Patent attributes
A storage system connected to a terminal, the computer system includes: a plurality of drive devices that respectively drive a plurality of physical disks each having a physical storage area; a RAID configuration unit that configures a plurality of RAID groups by grouping two or more of the plurality of physical disks; a logical disk creation unit that creates, for the terminal through the RAID group, a logical disk having a logical storage area associated with the physical storage area; a memory for storing a RAID group control table showing, for each the RAID group, (i) a free capacity that is the amount of physical storage area remaining in the RAID group to be able to be associated with the logical disk and (ii) a power status of the RAID group; a receiver that receives a request for creating a new logical disk; and an area allocation unit that allocates to the new logical disk the physical storage area remaining in the RAID group selected by giving priority to a RAID group in a powered state over a RAID group in a non-powered state with reference to the RAID group control table.