Patent ID: 9098212
Filing Date: 2015-08-04
Classification: G06F

Abstract:
1. A computer system, which comprises a plurality of storage control apparatuses for providing a storage area to a computer, wherein each of the storage control apparatuses is mutually connected to the other storage control apparatuses, and each of the storage control apparatuses is configured to receive access commands from the computer, each of the storage control apparatuses comprising: a first logical storage area generated based on a physical storage area of a storage device managed by each relevant storage control apparatus of the plurality of storage control apparatuses; a virtually generated second logical storage area, which is associated with the first logical storage areas of the other storage control apparatuses; a pool for managing the first logical storage area and the second logical storage area: a plurality of virtual logical volumes virtually generated based on a logical storage area of the pool, the logical storage area having a specified size, which are assigned to either the first logical storage area or the second logical storage area each time new data is written by the computer: and a management unit configured to manage assignment management information for managing the logical storage area of the specified size assigned to a virtual logical volume of the plurality of virtual logical volumes, wherein each of the storage control apparatuses shares at least part of the assignment management information in common with the other storage control apparatuses, wherein the plurality of storage control apparatuses includes a first storage control apparatus and a second storage control apparatus configured to process the commands received from the computer, wherein, when the first storage control apparatus receives a read command for a virtual logical volume provided by the first storage control apparatus, the first storage control apparatus is configured to: wherein, when the second storage control apparatus receives the read command for a virtual logical volume provided by the second storage control apparatus, the second storage control apparatus is configured to: wherein each of the storage control apparatuses is configured to: wherein each of the storage control apparatuses is configured to: