The bandwidth of the inter-connection network between the clusters is quite narrower than that of the inter-connection network in the clusters. When the logical allocation technique is simply applied to a cluster storage system, there is created a logical partition associated with two or more clusters. It is not possible to create logical partitions of performance corresponding to resources allocated thereto. In a storage system including a first cluster and a second cluster, when a resource of the storage system is logically subdivided into logical partitions, a resource of the first cluster is allocated to one logical partition. The system may be configured such that the first and second clusters are connected via switches to disk drives. The system may also be configured such that when failure occurs in the first cluster, the second cluster continuously executes processing of the first cluster.