5.7. Load Balancing Policy: InClusterUpgrade

The InClusterUpgrade scheduling policy distributes virtual machines based on host operating system version. Hosts with a newer operating system than the virtual machine currently runs on are given priority over hosts with the same operating system. Virtual machines that migrate to a host with a newer operating system will not migrate back to an older operating system. A virtual machine can restart on any host in the cluster. The policy allows hosts in the cluster to be upgraded by allowing the cluster to have mixed operating system versions. Preconditions must be met before the policy can be enabled. See Upgrading Hosts in a Cluster from Red Hat Enterprise Linux 6 to Red Hat Enterprise Linux 7 in the Red Hat Enterprise Virtualization 3.6 Upgrade Guide.