Patent ID: 7587553

Claim:
A storage controller, which provides a host device with a logical volume accessed by the host device, comprising: a plurality of storage drives; a plurality of physical storage devices which are formed by grouping physical storage regions provided in each of the storage drives; a plurality of logical storage devices, at least one or more of which are set in a physical storage region provided in each of the physical storage devices; and a control section which associates a plurality of predetermined logical storage devices of the logical storage devices with the logical volume; and wherein the control section selects the physical storage devices to which the plurality of predetermined logical storage devices are allocated, in accordance with whether the type of access pattern is random access or sequential access when the host device accesses the logical volume, and in accordance with a first performance indicator which is set in the logical volume beforehand; and further wherein the control section selects the physical storage devices to which the plurality of predetermined logical storage devices are allocated, in accordance with the type of access pattern for each preset predetermined time zone and the first performance indicator; and (1) when the access pattern is the random access, the control section: (1-1) computes the second performance indicator by dividing the first performance indicator by the number of the predetermined logical storage devices configuring the logical volume; and (1-2) computes, for each of the predetermined logical storage devices in the each predetermined time zone, the total value of the second performance indicators as the third performance indicator for the case where the predetermined logical storage devices are allocated to the physical storage devices, and (2) when the access pattern is the sequential access, the control section: (2-1) sets the first performance indicator as the second performance indicator; (2-2) sets, for each of the predetermined logical storage devices in the each predetermined time zone, the value of the second performance indicator as the third performance indicator for the case where the predetermined logical storage devices are allocated to the physical storage devices; and (3) selects the physical storage devices to which the plurality of predetermined logical storage devices are allocated, for each of the plurality of predetermined logical storage devices so that variances of the third performance indicators become minimum.