XenApp Components part 2

In the previous post I covered the basics of Citrix Licensing. In this post I will go over the different versions of XenApp.

There are three levels of XenApp

  • Advanced Edition
  • Enterprise Edition
  • Platinum Edition

Here is table showing the difference in the three editions.


XenApp Components

This is the first of several posts detailing the different components of a XenApp (previously called Presentation Server) farm. I am going to make these short so that it is easy to read and remember.

Citrix Licensing Server

  • FLEXLM licensing service that runs a Windows 2003 server with IIS installed. Same licensing service that VMware uses.
  • Recommended that it is not on the XenApp server except for testing environments.
  • License file model with files with .lic extensions.
  • Administered from a web browser, a shortcut is placed off the Program, Citrix menu.
  • The user that installed the service is the only user that can administer the licenses. Once logged into the management page additional users can be added.
  • License files are tied to the hostname of the server and are generated/downloaded from mycitrix.com
  • License files can be rehosted to a new hostname if you need to move it to a new server.
  • If the license server is down the XenApp servers will function for 14 days without a connection to the license server. After that the servers will stop accepting connections.
  • There is not a way to have more the one license server.

Link to Citrix support site on licensing server.

Hello Virtual World

Hello, this is my first blog post.

My name is Jeremy Waldrop, I am a Systems Engineer for Varrow. Varrow is an IT Consulting company focusing on virtualization and storage. I am focused on server virtualization from VMware and application virtualization from Citrix.

I have 10 years experience in IT and have worked for a consulting company for all 10. I have done everything from NT4 to Active Directory migration, Exchange migrations, Novell migration to Citrix WinFrame, MetaFrame, Presentation Servers and Cisco routing/switching.

This blog will be focused on virtualization, storage and DR.

VMware DRS Stars

I get this question a lot from clients “In VMware DRS what is a star? what percentage of CPU/memory equals a star?” I also have wonder what makes a star and how is a star calculated.

My usual response is that a star is calculated by some DRS algorithm and that there is no exact answer to what a star is. I have never really found anything that explains how starts are calculated. The closest thing I have found is in the VMware DRS white paper http://download3.vmware.com/vmworld/2006/mdc9694.pdf

• Level 1 – Apply only five-star recommendations. Includes recommendations that must be
followed to satisfy cluster constraints, such as affinity rules and host maintenance. This level
indicates a mandatory move, required to satisfy an affinity rule or evacuate a host that is
entering maintenance mode.

• Level 2 – Apply recommendations with four or more stars. Includes Level 1 plus
recommendations that promise a significant improvement in the cluster’s load balance.

• Level 3 – Apply recommendations with three or more stars. Includes Level 1 and 2 plus
recommendations that promise a good improvement in the cluster’s load balance.

• Level 4 – Apply recommendations with two or more stars. Includes Level 1-3 plus
recommendations that promise a moderate improvement in the cluster’s load balance.

• Level 5 – Apply all recommendations. Includes Level 1-4 plus recommendations that
promise a slight improvement in the cluster’s load balance.

If anyone out there has some more detailed information on how a start is calculated in DRS I would love to see it.