Patent ID: 9092142
Filing Date: 2015-07-28
Classification: G06F

Abstract:
1. A storage system coupled to a host computer, comprising: a first storage apparatus including a first logical volume associated with a virtual volume, and configured to provide the first logical volume to the host computer as the virtual volume; and a second storage apparatus being coupled to the first storage apparatus, having a second logical volume associated with the virtual volume, and configured to provide the second logical volume to the host computer as the virtual volume, wherein the first storage apparatus, when receiving a first write request for the virtual volume, is capable of performing a processing for the first write request by one of a first write processing method and a second write processing method, wherein the first storage apparatus is configured to process the first write processing method by which a processing of storing write data relating to the first write request in the first logical volume is executed as well as the first write request is transferred to the second storage apparatus to store the write data in the second logical volume in the second storage apparatus, wherein the first storage apparatus is configured to process the second write processing method by which the first write request is transferred to the second storage apparatus to store the write data in the second logical volume in the second storage apparatus without executing the processing of storing the write data in the first logical volume, and wherein the first storage apparatus is configured to acquire a first IO load for a predetermined area of the virtual volume in the first storage apparatus, and a second IO load for the predetermined area of the virtual volume in the second storage apparatus;, select either the first write processing method or the second write processing method by comparing the first IO load and the second IO load with a threshold; and perform a processing for the first write request using the selected processing method.