Deploying Citrix XenApp
- Published: Tuesday, 21 October 2008
As already described in the often referred article Terminal Server Basic Concepts article arranging 100% identical servers is the main target of a Terminal Server administrator. At presentation and discussions about this goal I often got the question if this also counts to the installation of Citrix Presentation Server / XenApp. After the logically answer (Yes, of course) most times the question is fired how this should be done. In this article I will explain which methods are available to deploy Citrix Presentation Server / XenApp.
The first methodology is the traditional manual installation. With the manual installation you will run the installation from the CD, install the support software (like .Net Framework and the Java Runtime Environment) and start with the installation. During the installation you need to fill in several configuration settings like creating or joining the farm, selecting the correct database (and setting up a connection to the corresponding server), shadowing settings and so on. Although the installation of Citrix Presentation Server is not really difficult you need to have some knowledge about those settings and a small mistake can cause a re-installation. Logically this methodology is not suitable to gain the 100% identical servers goal, because with manual actions mistakes can be made (even when the installation is described step by step in a installation guide).
Another often used technique is cloning. With the cloning methodology you install one server completely including operating system, supporting software, Citrix XenApp and the client application which will be published. Cloning a server arranges 100% identical servers, because the machines imaged with the clone have exactly the same configuration. Unfortunate with cloning everything is exactly the same so you need to change some settings and components on the server where the clone is deployed. For Citrix XenApp this is not very difficult. There are just a few registry settings and the MF20.DNS which needs to be altered. So for installing Citrix XenApp cloning is not a bad option. But you will find out if the client applications did not register unique identification objects, computer name, GUIDs within the registry or configuration files, which can cause that the back-end server (communication) is not working as expected. When using cloning, use at least a product that automatically alters the Windows unique (computer name, SID) and automate changing the unique identifiers for Citrix Presentation Server and the installed applications.
Citrix has built-in the possibility to install the product unattended via the MSIXEXEC command and parameters. Using this method via the command line options of the MISEXEC command together with providing the Citrix settings (the same as in het manual installation) the product is installed without any manual intervention. I already described in the article series "How to Citrix Presentation Server Unattended" which parameters are available, how they can be used and how supporting components also can be installed unattended. This methodology is definitely usable to install your server in the same way. Just like all command line MSIEXEC installation you should find a way to guarantee that the installation script is carried out the right way. For example this can be arranged by creating a scripting structure/framework or embedding the command line in an Electronic Software Distribution System.
The unattended installation is a methodology I often use. But in scenarios the customer does not have a software distribution in place already, I advice to take a look at a system that fully support and understand the Terminal Server basic concepts. The big advantages of such product is that the configuration of the Citrix configuration is fully embedded within the product, so you can configure the Citrix configuration out of the graphical user interface of the product. Also most times such product fully supports the DTAP (Development Test Acceptation Product) principle with a few clicks instead of a difficult scripting when using the unattended installation. Probably you understand that this is the perfect solution for gaining the 100% identical rule. A very good example of such a product is visionapp Server Management Suite, which I have described in detail in this review.
In this article I described the possibilities to deploy Citrix Presentation Server / XenApp on your infrastructure. For every methodology I also mentioned the practicability of the methodology to apply to the main rule of the Terminal Server concept to keep all servers 100% identical. Out of the methodologies the unattended installation and the software product are the best option to use.