You can use the GUI installer to perform an interactive upgrade of a vCenter Server Appliance 5.5 or 6.0 that uses an external vCenter Single Sign-On or Platform Services Controller instance to vCenter Server Appliance 6.5 with an external Platform Services Controller. You must run the GUI upgrade from a Windows, Linux, or Mac machine that is in the same network as the appliance that you want to upgrade.

Figure 1. Upgrade Workflow of a vCenter Server Appliance with an External Platform Services Controller

Upgrade workflow that consists of two stages