Service level management for iterative pre-copy live migration

The ability to live migrate virtual machines (VMs) between physical servers without any perceivable service interruption is pivotal for building more energy efficient Cloud Computing infrastructures in the future. Nevertheless, energy efficiency is not worth the effort if quality metrics (e.g., QoS, QoE) are severely decreased by, e.g., dynamic consolidation using live migration. In this work, we present results for a low level approach by patching KVM to implement Xen´s live migration stop conditions, and a high level approach by monitoring the progress and service level state of a live migration and estimating the impact on the service level during the remaining migration time. We compare these approaches with an unpatched, vanilla KVM version and different sets of parameters used for live migration. Our service level management approaches offer superior QoS during migration. Especially, they allow to migrate also highly utilized VMs with comparably small influence on QoS.