I've currently got a pair of vSphere5 standard servers (physical, not VAs) managing about a hundred ESX 4.1 and 5 hosts in two different physical and logical datacenters. With our last purchase, we bought another vSphere license for the new vS server. I unmanaged all the ESX servers in one datacenter and added them to new vSphere server.

Our previous single-vS-server layout used to be:

-vSphere1
--Datacenter1 (where the physical ESX host was located)
---Folder
----ESX server1
--Datacenter2
---Folder
----ESX server2

Now it looks like

-vSphere1
--Datacenter1
---Folder
----ESX server1
-vSphere2 (new vSphere server)
--Datacenter2
---Folder
----ESX server2

ESX server2 was removed from vSphere1's inventory and added to vSphere2's, so it is now managed by vSphere2.

This is nice and all, as no vSphere <--> ESX management traffic leaves the physical datacenter, except for one huge oversight: when I go to clone a VM, the opposite vSphere server (and thus other datacenter) does not show up in the list on the first page of the wizard.

Is this a bug, a license limitation, or is it just simply not possible to clone a VM from an ESX box managed by one vS server to another ESX box managed by a /different/ vS server?