In cluster setups, Distributed Resource Scheduler (DRS) can assist you with automatic balancing CPU and storage load (Storage DRS). DRS monitors the ESXi hosts in a cluster and migrates running VMs using vMotion, primarily, to ensure that all the VMs get the resources they need. Secondarily, it tries to balance the cluster. In addition to this, Storage DRS monitors shared storage for information about latency and capacity consumption. In this case, Storage DRS recognizes the potential to optimize storage resources, it will make use of Storage vMotion to balance the load. We will cover Storage DRS in detail later in this book.
DRS primarily uses two metrics to determine the cluster balance: