How does migrating a running Virtual-Machine from one Hypervisor to another in a cloud environment actually work?
I know that it is possible and that this feature exists. But what does actually happen when a running Virtual-Machine is being migrated from one Hypervisor to another? I have a hard time imagining that this is possible without the slightest interruption?
While I may imagine that it might be somehow achieved if the bare metal is physically very close I struggle with the scenario to migrate a running virtual machine from an US data center to an EU data center for example.
Can anyone explain what is actually happening and how it is being achieved that there is no perceivable down time but remaining consistency?