Live migration overview

Live migration is the process of moving a virtual server from one host hypervisor to another by using virtual memory streaming. A duplicate of the original virtual server is created on another host, in real-time, from the disk contents, right down to the last byte of RAM in use. When the process is ready, the original virtual server is switched to the new one.

Using live migration means that, where possible, customer workloads can be moved off of a host that needs to be patched and rebooted to a host that is already updated. During live migration, most customers experience no downtime; a small percentage may notice a brief pause in their workloads, but the result is generally of low impact compared to a full reboot of a host and virtual server.