A new feature called vCenter Linked Mode has been introduced in vSphere 4. It allows several vCenter servers to form a linked mode group. When you connect to any of the vCenter server via vSphere Client, you see all of them behind a single pane of glass.
I got questions from time to time, “what does it mean for vSphere API?” More specifically, if you connect to one vCenter in a linked mode group, will you “see” all of them? If not, how can vSphere Client achieve that?