Virtually Worlds Apart: Understanding the Differences Between Server and Desktop Virtualization

Server virtualization has made rapid inroads into a majority of enterprise data centers. Encouraged by the tangible operational improvements, management benefits, and cost savings of server virtualization, enterprise IT shops now hope to achieve similar benefits with hosted virtual desktops (HVDs). Many companies have tested hosted virtual desktops in trials and limited proofs-of-concept. Now, many are at the point of planning larger deployments that will serve thousands of users.

While enterprises have gained some confidence in their ability to scale HVDs, they still run the risk of starting out on the wrong foot. Many mistakenly assume that server and desktop virtualization involve a similar approach, when, in fact, these two disciplines are extremely different - virtually worlds apart.

The following are topics that IT decision-makers should consider as they move forward with plans to scale HVDs. Keeping these key distinctions in mind could make the difference between a successful hosted virtual desktop reality and a real nightmare.

The Move

A vital aspect of server virtualization is the ability to move running virtual machines (VMs) from one physical machine to another. Mission critical applications need to be continually available, otherwise, user-productivity suffers from a lack of functionality and key business transactions can be dropped. Products like VMware’s vMotion exist to ensure the demand for 24 x 7 availability is met. The requirements for desktop availability are different. Desktops are not active 24 x 7. Virtual desktops and applications can be moved when users are signed-off or their machines are idle. Planning these activities during such down-time is a smarter approach than investing in additional software that drives up costs and is, frankly, overkill.

Security That Makes Sense

In these early days of desktop virtualization security basic concepts, such as covering passwords before storing or transmitting them, haven't been completely thought through by the VDI experts. The server and storage folks aren’t accustomed to the kinds of security issues that those involved at the desktop level have been facing for a long, long time. Yet, it’s the server and storage staff involvement at the virtual desktop level which opens up new issues. Personnel versed in security at the desktop level should also be leveraged for effective security, as should vendors with substantial real-world VDI deployments under their belts.

Integrating Effectively

A hosted VDI must integrate seamlessly with an existing physical desktop infrastructure. In an organization of any size, security, networking and authentication for physical desktops will have been selected to meet budgetary, regulatory, and compliance requirements. An HVD deployment must work seamlessly with these existing systems. By contrast, server virtualization is a consolidation effort mainly confined to the data center. There’s little difference between the way physical servers and the new virtual servers are accessed.

A major benefit of HVDs is the ability to grant access from an array of different locations. With this flexibility comes additional complexity. Access “on campus” may require resources ranging from particular applications to an assortment of drivers to particular printers. In contrast, access from remote locations may require an entirely different set of resources. The hosted VDI requires sophisticated logic to determine which resources a user can access based on their needs and location.

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