If you are looking to upgrade a 2008R2 XenApp 6.5 server to XenApp\XenDesktop 7.x, you will more than likely be uninstalling the 6.5 bits prior to installing the 7.x VDA. Currently, project Serenity is still in beta and appears to migrate mostly datastore objects and settings – you still need to manually migrate the user servers.
Per this Citrix article (which is a bit outdated) the only noted procedure is to uninstall hotfixes first then the core XenApp installation.
I have heard of a few issues with getting all of the bits uninstalled prior to installing the new VDA, so the suggested uninstall order is as follows:
- Uninstall the Citrix HDX WMI Provider
- Uninstall all XenApp hotfixes and rollup packs
- Uninstall core XenApp software
The HDX WMI provider has been the problem and fails to uninstall. If this component is left behind, it may attempt an uninstall, then fail, rolling back with no error. A potential fix is to run an installation of the component on top of the existing install, then the uninstall will be successful – the original install is located on the XenApp 6.5 installation media as CitrixHDXWMIProvider-x64.msi or if you have version 2.0.1 installed, the install is available from CTX131221