You create a vCloud Director server group by installing the vCloud Director software on one or more Linux servers, or by deploying one or more instances of the vCloud Director appliance. During the installation process, you perform the initial vCloud Director configuration, which includes establishing network and database connections.
The vCloud Director software for Linux requires an external database, whereas the vCloud Director appliance uses an embedded PostgreSQL database.
After you create the vCloud Director server group, you integrate the vCloud Director installation with your vSphere resources. For network resources, vCloud Director can use NSX Data Center for vSphere, NSX-T Data Center, or both.
When you upgrade an existing vCloud Director installation, you update the vCloud Director software and the database schema, leaving the existing relationships between servers, the database, and vSphere in place.
When you migrate an existing vCloud Director installation on Linux to the vCloud Director appliance, you update the vCloud Director software and migrate the database to the embedded database in the appliance.