization options are many, and the technologies are divided into essential and discretionary. Essential technologies are the first steps that need to be considered, due to the possibility of obtaining significant benefits in the short term with limited investments; and given their relatively easier deployment. They are user state virtualization, which separates the user data and settings from any PC and enables IT to store them centrally while also making them accessible on any PC; and application virtualization, which isolates applications from each other and solves compatibility issues by allowing applications to run together despite the fact that they may require the same resources from the operating system. Application virtualization enables IT to store the application centrally and stream it to a desktop based on user access. IT completely removes the applications from the desktop footprint.

Discretionary technologies allow for significant efficiency and flexibility, and require more sophisticated technical skills and a larger investment of IT resources. The two discretionary technologies are client-hosted and server-based. Client-hosted desktop virtualization is a type of machine virtualization technology that separates the operating system from the physical hardware and allows a single PC to run virtual machines side by side with the host OS. Server-based desktop virtualization solutions allow the execution of an environment at one place and presentation of that environment or user interface at a different location. They use remote desktop protocols (RDP) to decouple the user interface location from the execution environment location. Server-based desktop virtualization technologies include Microsoft Terminal Services Remote Desktops and VDI. Microsoft Terminal Services Remote Desktops means that remote desktops use session virtualization to partition a single OS into multiple user sessions in a cost-effective manner. With VDI, organizations can run multiple desktops, each in a virtual machine, on the same server in a datacenter and use remote desktop protocols to allow a user to access the desktop outside the data center.

Defining user needs is the second step in defining a desktop virtualization strategy. One must identify user needs and scenarios that could benefit from a particular virtualization technology. Microsoft has identified five Windows Optimized Desktop Scenarios to help simplify this process. Each usage scenario has unique IT and User requirements. The User Scenarios are identified as mobile workers; office knowledge workers; task workers; contractors and offshore workers; and “work from home” workers. The mobile workers scenario identifies the workers as sales professionals, consultants, and accounts, whose user requirements are listed as needing access to data and applications anywhere, anytime; having easy migration; and needing access to data and applications anywhere, anytime. For these workers, their IT requirements are identified as data protection and compliance; replaceable PC in case of a lost or stolen laptop; and needing a full, rich desktop environment.

The third desktop virtualization strategy step is matching technologies to user needs. For the mobile workers identified above, the optimized desktop scenario would be a replaceable PC, which provides flexibility of user settings, ease of user migration and a high level of local data protection. Key Microsoft technologies for this scenario are application virtualization, Microsoft Enterprise Desktop Virtualization (MEDV), folder redirection, client side caching, and roaming user profile. All these technologies will help these mobile workers get their jobs done. Encryption is also used to help maintain data protection in case the mobile workers’ laptop computer is lost or stolen.

MEDV enhances deployment and management of virtual machines (VMs), providing a seamless user experience independent of the local desktop configuration and operating system. MEDV helps mitigate compatibility issues between applications and operating systems by allowing organizations to run multiple operating systems on the desktop PC.

In desktop virtualization, the software instructions can be executed locally or centrally. In local execution, they are performed locally on the client device, such as Microsoft Office running on a traditional PC and storing documents locally on a PC hard drive. In central execution, the software instructions are performed remotely, as in a data center on a server; and also require network connectivity from the client device to the computing device in order for the user to provide input and receive output. Central execution can provide a higher level of security because the software is contained in the datacenter. Local execution provides richer user features and better performance on graphic and audio compute intensive software, according to “Desktop Virtualization Strategy,” Microsoft Corp.).

Desktop virtualization strategy can be implemented in any organization to meet current needs, but it is important to analyze user’s needs in order to execute proper solutions.