Resource pool attributes
Just like VMs, resource pools can have shares, limits, and reservations specified:
shares – specify the relative priority of a resource pool’s access to a given resource. If an ESXi host comes under contention, resource pools with higher shares assigned will have higher priority, and therefore greater access, to the resource.
limits – specifies the maximum amount of a given resource that a resource pool can use. Examples are maximum consumption of CPU cycles or host physical memory.
reservations – specify the minimum amount of resources required by a resource pool (for example, the minumum amount of CPU that the pool must have).
There is one additional attribute specific to resource pools: the Expandable reservation attribute. It can be used to allow a resource pool that does not have the required resources to request resources from its parent or ancestors.