Tech Kaizen: Virtual Desktop Infrastructure (VDI)

Desktop virtualization is the act of decoupling the different computing layers and storing some or all of them in a data center. Virtual desktop infrastructure (VDI) is the practice of hosting a desktop operating system within a virtual machine (VM) running on a centralized server. VDI is a variation on the client/server computing model, sometimes referred to as server-based computing (SBC).

Let’s look at VDI from a high level and compare it to more traditional server-based computing models.

The image on the right shows a traditional SBC model. The users all have access to a desktop GUI via an individual session on the terminal server. This server has a single OS installed; an instance of Terminal Services to provide the sessions and session management, and a set of applications that can be used by all the users on the server.

In the VDI model on the left, a single server is used again, but a hardware virtualization layer is added to this server in place of a more traditional OS like Windows Server. The Virtualization layer provides numerous Virtual Machines that are each supplied with an operating system, applications, and a unique GUI / desktop environment for each user.

As you can tell by the image, a VDI solution provides the same basic functionality of a traditional SBC solution. This functionality is (primarily) to provide a centralized desktop via a protocol like RDP or ICA. Besides the Virtualization layer and numerous OSes, the two solutions look almost identical. (The key word is ’almost’.)

With VDI you gain a couple of benefits that you cannot achieve in a SBC environment, including things like:

The ability to provide a unique environment for each and every user.
Each of these environments can be completely customized with different apps and settings without impacting other users.
Users can be granted more control of their own “virtual” desktop to allow them to install and modify applications if needed.
Applications that were not multi-user friendly (i.e. “we can’t get this to run on Citrix”) can be run in this environment since each instance is just like installing the app on a new desktop.

ref:

Virtualization Wiki - http://en.wikipedia.org/wiki/Virtualization

Introduction to Virtualization - http://www.kernelthread.com/publications/virtualization/

Virtualization Best Practises - http://support.ca.com/phpdocs/0/common/impcd/r11/virtualization/doc/virtualization_best_practices.pdf , http://support.ca.com/phpdocs/0/common/impcd/r11/virtualization/virt_main.htm

Virtualization: Fueling Green Data Centers - http://msdn.microsoft.com/en-us/library/dd347164.aspx

Microsoft Virtualization Portal - http://www.microsoft.com/virtualization/en/us/default.aspx

Virtualization White Papers - http://www.microsoft.com/virtualization/en/us/resources.aspx

Virtualization information on Microsoft Technet - http://technet.microsoft.com/en-us/virtualization/default.aspx

Virtualization Case Studies - http://www.microsoft.com/virtualization/en/us/case-studies-featured.aspx

Microsoft Virtualization learning portal - http://www.microsoft.com/learning/en/us/training/virtualization.aspx

Virtualization implementations and optimization guide - http://searchservervirtualization.techtarget.com/tutorial/Virtualization-implementations-and-optimization-guide

VMWorld 2010 Presentations - http://www.vmworld.com/community/conferences/2010/knowledge-experts