Patent ID: 7539817
Filing Date: 2009-05-26
Classification: G06F,Y02D

Abstract:
1. A storage system comprising: a plurality of drive devices that 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 a logical disk on a given RAID group the logical disk having a logical storage area associated with the physical storage area of the given RAID group; a memory for storing a RAID group control table showing, for each RAID group, a power status of said each RAID group; wherein the storage system receives a request for creating a new logical disk, wherein the storage system preferentially selects a certain RAID group which is in a powered state from among the plurality of RAID groups based on the RAID group control table, wherein the storage system allocates some of the physical storage area of the certain RAID group to the new logical disk, and wherein when the storage system receives a write request for the new logical disk, the storage system stores data associated with the write request on the physical storage area that is allocated to the new logical disks, wherein a primary RAID group having a largest free capacity in the powered state is selected as the certain RAID group, wherein when the largest free capacity is larger than a requested capacity of the new logical disk, the entire physical storage area of the selected primary RAID group is allocated to the new logical disk.