Patent ID: 7571356

Claim:
A storage control device, comprising: a host communication control unit which controls communication with a host device; a subordinate communication control unit which controls communication with a plurality of storage devices configured into a plurality of RAID groups for storing data and parity; and a plurality of connection control units each of which connects a different set of said storage devices and said subordinate communication control unit, each set of said storage devices containing one and only one storage device of each of the RAID groups; wherein said each connection control unit comprises a plurality of switching circuits which are connected to said different set of said storage devices via a plurality of communication ports, a control circuit which is connected to each of said switching circuits, and an error monitoring unit which monitors error information for each of said storage devices, said plurality of switching circuits in said each connection control unit are connected to one another either in series, or with one said plurality of switching circuits as a central hub having the remaining switching circuits connected thereto, or in a ring shape, said error monitoring unit comprises: error information collection units, provided within said switching circuits respectively, which detect errors respectively occurring at said communication ports of said switching circuits, and store the errors as error information; an intermediate storage unit, provided within said control circuit, which reads out and stores said error information stored in said error information collection units at respective predetermined timings; and an error information transmission unit, provided within said control circuit, which transmits said error information stored in said intermediate storage unit to said subordinate communication control unit in response to a request from said subordinate communication control unit, when detecting a predetermined type of error which is set as highly urgent, said error monitoring circuit notifies the subordinate communication control unit that the predetermined type of error is detected, and when detecting an error other than the predetermined type of error, the error information collection unit stores the detected error as error information and transmits the error information according to the request from the subordinate communication control unit.