Post-Copy Live Migration of Virtual Machines

This paper presents the design, implementation, and evaluation of post-copy based live migration for Virtual Machines (VMs) across a Gigabit LAN. Post-copy migration defers the transfer of a VM's memory contents until after its processor state has been sent to the target host. This deferral is in contrast to the traditional pre-copy approach, which first copies the memory state over multiple iterations followed by a final transfer of the processor state. The post-copy strategy can provide a "Win-win" by reducing total migration time while maintaining the liveness of the VM during migration.