Patent ID: 8463995
Filing Date: 2013-06-11
Classification: G06F

Abstract:
1. A storage system comprising: a first storage control unit that comprises one or more first controllers for controlling data received from a higher-level device and addressed to one or more first logical units; and a second storage control unit that comprises one or more second controllers for controlling data received from the first storage control unit and addressed to one or more second logical units, and a plurality of first storage mediums for storing the data in accordance with the control of one of the second controllers, wherein the first storage control unit exercises control so as to manage a tier level of the one or more first logical units in accordance with a performance of the second controllers, and to send the data received from the higher-level device, and addressed to the one or more first logical units to the one or more second logical units in accordance with processing by an application of a type suitable for the tier level of the first logical unit, wherein in a first coupling mode, the one or more first controllers are serially coupled to each other via a first type coupling medium, wherein in a second coupling mode, at least one of the first storage control unit and the second storage control unit are coupled to an external storage control unit via a second type coupling medium, such that when the first storage control unit is coupled to the external storage control unit, the one or more first logical units virtualize one or more logical units of the external storage control unit, and when the second storage control unit is coupled to the external storage control unit, the one or more second logical units virtualize the one or more logical units of the external storage control unit, wherein in a third coupling mode, the first storage control unit and the second storage control unit are coupled by the second type coupling medium, such that the one or more first logical units virtualize the one or more second logical units, wherein the tier level is determined according to whether the first storage control unit and the second storage control unit are coupled in the first, second or third coupling modes.