Citrix Virtual Apps and Desktops

Upgrade considerations and limitations

Before you begin an upgrade, review these limitations and related considerations. They affect which components you can upgrade and which operating systems are supported.

The following limitations apply to upgrades:

  • Selective component install: If you install or upgrade any components to the new version but choose not to upgrade other components (on different machines) that require upgrade, Studio reminds you. For example, let’s say an upgrade includes new versions of the Controller and Studio. You upgrade the Controller but you do not run the installer on the machine where Studio is installed. Studio will not let you continue to manage the site until you upgrade Studio.

    You do not have to upgrade VDAs, but Citrix recommends upgrading all VDAs to enable you to use all available features.

  • Early Release or Technology Preview versions: You cannot upgrade from an Early Release, Technology Preview, or preview version.
  • Components on earlier operating systems: You cannot install current VDAs on operating systems that are no longer supported by Microsoft or Citrix. For more information, see Earlier operating systems.

  • Mixed environments/sites: If you must continue to run earlier version sites and current version sites, see Mixed environment considerations.

  • Product selection: When you upgrade from an earlier version, you do not choose or specify the product (Citrix Virtual Apps or Citrix Virtual Apps and Desktops) that was set during the installation.

Earlier operating systems

Let’s say you installed an earlier version of a component on a machine that was running a supported operating system (OS) version. Now, you want to use a newer component version, but that OS is no longer supported for the current version of the component.

For example, assume that you installed a server VDA on a Windows Server 2016 machine. Now you want to upgrade that VDA to the current release, but Windows Server 2016 is not supported in the current release you’re upgrading to.

If you try to install or upgrade a component on an operating system that is no longer allowed, an error message displays, such as “Cannot be installed on this operating system”.

These considerations apply to upgrading Current Release and Long Term Service Release versions. (The considerations do not affect applying CUs to an LTSR version.)

Follow the links to learn which OSs are supported:

Invalid operating systems

The following table lists the earlier operating systems that are not valid for installing/upgrading components in the current release. It indicates the latest valid component version supported for each listed OS, and the component version when installation and upgrade became invalid.

The operating systems in the table include service packs and updates.

Operating system Component/feature Latest valid version Install/upgrade not possible as of version
Windows 7 and Windows 8 VDA 7.15 LTSR 7.16
Windows 7 and Windows 8 Other installer components 7.17 7.18
Windows 10 versions earlier than 1607 VDA 7.15 LTSR 7.16
Windows 10 x86 version VDA 1906.2.0 1909
Windows Server 2008 R2 VDA 7.15 LTSR 7.16
Windows Server 2008 R2 Other installer components 7.17 7.18
Windows Server 2012 VDA 7.15 LTSR 7.16
Windows Server 2012 Other installer components 7.17 7.18
Windows Server 2012 R2 Other installer components * 1912 LTSR 2003
Windows Server 2012 R2 Server VDI 7.15 LTSR 7.16
Windows Server 2016 Server VDI 7.15 LTSR 7.16

Windows XP and Windows Vista are not valid for any 7.x components or technologies.

* Applies to Delivery Controller, Studio, Director, and VDAs.

What you can do

You have choices. You can:

Continue with the current OS

These methods are feasible for VDAs. If you want to continue using machines with the earlier OS, you can choose one of the following:

  • Continue using the installed component version.
  • Download the latest valid component version and then upgrade the component to that version. (This option assumes that the latest valid component version isn’t already installed.)

For example, you have a 7.14 VDA on a Windows 7 SP1 machine. The latest valid VDA version on Windows 7 OS machines is XenApp and XenDesktop 7.15 LTSR. You can either continue using 7.14, or download a 7.15 LTSR VDA and then upgrade your VDA to that version. Those earlier VDA versions work in deployments containing Delivery Controllers with newer versions. For example, a 7.15 LTSR VDA can connect to a Citrix Virtual Apps and Desktops 7 1808 Controller.

Reimage or upgrade the machine

These methods are feasible for VDAs and other machines that do not have core components (such as Delivery Controllers) installed. Choose one of the following:

  • After taking the machine out of service (turning on maintenance mode and allowing all sessions to close), you can reimage it to a supported Windows OS version, and then install the latest version of the component.
  • To upgrade the OS in a VDA machine without reimaging, you must first install the VDA version that is supported on the OS that you are upgrading to or upgrade the VDA after upgrading the OS. Otherwise, the Citrix software will be unsupported. You can upgrade to the following minimum OS versions when performing an in-place upgrade without uninstalling the VDA:
  • If the Windows version you plan to upgrade to does not align with the aforementioned guideline, you must uninstall the VDA before upgrading the OS, and then install a supported VDA version after the OS upgrade is complete.

Add new machines and then remove old machines

This method is feasible if you must upgrade the OS on machines containing a Delivery Controller™ or other core component.

Citrix recommends that all Controllers in a site have the same OS. The following upgrade sequence minimizes the interval when different Controllers have different OSs.

  1. Take a snapshot of all Delivery Controllers in the site and then back up the site database.
  2. Install new Delivery Controllers on clean servers with supported operating systems.
  3. Add the new Controllers to the site.
  4. Remove the Controllers that are running on operating systems that are not valid for the current release. Follow the recommendations for removing Controllers in Delivery Controllers.

Mixed environment considerations

When you upgrade, Citrix recommends that you upgrade all components and VDAs so that you can access all the new and enhanced features in your edition and version.

For example, although you can use current VDAs in deployments containing earlier Controller versions, new features in the current release might not be available. VDA registration issues can also occur when using non-current versions.

In some environments, you might not be able to upgrade all VDAs to the most current version. In that case, when you create a machine catalog, you can specify the VDA version installed on the machines. (This setting is called the functional level.) By default, this setting specifies the minimum recommended VDA version. The default value is sufficient for most deployments. Consider changing the setting to an earlier version only if the catalog contains VDAs earlier than the default. Mixing VDA versions in a machine catalog is not recommended.

If a catalog is created with the default minimum VDA version setting, and one or more machines has a VDA earlier than the default version, those machines cannot register with the Controller, and will not work.

For more information, see VDA versions and functional levels.

Multiple sites with different versions

When your environment contains sites with different product versions (for example, a XenDesktop 7.18 site and a Citrix Virtual Apps and Desktops 1909 site), Citrix recommends using StoreFront to aggregate applications and desktops from different product versions. For details, see the StoreFront documentation.

In a mixed environment, continue using the Studio and Director versions for each release, but ensure that different versions are installed on separate machines.

Upgrade considerations and limitations