Tag Archives: XenDesktop

CentOS 7 and Citrix – ctxvda status error

Over the course of the last few weeks, I’ve gotten an opportunity to explore building and publishing Linux virtual desktops using Citrix XenDesktop 7.11.  Now, I’m no Linux admin/expert which means configuring all this has been challenging at times even with the resources available on the web. Though the Linux VDA will support Red Hat, SUSE, and CentOS, I chose CentOS as my starting point because it’s free in that it does not require additional licensing to use beyond a 60-day demo period.

With that, my starting point for configuring CentOS 7 with XenDesktop 7.11 was the Citrix blog Installing the Linux VDA on Red Hat or CentOS 6.  I highly recommend this blog if you are new to Linux and need a launching pad from which to start your own feasibility testing for publishing Linux via Citrix.

Upon completing the installation of the Citrix VDA and executing ctxsetup to customize the VDA, I waited patiently (2 minute of hitting refresh) for the machine to register with the delivery controller but it never did and so commenced my Linux troubleshooting career.

1. On my Linux workstation, I started a terminal session and ran the command service ctxvda status to see if the VDA service was running:

1_ctxvda-failed

2. So the VDA service failed to start….but why?  Next I reviewed the VDA log file to see a reference to Citrix KB article CTX119736:

2_vda-log_error-message

Sweet!!!!  My solution is waiting for me….all I have to do is find the article and my issue will be resolved very shortly and I’ll be accessing my virtual desktop in no time.  BUT, if you try and find CTX119736, you’ll likely encounter the following:

2a_ctx119736-does-not-exist

3. Though I couldn’t find CTX119736, the more time I spent looking for it, the basic troubleshooting starting points became somewhat clear and really they are not that much different for Windows hosts….check the time, check the network, check name resolution, etc.  What I found going through those steps is that the time, the network and name resolution worked from the Linux workstation side, but the delivery controller could not ping the Linux workstation by name.  Looking at DNS on the server side revealed that though the workstation retrieved a DHCP address, a host (A) record was not created for it in DNS, thus the delivery controller could not communicate by name.  The DHCP scope options were set to dynamically update DNS records for clients that do not request updates.

3-dhcp-dns-dynamicupdate

4. I rebooted the Linux workstation and after doing so, the Citrix VDA service started and it successfully registered with the delivery controller.

4-ctxvda-service-running5_registration-successful

I was surprised that a name resolution issue kept the ctxvda service from starting altogether and it was one of the last basic options I checked.  I figured that if DNS/name resolution was the issue that the ctxvda service on the Linux workstation would start, but that registration would fail.  However, when troubleshooting ctxvda service errors from this point forward, name resolution will be my first test.

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XenApp 7.x Server Repeatedly Unregisters

Recently, a customer was experiencing a XenApp 7.x server that frequently “unregistered” with the XenDesktop 7 DDCs.  The problem was resolved by resetting the performance monitoring counters with the command lodctr -r.

lodctr

I’ve seen this type of thing happening on Citrix servers for years, but basically when an incoming ICA connection is made, Citrix will determine where to place the user based on a “load” value between 0-10,000.  A load of 10,000 means the server if full and it will not accept additional ICA connections.  However, in my experience, 10,000 has been an erroneous load value the majority of the time.

To determine the load of the server, Citrix uses Windows performance counters.  I found the following on the Citrix support site:

The load balance concept of XenApp depends on the use of Windows Performance Monitor counters to run the test and receive the correct statistics. If this is damaged or not installed correctly, XenApp will not be able to get a correct read, thus forcing a load of 10000 because the tests are failing.

Based on what I have seen this week, it looks like this problem can occur on servers running the XenDesktop 7.x VDA.

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Disable Citrix PN Agent FTAs in XenDesktop 7.x

If you are deploying XenDesktop 7.x and publishing both Windows 7 VMs and applications from a “XenApp” server, the Citrix Receiver installed on the Windows 7 VM will overwrite FTAs (File Type Associations) with those FTAs from published applications.  Normally this is not an issue, but it could be if you install say, Office on your Windows 7 VM and also publish Office for other users.  Receiver on the Windows 7 VM will launch the published applications rather than launching the locally installed instance of the Office suite.

To disable FTAs when using Citrix StoreFront, follow the steps below which can also be found here:

By default, file type association is enabled in stores so that content is seamlessly redirected to users’ subscribed applications when they open local files of the appropriate types. To disable file type association, you edit the store configuration file.

Important: In multiple server deployments, use only one server at a time to make changes to the configuration of the server group. Ensure that the Citrix StoreFront management console is not running on any of the other servers in the deployment. Once complete, propagate your configuration changes to the server group so that the other servers in the deployment are updated.

  1. Use a text editor to open the web.config file for the store, which is typically located in the C:\inetpub\wwwroot\Citrix\storename\ directory, wherestorename is the name specified for the store when it was created.
  2. Locate the following element in the file.

<farmset … enableFileTypeAssociation=”on” … >

  1. Change the value of the enableFileTypeAssociation attribute to off to disable file type association for the store.

 

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