Patent ID: 7937542

Claim:
A storage controller, comprising: a controller for receiving a read command and a write command from a host system; and a plurality of storage devices connected to said controller and from which data is read or to which data is written based on the control of said controller; wherein said controller includes a logical sub-block setting unit for setting logical sub-block units in which an additional code containing a guarantee code is added to user data, and an additional code length setting unit capable of changing the code length of said additional code in accordance with a performance request including transaction performance and sequential access performance, and accesses said storage devices in said logical sub-block units containing an additional code of a code length set with said additional code length setting unit; wherein said storage devices process the access from said controller in physical sub-block units; wherein said logical sub-block units and said physical sub-block units are of a different block size; and wherein said controller processes the access to and from said storage devices in a specific block size configured from a least common multiple of said logical sub-blocks and said physical sub-blocks.