Cluster-type storage system and managing method of the cluster-type storage system

A storage system comprising:

• plural first protocol transformation units that include interfaces with an external device and transform, to a protocol within the system, a read-write protocol of data exchanged with the external device;
• plural disk devices;
• plural second protocol transformation units that include interfaces with the disk devices and transform, to the protocol within the system, a read-write protocol of data exchanged with the disk devices;
• plural cache control units that include cache memories storing data read/written with respect to the disk devices and control the cache memories;
• a first interconnection network connecting the first protocol transformation units and the cache control units;
• and
• a system management unit, wherein
• the plural cache control units and the plural second protocol transformation units are divided into plural control clusters where a single control cluster includes an optional number of the cache control units and the second protocol transformation units,
• the cache control units and the second protocol transformation units are interconnected in the control clusters by a second interconnection network in the control clusters,
• only data stored in the plural disk devices connected to the second protocol transformation units in the control clusters is stored in the cache memories of the cache control units in the control clusters,
• control of the cache memories and management of storage regions of the plural disk devices are independent inside the control clusters, and
• the system management unit manages, as a single system, the plural first protocol transformation units and the plural control clusters, wherein
• the first interconnection network is divided into a third interconnection network that transfers data read/written with the external device and a fourth interconnection network that transfers control information for managing the storage system, and
• the system management unit is connected to the fourth interconnection network.

A storage system comprising:

• plural protocol transformation units that include interfaces with an external device and transform, to a protocol within the system, a read/write protocol of data exchanged with the external device;
• plural cache control units that include cache memories storing data read/written with the external device and control the cache memories;
• and
• an interconnection network that connects the protocol transformation units and the cache control units, wherein
• the plural cache control units are divided into plural control clusters, at least a first control portion of the plural cache control units are in a first control cluster and a second control portion of the plural cache control units are in a second control cluster, and the cache memories in the plural cache control units are logically managed in the storage system as a single cache memory so that each said protocol transformation unit can access each said cache memory of each cache control unit.