vSphere 6.7 introduces a new two-pass algorithm to allocate a resource pool’s resource reservation to its children (also known as divvying).
VMware vSphere Distributed Resource Scheduler (DRS), a utility that balances computing workloads with available resources, uses this new two-pass algorithm to allocate a resource pool’s reservation to its child virtual machines. In the first pass, the resource pool reservation is distributed and capped at the virtual machines’s demand, subject to each virtual machine’s fair share. In the second pass, excess reservation is distributed proportionally, capped at the virtual machine’s configured size. Therefore, resource pool reservation is aggressively allocated to its children, giving more buffer to sudden virtual machine demand spikes.