Patent ID: 7430636
Filing Date: 2008-09-30
Classification: G06F,H04L

Abstract:
1. A storage system, comprising: a router which receives and transfers commands from an external device existing outside the storage system; a plurality of RAID modules; and a switch which transmits commands received from said router to any of said plurality of RAID modules, 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; memory that stores data received from said external device and data read from said logical unit via said switch; a processor which, according to a command received from said external device, writes data stored in said memory to said logical unit, or outputs data stored in said memory to said 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 unit 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 switch, wherein said switch transmits to said router 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 said router comprises a buffer, and even when said update request has been received, said router accepts commands from said external device, and upon receiving commands from said external device, said router accumulates the received commands in said buffer, and when updating of said transfer control information has ended, said router transfers commands accumulated in said buffer based on the updated transfer control information, and wherein said RAID group is provided independently so as not to extend into other RAID modules, wherein each of said plurality of RAID modules comprises configuration information representing an association between each logical unit ID and each media drive of the plurality of media drives, wherein 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 the 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 switch, and accesses a media drive associated with a specified media drive ID.