Creating Desktop Images Specifically for VDI

By Hank Smith
Posted in Virtualization
On February 06, 2012

As many more companies start to adopt Virtual Desktop Infrastructure (VDI) as a solution for various user classifications, the question that typically comes up is “Should we use our existing physical workstation image?" In many cases this isn’t even a question; the customer assumes that the physical image will be used in their VDI environment. This article reviews reasons why it is common to utilize an existing image along with the reasons why not to use a physical image.

Why use an existing physical workstation image?

Companies will utilize an existing physical workstation image by P2V’ing (physical to virtual) the physical workstation. This is an easy way to have the corporate image become part of the virtual desktop environment. Typically the image has already been certified by the desktop team, making the validation easier. Core applications and lockdown have also been applied to the image.

Why use a clean image for a VDI environment?

In many cases, if a physical workstation image is migrated to the VDI environment, issues will occur. Typically this is due to hardware drivers, lockdown policies, etc. that lead to degraded performance and/or troubleshooting connectivity issues between the virtual desktop and connection broker. Plain and simple, the physical image was not developed with the intention of being virtualized. For example, during a recent proof of concept (POC), the customer insisted on migrating the physical workstation image to the VDI environment. This wasn’t a viable option, as the image utilized McAfee services extensively, preventing the installation of Citrix agents to the desktop. The same image was also being pushed application updates, which is not recommend in a thin provisioned VDI environment.

Gotham’s recommendation

Although migrating a physical workstation image is easy and straightforward, Gotham recommends building a clean image. The image would be intended for VDI environment utilizing virtualization tools (VMware VMTools or Citrix XenTools). Gotham also recommends keeping the image as clean as possible, decoupling the applications. Utilizing application virtualization (VMware ThinApp, Citrix Streaming, and Microsoft App-V) will greatly assist in keeping the image clean. When locking down the virtual desktops, utilize Windows Group Policy as opposed to local policy.

While importing an existing image is easier, it is by no means the best route to go. Building an image from scratch specifically for the VDI environment is the best choice. Utilizing application virtualization and/or published applications made available from an existing XenApp environment will lead to better performance and stability of the VDI environment. With the use of profile management software (AppSense, TriCerat, Liquidware Labs), the migration between physical and virtual desktops is much more streamlined.

Hank Smith

Hank Smith

Hank is an expert in the design, development, and delivery of cost-effective, high-performance technology solutions. As manager of Gotham’s Virtualization practice, Hank builds motivated, productive teams for Gotham’s large-scale networking and infrastructure engagements, develops implementation standards and methodologies around virtualization technologies, and manages overall design and implementation of multiple infrastructure projects.