Virtual Desktop Infrastructure

Even though Windows XP has been a rock solid operating system-and runs very well on older hardware-some companies are dreading the idea of having to refresh their desktop fleet. It’s complicated and resource intensive, which means it’s an expensive proposition. So in many ways, it makes sense to consider an implementation of virtual desktop infrastructure where the processing happens on a server versus the desktop. We’ve all heard this before-with Terminal Services and Citrix you could run a desktop someplace else and reuse your hardware, but the configuration and management are just too much. This time around things have changed.

It’s actually pretty tough to define what a virtual desktop infrastructure, or VDI, is these days. But if you look at it in the simplest form, it is using virtualization to provide your end users with desktops. Many of you reading this book have already installed a guest partition with Windows Vista for testing, or are running Virtual PC and have a desktop operating system running in a virtual machine, so the concept is not completely new. But the VDI that we’re talking about is a little bit more complex than just running VPC, VMware workstation, ACE, or MED-V. We’re talking more about hosting desktop operating systems on your Hyper-V host. VDI is still very similar to Citrix or Terminal Services in that you are performing the processing in the datacenter, versus on a desktop system. The main difference between VDI and Citrix or Terminal Services is that with VDI you are creating a dedicated virtual machine for the end user to work in, versus having a shared environment.

Once you’ve created the virtual desktop, you can connect to it using some form of remote control software, like Remote Desktop Protocol (RDP), which is built into Windows VPS, VNC, or really any remote control software. This works okay for a couple of virtual desktops, but when you start getting a large number of virtual desktops, you may want to consider adding a connection broker in front of your virtual desktops. Originally, the connection broker was basically used to help determine which virtual desktop an end user should be connecting to or is assigned to. Today you can consider it to be much more than that. You can really consider the connection broker as almost an infrastructure access gateway for an end user. You can leverage that connection broker to give access to your virtual desktops, and also to your blade PC, servers, and even applications.

Just a few years ago there weren’t all that many connection brokers on the market. Primarily we used a Citrix presentation server as front-end RDP sessions to the virtual desktops. Today the connection brokers are much more sophisticated, with features like temporary and permanent assignments, virtual machine power management, graphics acceleration, and multimonitors. This allows your virtual desktop users to use mediarich applications, and many others.