Patent ID: 7543129
Filing Date: 2009-06-02
Classification: G06F

Abstract:
1. A storage system comprising a storage device unit constituted by a plurality of disk devices for storing data, and a control unit for controlling input/output said data as requested by a host computer, wherein the control unit configures the disk devices into a plurality of logical volumes each with a logical volume identification number, an emulation slot type, a logical volume size, and an allocation unit size, the plurality of logical volumes include at least two different allocation unit sizes, the control unit receives a pool area generation command and configures a plurality of pool areas each of which includes some of the logical volumes that have an identical emulation slot type and an identical allocation unit size, the control unit generates a virtual logical volume in response to a virtual logical volume generation command which includes information of a virtual logical volume size of the virtual logical volume, and allocates one of the pool areas to the virtual logical volume, and in response to a write request addressed to the virtual logical volume, the control unit, if no unused storage area available in said one of the pool areas allocated to the virtual logical volume, selects one of the pool areas that has an allocation unit size closest to a size of write target data of the write request, selects an unused storage area in one of the logical volumes belonging to the selected pool area, and writes the write target data into the selected unused storage area.