Query on upgrading the OS Citrix servers (Storefront, DDC and License server)

Instructions

Storefront - Even as in transition stage while the Upgrade, mixed version of OS in server group is not supported.
Hence, new Storefront servers have to be built with the new OS to which the customer needs to upgrade to and create a new storefront server group. Once done, export and import the storefront configuration.

Storefront config export and import: https://docs.citrix.com/en-us/storefront/1912-ltsr/export-import-storefront-config.html

Note: Check the system requirements in the docs.citrix.com for the version of Citrix Virtual apps and Desktops to determine if the New OS is supported for the corresponding component.

DDC - Create a new Vm with new OS 

• Install the existing version of DDC component software on new server
• Join the server to existing site 
• Shut down other controllers and test if everything works as expected from newly joined controller 
• Remove other controllers from site 
• Add new VM  to the site 
• Upgrade the DDC component software to 1912 /2203

VDA - For VDAs, starting with version 2203, in-place upgrade of OS is supported in some scenarios as long as the version installed is currently supported . Refer to the product documentation for details. If your environment does not meet the criteria for a supported in-place OS upgrade, you must do the following:

• On master image, uninstall the VDA agent.
• Perform the OS upgrade and ensure the upgraded image is fine from OS perspective.
• Install the VDA agent post checking the system requirements to ensure that the upgraded OS is supported and tested with the VDA agent version, which needs to be installed.

PVS - In-place upgrade of the OS possibly will break the PVS servers. Hence, the below can only be done:

• Build a new server with upgraded OS.
• Install the PVS server component.
• Add the new PVS server to the farm.
• Follow the above steps for the number of servers to be added.
• Once done with the new servers addition to farm, remove the old servers from farm.

Citrix License server - It is not recommended to do in place upgrade of the OS on Citrix Licensing server. Hence you can follow the below:
 

• Ensure the snapshot of the Licensing server is taken.
• Take a backup of "MyFiles" folder in C:\Program Files (x86)\Citrix\Licensing.
• Uninstall the Licensing server.
• Perform upgrade of OS
• Install Licensing server and import the license files from back up of MyFiles folder.

NOTE:  The article is also valid for newer CVAD and PVS versions like 2402