A storage system comprises a router, which receives and transfers
commands; a plurality of RAID modules; and a switch, which receives
commands from the router and transmits the commands to any of the
plurality of RAID modules. Each RAID module comprises a plurality of
media drives, a RAID group is provided by the plurality of media drives.
Each RAID module comprises an independent RAID group which does not
extend into other RAID groups. In the storage system, the router performs
transfer of commands without performing analysis of commands, and a
processor within the RAID module performs command analysis.