With the DRS rules configured, the distributed resource scheduler will apply the rules when determining the placement of virtual machines when they are powered on or when migrating virtual machines to other hosts to balance cluster resource usage.

When an affinity rule has been configured to keep several virtual machines together, if DRS migrates one of the virtual machines in the rule, all of the virtual machines that are configured will also be migrated to the new host. When an anti-affinity rule has been configured to keep virtual machines separated, DRS will not migrate a virtual machine to a host running another virtual machine that's been configured in the rule.