The main goal of resource control in Virtuozzo Containers 4.0 is to provide service level management for Containers. Because of Hardware Node resources being shared by its Containers, correctly configured resource control settings prevent serious impacts resulting from the resource over-usage (accidental or malicious) of any Container on the other Containers. Using resource control parameters for service level management also allows to enforce fairness of resource usage among Containers and better service quality for preferred Containers, if necessary.