Thanks Andre.

Native iSCSI would be through a second system acting as a file server, correct? We would like to stay away from that...

A guest extend is basically using a dynamic disk on windows, right?

I guess the underlying question is: Can I use the lost disk space by using an extent?

I mean right now I still haven't found a solution to even create two VMFS3 storages. Basically, ESXi only allows me to create one VMFS3 storage per physical array from what I can see so far.