The vCenter Extension vService is a standard vService that vSphere 5.0 provides. With the vCenter Extension vService you can register virtual machines as vCenter Server extensions with minimal user interaction.

Typically, you register an extension with vCenter Server by running an MSI installer or an installation script in which you enter the credentials of a vCenter Server administrator and the connection parameters of the vCenter Server system. You can avoid these manual steps by using the vCenter Extension vService to register extensions in vCenter Server. vCenter Extension vService performs the following functions.

Provides the virtual machine with the connection parameters and a login token of the vCenter Server system on which you install the extension.

Registers the vCenter extension certificate of the solution with vCenter Server.

To deploy an extension using the vCenter Extension vService, you must deliver the vCenter extension in a virtual appliance that you deploy using OVF.