Patent ID: 7594083
Filing Date: 2009-09-22
Classification: G06F

Abstract:
1. A storage system, comprising: a first storage control device being configured to be coupled to at least a first one of a plurality of host computers and comprising a first controller and a second controller, both of the first controller and the second controller available to access a first plurality of logical volumes configured from a first portion of a first plurality of storage mediums of a first Redundant Array of Inexpensive Disks (RAID) group via a first path and available to access a second plurality of logical volumes configured from a second portion of the first plurality of storage mediums via a second path, the first controller responsible for writing data to the first plurality of logical volumes, the second controller responsible for writing data to the second plurality of logical volumes; and a second storage control device being configured to be coupled to at least a second one of the plurality of host computers and comprising a third controller and a fourth controller, both of the third controller and the fourth controller available to access a third plurality of logical volumes configured from a first portion of a second plurality of storage mediums of a second RAID group via a third path and available to access a fourth plurality of logical volumes configured from a second portion of the second plurality of storage mediums via a fourth path, the third controller responsible for writing data to the third plurality of logical volumes, the fourth controller responsible for writing data to the fourth plurality of logical volumes, wherein the first controller manages processor usage rate identifying usage rate of a processor in the first controller used for each of the first plurality of logical volumes on the logical volume basis, wherein, if the processor usage rate of a first logical volume of the first plurality of logical volumes is higher than a threshold, the first controller temporarily changes a responsible controller for writing data to the first logical volume to the second controller in the first storage control device for checking whether or not the change of the responsible controller for writing data to the first logical volume can be confirmed, and wherein the first controller, based on write execution of the second controller as the responsible controller, further temporarily changes the responsible controller for writing data to the first logical volume to the third controller in the second storage control device for checking whether or not the change of the responsible controller for writing data to the first logical volume can be confirmed.