Part 2: XenDesktop
As stated in Part 1; a few of my clients have been wondering whether they should upgrade XenApp and XenDesktop. Every environment is different; therefore there is no one-size-fits-all answer. What works for one client does not always work for another. We need to look at some of the factors that go into this decision. Since both products have different purposes, I am going to discuss each product separately. You are not required to upgrade both your XenApp environment and your XenDesktop environment at the same time. We are going to focus on XenDesktop for this article (See my previous blog for XenApp). With so much to cover, I’ll cover some of the major issues I’ve dealt with. Please feel free to post questions below, for issues I may not have time to mention.
At the time of this article, XenDesktop 7.5 is the latest version. When you purchase XenDesktop licenses, XenApp utilization is included as part of the XenDesktop license. In part 1, I was hesitant about upgrading to XenApp 7.5. That is not the case for XenDesktop 7.5. To upgrade to XenApp most likely required a change in architecture (from IMA to FMA). For XenDesktop, the FMA architecture has been utilized for a while. So, unless you are upgrading from a really old version, you will stay within the same architecture. If you are on a really old version of XenDesktop, time to perform a migration.
Deciding factors for XenDesktop:
- Upgrade or Migration: Can you do an in-place upgrade or do you have to build a new farm and migrate to it? If you have a version of XenDesktop lower than 5.x or you are on Express edition, then you will need to perform a migration. There are migration tools for XenDesktop 4, but anything lower and you are in essence building a new implementation. If you are on version 5.x or higher, then Citrix eDocs tells you to do an in-place upgrade if you want to keep your original farm configuration. You can have an older XenDesktop and a XenDesktop 7.5 farm in operation at the same time, but they are separate. Components of versions below 7.0 will not recognize the 7.x components. And XenDesktop 5.x settings cannot be imported into XenDesktop 7.5. They must be brought in by upgrading the delivery controller and VDAs.
- Architecture: As mentioned previously, there is no drastic change in architecture unless you are on a version of XenDesktop prior to version 5.
- Complexity: Complexity has been decreased in many features. In the past, larger XenDesktop farms required Provisioning Services (PVS) for a number of reasons. PVS is can be complex to implement and administer. In XenDesktop 7.5 Machine Creation Services (MCS) has been improved to the point that the gap in performance between PVS and MCS is not significant. PVS may now only be needed for large enterprise farms. The significances of this are that without PVS, we remove a demanding architectural piece, MCS is easier to administer than PVS, and we conserve server resources.
o As stated in Part 1, do you have the technical knowledge on the latest version of XenDesktop or will you need help? The difference in XenDesktop 7.5 to older versions depends on how old your previous version is. The older your previous version, the greater the difference in the latest version. If you are going from 7.0 or 7.1, then the differences are mostly in feature set. Anything older and significant differences are involved.
o Features: The HDX feature set in XenDesktop 7.5 has been improved. For example, greater client resource and peripheral utilization. Better storage resource usage and storage support. Platinum licensing includes AppDNA and XenMobile utilization. Web Interface support has been reintroduced for XenDesktop 7.5, so that can still be utilized if StoreFront is not an option. This is significant for many reasons. One important reason is that StoreFront requires a NetScaler for secure external connections. If you do not have a NetScaler configuration in your environment, you will need another solution for external access besides StoreFront.
I could go on with more detail, but it all comes back to the basic question: Should you upgrade your XenDesktop environment to XenDesktop 7.5? The answer actually depends on your environment, corporate policy, and resource availability. If the needs and abilities are there, then go right ahead. XenDesktop 7.5 is an improvement over previous versions.
What have you decided – is it time to upgrade?

Craig R. Kalty (CCIA, CCEE, CCA, MCITP:EA, MCITP:SA, VCP)
Sr. Network Consultant
[email protected]
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