With the release of Citrix XenDesktop 7 two provsioning methods are now available which fully support hosted shared (HDC) and hosted private (HDC). The first provisioning method is Citrix Provisioning Services (PVS) and the second is Machine Creation Services (MCS).
There are a couple of important differences between the two provisioning methods which you need to know before choosing the right method for your design. In one of my earlier articles I showed a decision tree which helps choosing between both methods. I would recommend to read this great article about storage resource usage, by Nick Rantalan, as well.
This article focusses on a very important difference between Citrix Provisioning Services and Machine Creation Services, Advanced Image Management.
Advanced Image Management
Advanced Image Management (AIM) is more than simply assigning an image to a specific machine or a group of machines. It’s about a proper way of upgrading and assigning images according to DTP principles in a simple and time efficient manner. Automation plays an important part of AIM as it saves time and more importantly leaves out the possibility of human errors. Andrew Morgan wrote an excellent article about why you want to prevent human errors by using automation.
PVS offers great image versioning functionality, automated DTP and even automated image updates with the integration of third party solutions like Microsoft System Center Configuration Manager. This Citrix article explains the functionality in fine detail.
MCS image management completely depends on the hypervisor snapshot functionality. We deploy a VM manually , customize it according to needs, manually or with third part tooling, manually create a snapshot, and update the machine catalog to work with that snapshot.
While working with MCS is very straightforward and easy, XenDesktop does not provide a way of doing any AIM for MCS. This might not sound like a big deal but think about daily updates of anti virus dat files or monthly (Windows) updates.
Each and every time we update an image for these repetitive tasks, it’s the same manual or scripted set of tasks. By automating, this would spare us a lot of time!
Advanced image management tasks
As said earlier, Citrix PVS offers very nice functionality to perform image management. Is this enough to call it advanced image management? In my opinion it does a great job but the feature set is not complete. There are still to many deployment tasks before we are able to create an image we can provision.
Is it fair to expect that Citrix would deliver the end to end solution for AIM? Not really! PVS and MCS are provisioning products which means they provide a machine with a pre created image. Citrix PVS and MCS are not deployment products like RES Automation Manager and Microsoft System Center Configuration Manager.
When thinking about advanced image management we need to start with defining the what and how of image management. As a starting point I’ll list the image management functionality that PVS currently offers.
- vDisk versioning
- Automated vDisk promotion from Development, Test or Production (DTP) targets
- Automated vDisk updates combined with for example SCCM or RES Automation Manager
While these are already great features I still expect more when we are speaking about “Advanced” image management.
In my opinion AIM consists of a fully automated process, without manual intervention, that starts from scratch and delivers a product.
My expectations of “AIM” are very high and may even seem a bit far fetched but bare with me.
Automated AIM should offer at least the following functionality without having to do a single manual task:
- Deploy a new MCS image and assign this to a Machine Catalog of test machines
- Create a new MCS image version and assign this to the “Test” Machine Catalog
- Assign properly tested MCS image versions to the “Production” Machine Catalog
As you can imagine these tasks require a solution to be able to perform:
- Hypervisor actions ; on Microsoft Hyper-V, Citrix XenServer and VMware vSphere ESX
- Deployment actions for Microsoft Windows
- Automation actions for Citrix XenDesktop
Of course there are all kind of products to manage the above mentioned actions but there is no end to end solution, right?
What if I told you that there is an end to end solution which makes this all possible? I’m kidding right? Or not? Keep on reading!
Let’s dig a whole lot deeper in what actions we need to take for each of the AIM functionality. Whenever I want to automate something I always start by doing the steps manually and create a Visio flowchart.
Here are the flowcharts for the AIM functionality described in this chapter.
Deploy a new MCS image and assign this to a Machine Catalog of test machines
Create new MCS image versions and assign this to the “Test” Machine Catalog
Assign properly tested MCS image versions to the “Production” Machine Catalog
As you can see this is a very detailed overview of all the steps involved in the process of AIM. Although it is nice to know which steps go into certain actions it would be a shame to not put it to proper use!
The Citrix XenDesktop 7 Advanced Image Management toolkit
Maintaining the Advanced Image Management toolkit proved to be a very high intensive project. Aside from that there simply weren’t enough actual users to justify putting in the amount of work it needed. I have stopped distributing and maintaining the toolkit but intentionally didn’t remove this article because I still believe in the need for Advanced Image Management. Hope you still find some guidelines in this article to help you on your journey.