The LocalStorageCapacityIsolation feature added a new resource type
ResourceEphemeralStorage "ephemeral-storage" so that this resource can
be allocated, limited, and consumed as the same way as CPU/memory. All
the features related to resource management (resource request/limit, quota, limitrange) are avaiable for local ephemeral storage.

This local ephemeral storage represents the storage for root file system, which will be consumed by containers' writtable layer and logs. Some volumes such as emptyDir might also consume this storage.