Patent ID: 8271991
Filing Date: 2012-09-18
Classification: G06F

Abstract:
1. A method of balancing a load in a computer system having at least one storage system coupled to a host computer, and a management computer coupled to the host computer and the at least one storage system, each of the at least one storage system having physical disks, which store data requested by the host computer to be written, and a disk controller, which controls the physical disks, the load balancing method comprising the steps of: setting, by the disk controller, at least one of the physical disks as a parity group; providing, by the disk controller, a storage area of the set parity group as at least one logical volume to the host computer; judging with the management computer, when a utilization ratio of the parity group becomes equal to or larger than a threshold; judging with the management computer the needs of an online migration for each and every of the at least one logical volume, choosing, by the management computer, as a data migration source volume, one of the logical volumes included in the parity group that has the utilization ratio equal to or larger than the threshold, by referring to the calculated logical volume online migration time, the data migration source volume being the logical volume from which data migrates.