With an extensive history dating back to the 1960s, virtualization has evolved with the changing business and IT landscape and continues to be a relevant tool in helping companies align their business and IT objectives. After adopting and realizing the benefits of server virtualization, many companies are now looking toward the next logical step: desktop virtualization.

Desktop virtualization, or Virtual Desktop Infrastructure (VDI), decouples the desktop from the physical machine by hosting desktop operating systems, data and applications in "virtual desktops," which in turn are hosted on remote servers in a data center. These virtual desktops can be accessed through thin clients, as well as traditional desktop computers. By centralizing this software, Desktop virtualization offers users the full functionality of a conventional physical machine, without the hassle application updates or computer failures typically entail.

However, as organizations turn to desktop virtualization as a solution to their desktop infrastructure challenges, they face problems with high licensing costs, stiff hardware requirements and retraining user and technical communities. Here are the key roadblocks to successful VDI implementation:

Complex multi-tier architecture demands
Unlike the traditional desktop, which is simpler and less dependent on the enterprise architecture, desktop virtualization demands huge effort in terms of designing a scalable and secure infrastructure including the network, server architecture, storage architecture and security architecture.

Increased downtime
Traditional desktop virtualization implementation is network-dependant, as the desktops are hosted and accessed remotely. If steps are not taken to ensure adequate network bandwidth, this can result in increased downtime in the event of a network failure.

Creating the right user profile
Task-based workers who use fixed processes are ideal candidates for desktop virtualization; however, virtual desktops may not be suitable for knowledge workers and users who access rich applications frequently. Segmenting the user profiles thus proves essential when implementing VDI.

Ensuring the availability of drivers for printers and peripherals: Legacy printers, Scanners need additional devices and drivers to enable hardware redirection

Growing deployment base and resulting application performance and scalability issues:

• Additional investments in terms of server hardware, storage, network and software

To address and resolve these challenges, the implementation process is critical. Typical implementation should follow a structured framework involving the Plan, Design, Test, Pilot and Rollout phases.

Plan
Planning is vital for any implementation. Before designing VDI setup, determine the details of the existing infrastructure that will host the virtual desktops. Identify and segment users who can be migrated to the virtual desktop, and validate applications that need to be made available for the identified end users. Ascertaining hardware and software compatibility needs are essential for a successful VDI implementation.

Design
Design should take into consideration the security, scalability and availability of virtual infrastructure, as well as address the future roadmap of the organization to reduce complexities in the architecture and to support the growing user deployment base. For an additional level of security, two-factor authentication for external users is recommended.

The size of the virtual machines should also be taken into account: the smaller the virtual machine, the better the performance. Include WAN accelerators to provide sufficient bandwidth for external users. The virtual machines should only contain the operating system and application set, and data should be redirected to a centralized location.

Test
Create an isolated and secure environment where a prototype of the designed architecture can be implemented, analyzed, tested and manipulated. Performance measurement tools, such as perfmon and IO subsystem, that monitor the local server, remote client performance   and IO meter, can be leveraged to test the performance and draw attention to any necessary changes in the architecture.

Pilot
For the widest degree of end user success, the pilot population should reflect all aspects of diversity of the computing environment, including as many as possible end user device and software combinations, as well as a diverse set of user profiles. The pilot(s) should be conducted with an emphasis on real-world testing and with the goal of identifying, prioritizing, and fixing any bugs. This will help in ensuring all other hardware viz printers, scanners and other peripherals are available for all virtual desktop users.

Rollout
An important prerequisite before beginning VDI implementation is to establish a complete load balanced active directory infrastructure that accounts for all appropriate departments, user accounts, computer accounts, profiles, policies and folder redirection. When rolling out the VDI solution, migrate users in batches based on business function or department.

By adhering to the basics of these five phases, organizations can overcome the common setbacks of implementation and reap the full benefits of desktop virtualization.

Benefits of VDI
"Anywhere access" is one of the chief benefits of a virtual desktop solution. Virtual desktops provide mobility to employees and enable them to access their desktops from work, travel locations or at home using any device.

Organizations may be concerned that granting employees true anywhere access - from any device or location - may pose issues with security and compliance. Security or cross border regulations stipulate that certain workers, such as contractors, vendors or home users, should not access data on their local workstations. However, VDI technology stores data on a protected central server rather than on the local device, allowing employees to access this data without compromising its security.

VDI technology also maximizes time and resources for IT departments through centralized desktop management. While traditional desktops need to be individually powered on and connected to the LAN in order to conduct maintenance or set up a new device, desktop virtualization centralizes these desktop management and stay-healthy activities, such as patch management, asset management, and the provisioning of desktops, among others. Business continuity and disaster recovery plans can also leverage the virtual desktops, rather than individually provisioning, configuring, and distributing PCs.

Centralized setup and maintenance result in lower capital expenditures and operating expense costs than those of traditional desktops. Organizations can also seamlessly migrate to newer versions of operating systems without individually upgrading the physical machines by hosting the new desktops virtually in the data center. By minimizing the overheads in migration, as well as eliminating the need for touch services or Hard IMACs, virtual desktop infrastructure contributes to a significantly reduced TCO.

The Future of VDI
Traditionally, organizations adopted virtual desktops for workers when security and compliance permitted virtual access, limiting this technology to corporate-provisioned PCs. As organizations move towards a "Bring Your Own PC" model, virtual desktops provide a vehicle to extend virtual desktops to other segments of workers through personal computers and devices. IT departments are focusing their efforts on managing the centralized virtual infrastructure, leaving the management of the physical machine to the individual employee user.

"Anywhere access" will take on new meaning with the advent of the "PC on a Stick" model. Researchers are developing an encrypted USB stick that will enable users to access their virtual desktops from any capable device, including PCs, laptops, thin clients, or smart phones.  As an added security measure, organizations will be able to send a "kill" command to lost or stolen USB sticks. Alternatively, or in conjunction with this USB virtualization technology, a security on-demand option that allows users to download the corporate virtual environment from the Internet is also in development. This will provide more security and less cost to the businesses and more flexibility and mobility to end users.

As larger sections of the end user community transition to virtual desktops, the industry is focusing on developing technology to enable heavier applications such as flash or media files for end user devices. This will necessitate larger central compute capability, more convergent networks and lighter end user computing devices. With increased ease of use, capacity, flexibility and mobility to end users, we can expect adoption of VDI technology to grow in leaps and bounds.