String Theory

Date:

09/01/2010 (Wednesday)
Time: 11:00AM – 1:30PM EDT

Description:
The User Group
meetings provide members with an opportunity to share and learn about
common issues and utilization of Server Based Computing technology.
Additional segments include troubleshooting tips, best practices,
enterprise solutions, technology trends, vendor presentations and
upcoming activities of interest.

Agenda:
11:00am: Registration
11:15am: Opening Remarks and Organization News
11:30am: Citrix Announcements – Product Updates, Beta Announcements & Tech Releases
11:45am: Lunch
12:00pm: Citrix XenDesktop – Jonathan O’Brien, Citrix Systems
1:00pm: Open Discussion

Location:
Microsoft Southeast Regional Office – Alpharetta
1125 Sanctuary Pkwy., Suite 300
Alpharetta, GA 30009
Phone: (678) 629-5700

Registration: http://www.acug.org/index.php?view=details&id=2%3Aseptember-atlanta-citrix-user-group-meeting&option=com_eventlist&Itemid=53

If you are a XenApp administrator you have no doubt utilized "qfarm.exe /load" to display the load on your Citrix XenApp Servers. These load values can identify issues with your servers in addition to determining which server is the least/most loaded in your farm. The one key component missing in this display is determining the reason for the load evaluator value.

This is where Windows PowerShell comes into play. If you haven’t already, you need to download the Citrix XenApp Commands Technology Preview (v2). You must be running XenApp 5 on either W2k3 or W2k8.

Note: XenApp 6 comes with this PSSnapin preinstalled as part of the core software. However as you will soon see the features are not the same.

Once you have installed the Citrix PSSnapin, power up PowerShell and run the following commands:

Add-PSSnapin Citrix.XenApp.Commands
Get-XAZone | Get-XAServer -onlineonly | Get-XAServerLoad | format-table -auto

The first line imports the XenApp commands. “Get-XaZone | Get-XAServer –onlineonly” is included to only return servers that are currently online. If the Get-XAServerLoad cmdlet is run and encounters a server that is offline, it will error out and stop the whole process. (Not the way I would have it handled, but that is for another day. ). Once it is run you will get a display similar to below.

As you can see you not only got the Load value, but you also got the value for each component that made up the rule.  In the first example you can see that the memory is at 11% which is contributing to the load of 1100. This information has been invaluable in a couple of different instances; one where the box was responding, but the Load Throttling was keeping the server from taking connections, and another where I discovered that Page Swaps were hammering one of the servers.

DISCLAIMER: The Get-XAServerLoad that is included with the PSSnapin in XenApp 6 does NOT include the Rules property. I discovered this fact while working on this blog post. I have no clue why it was removed, but I will try and find out.

Today at work  it was brought to my attention that XenServer 5.6 dropped support for Windows XP 64 bit. I had only just recently started work with XenServer on a new project. This is a big deal for us because one of our VDI XenDesktop pilots is for a statistical application running on Windows XP 64 bit on XenServer 5.5.

Today at the end of the day the project manager was mentioning that that was a bad decision and even mentioned utilizing VMware as our backend for that environment.  So this evening I started doing some research and came to realize something interesting. XenServer 5.5 didn’t support 64 bit either.  So XenServer 5.6 doesn’t support 64 bit XP, but neither does 5.5.

Interestingly enough we have been having some problems with these images so now we have to wonder if it is because there is a reason Citrix doesn’t support it. If you are running Windows XP 64 bit images on your XenServers I would love to hear from you.