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Citrix XenApp 6.5 was a popular release, but this version of the company's application virtualization product is aging, and IT shops must consider whether it's time to update to XenApp 7.8.
Citrix released XenApp 6.5 in 2011 and its end-of-maintenance date passed on Feb. 24, 2016. Many administrators using XenApp 6.5 won't have to worry yet though, because end of maintenance isn't until Dec. 31, 2017 for customers that remain current in the Software Maintenance or Subscription Advantage programs. The formal end-of-life date for version 6.5 is Aug. 24, 2016, but Software Maintenance or Subscription Advantage program customers have until June 30, 2018.
Citrix XenApp 6.5 customers have some time before the software reaches its end of life, but admins should begin planning their XenApp migration now. The end of life will not cause XenApp 6.5 to stop working, but it means that edition will quickly become outdated and may leave customers vulnerable to potential security issues.
Get on the FMA train
If that isn't enough of a reason to make the transition to the latest version, XenApp 7.8, Citrix stated that going forward it will base its products on its FlexCast Management Architecture (FMA), which replaced the older Independent Management Architecture (IMA) in XenApp 7. FMA offers distinct advantages over IMA, such as its integration with the XenDesktop platform. Migrating to XenApp 7 allows Citrix customers to begin standardizing on the FMA platform.
Citrix designed FMA as a unified architecture for both application and desktop virtualization. The architecture improves scalability, and expands management and monitoring capabilities. In addition, FMA decouples XenApp version upgrades from operating system (OS) upgrades.
Citrix dropped several features from XenApp when it switched from IMA to FMA, which caused some shops to stand pat with version 6.5. Citrix started to bridge that feature gap in XenApp 7.7 by bringing back the old MultiZone Management feature, which provides admins with central management of XenApp deployments across several locations.
XenApp 7 uses a different architecture than XenApp 6.5, so admins should spend a lot of time considering the best approach to the upgrade process. Citrix recommends enterprise customers perform a phased parallel upgrade from XenApp 6.5 to version 7.8. This type of XenApp migration usually consists of four phases, so if anything goes wrong it only affects a small number of users.
Phases of a XenApp migration
The first phase of a XenApp upgrade is planning and design. That process includes training the IT staff, verifying application compatibility, reviewing system requirements and choosing an OS. IT should establish a concrete plan for the upgrade process.
The second phase of the migration involves upgrading to the Citrix StoreFront enterprise application store, which provides users with central access to their corporate apps. Many XenApp 6.5 customers still use Web Interface -- the predecessor of StoreFront -- which allows users to access virtual desktops or apps through a Web browser, but the end-of-life date for Web Interface is the same as XenApp 6.5.
To allow for a seamless migration, admins can design and configure a StoreFront environment parallel to the Web Interface one. Don't get confused by a change in vernacular from IMA to FMA. Citrix now refers to the server farms that Web Interface and StoreFront access as "sites."
Admins introduce XenApp 7 to the existing environment during the Web Interface upgrade. Citrix recommends using the user roaming feature to enable Active Directory group membership, which admins can use to direct users to the old XenApp 6.5 environment as they work on the new one. Active Directory groups are helpful for creating a pilot deployment program of selected users, and also for controlling the user experience, because during any complications, admins can simply swap a group from the new XenApp deployment to the old one.
The third phase is the actual upgrade to XenApp 7.8, and it's relatively straightforward. Begin by upgrading the license server to the current version of XenApp. From there, move on to setting up the Delivery Controller feature so it parallels the existing controller infrastructure in XenApp 6.5. Citrix provides a tool called the XenApp In-Place Upgrade Utility that can upgrade existing workers to XenApp 7.8 or add new deployments. Next, the XenApp Upgrade Utility migrates settings and other items from XenApp 6.5 to version 7.8.
The final phase of the migration is to upgrade the Citrix Receiver client software. Most large organizations will likely opt to deploy the upgraded Receiver using an automated software deployment tool.
The upgrade from Citrix XenApp 6.5 to XenApp 7.8 is not overly difficult, but it requires extensive planning due to the switch to FMA. During the migration process, it is extremely important to perform comprehensive testing after each phase before continuing on with the next one, to detect and resolve any issues before they affect the production environment.
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