Symptom:
When VCHA is configured, the pre-upgrade check at Stage 2 of the vCenter Server upgrade fails with the following error:
The vCenter Servers managing the source and target appliances are not the same. Please specify the details of the same vCenter Server that manages both the source and target appliances and restart the upgrade.
vCenter Server
This occurs if you select "Install" in Stage 1.
Disable the VCHA configuration and perform the vCenter Server upgrade again.
During a vCenter Server upgrade, there are instances where the default storage size cannot be selected due to KB412941, which may prompt users to select "Install" in Stage 1. However, if you are operating in a VCHA configuration, you must first remove the VCHA configuration before selecting Install.