About VMware Distributed Resource Scheduler
VMware Distributed Resource Scheduler (DRS) is a utility that balances computing workloads with available resources in a virtualized environment. DRS dynamically allocates the available resources among VMs based on predefined rules called VM affinity rules. These rules are defined at the cluster level. When a VM experiences an increased load, DRS automatically allocates additional resources by redistributing VMs among the physical servers in the resource pool. In addition to VM affinity rules, the placement of VMs across the cluster is based on vMotion compatibility. vMotion has its own set of requirements to move the VMs across the hosts. For example, if a VM that has a local network (not connected to any physical adapter), it cannot be moved using VMotion.