Nir, thank you for your help and practical examples. I'll try to simulate.
In fact, most companies that actually have different offices do not share the same
SAN/Storage structure , there are physical limitations and network details and time that
make procedures impossible - As I said, storages that work differently, are also a
limiting factor.
Export Domain, we can count today, but in six months, we don't know if it'll still
be there.
Most hypervisors support Live Migrate/Off line migrate between "data centers".
It would be great to have this feature up to oVirt 4.5.x