Today was announced that long distance vmotion is now officially supported by VMware up to a distance of 200 kilometers. A team-up from Cisco, VMware and EMC did some tests, proving the posiblities. Long distance vmotion is basically the vmotioning between two remote datacenters, enabling follow the sun, follow the moon, or evacuating a datacenter anticipating on a soon-to-be-disaster (“the tornado is coming”).
Of course some limitations apply. Things like maximum latency of 5ms round trip and minimum bandwidth of 622 Mbits/sec apply, but still! Long distance vmotion is a fact, and I guess will soon be accepted as an enterprise solution just like normal vmotion has.