Shannon Ma Virtualized

In the last part of Choosing an Automated Deployment Strategy for XenApp I will discuss installing XenApp via images.

Image-based Deployments

I haven’t really been a follower of image-based deployments in the past. It’s just too cumbersome to maintain separate images for all of the different types of hardware most companies have.

My view on this all changed once virtual machines started to crop up in the data center and this is the topic I’ll be covering here.  Virtual machines abstract the physical hardware away from the OS, so if all of your servers are virtualized then they’re all running the same hardware.  In this case, you just need one master image.

Image-based deployments with virtual machines require a few tools:

• Virtual machine software (XenServer, Hyper-V, …)
• A way to generalize XenApp on the master image (XenAppPrep)
• A tool that can deploy the virtual machine images (Provisioning Server, Altiris, …)

In one of my previous posts, I talked about a tool (XenAppPrep) I developed that automatically prepares a XenApp installation to be cloned, so I won’t cover that here. However, it should be noted that this process is important for all image-based deployment technologies, whether they’re for physical or virtual machines.

In order to have a complete automated strategy, we still need a tool that will allow us to deploy our virtual machine images. You can use conventional imaging tools like Altiris or have the ability to stream your images on-demand with Provisioning Server (PVS). I personally think Provisioning Server is probably one of the few technologies that will change the way data centers are run, but that’s another post all together.

Machines using the current version of PVS (4.5) do not save their state in standard image mode. For example, let’s say you’re streaming one master image (or workload as PVS refers to it) to a handful of your machines and save a text file to your C: drive. The next time you reboot this machine, the file will no longer be there. Depending on your XenApp implementation, this could be advantageous or not. Most XenApp settings are stored in the central IMA database and any user-specific changes can be captured by roaming profiles, so in many cases this may not be an issue.

Well, that wraps up my overview of the various ways you can deploy XenApp automatically. I hope this was helpful and if you have any questions or feedback don’t hesitate to drop me a comment.