Patent ID: 7747819
Filing Date: 2010-06-29
Classification: G06F,H04L

Abstract:
1. A storage system, comprising: a plurality of routers which each receive and transfer commands from an external device existing outside the storage system; a plurality of RAID (Redundant Array of Independent Disks) modules; and at least one switch which transmits commands received from said plurality of routers to any of said plurality of RAID modules, wherein said plurality of routers are connected to the plurality of RAID modules via said at least one switch, wherein each RAID module comprises: a plurality of media drives; a logical unit in accordance with a RAID group provided by said plurality of media drives; a first memory that stores data received from said external device and data read from said logical unit via said at least one switch; a processor which, according to a command received from said external device, writes data stored in said first memory to said logical unit, or outputs data stored in said first memory to said at least one switch; a control program, wherein said control program provides storage virtualization functions; and a storage resource that stores logical unit IDs which represent each of a plurality of logical units existing in the RAID module, and, when there is an update of a logical unit ID in said storage resource, said storage resource transmits an update request and a logical unit ID related to the update to said at least one switch, wherein said at least one switch transmits to a router of said plurality of routers said update request and said logical unit ID related to said request, wherein said router receives said update request and said logical unit ID related to the update, and uses said received logical unit ID to update a transfer control information according to said update request, wherein each of said plurality of routers comprises: at least one protocol chip that performs protocol conversion of commands transmitted to or from each of said plurality of routers; and a buffer, and even when said update request has been received, each of said plurality of routers accepts commands from said external device, and upon receiving commands from said external device, each of said plurality of routers accumulates the received commands in said buffer, and when updating of said transfer control information has ended, each of said plurality of routers transfers commands accumulated in said buffer based on the updated transfer control information, wherein said RAID group is provided independently so as not to extend into other RAID modules, wherein each RAID module has an independent RAID configuration such that each RAID module is independent of other of said plurality of RAID modules, wherein in said independent RAID configuration, each of said plurality of RAID modules comprises configuration information that is specific to itself, wherein said configuration information provides an association between each logical unit ID and each media drive of the plurality of media drives, wherein said configuration information of each of said plurality of RAID modules comprises respective IDs of logical units and media drives existing in the RAID module comprising said configuration information, and does not comprise the respective IDs of logical units and media drives existing in other RAID modules, and wherein said processor specifies from said configuration information a media drive ID associated with a logical unit ID received from said at least one switch, and accesses a media drive associated with a specified media drive ID.