Patent ID: 7467241
Filing Date: 2008-12-16
Classification: G06F

Abstract:
1. A storage control method, in which there are three or more storage systems comprises first, second and third storage systems, wherein said first storage system comprises a first volume which is a virtual logical volume, said second storage system comprises a second volume which is an actual volume and corresponds to said first volume, such that when said first storage system receives a write request designating said first volume, target data following the write request is transferred to said second storage system to be written in said second volume, and said third storage system comprises a third volume which is an actual volume, the storage control method comprising the steps of: (A) finding first and second paths for satisfying the following conditions (1) to (4) (2) said second volume is a copy source volume, (3) said third volume is a copy destination volume, (4) said third storage system having said copy destination volume is a copy destination storage system, and wherein said first path connects said first volume to said copy destination volume not via said copy source volume and said second path connects said first volume to said copy destination volume via said copy source volume, (B) selecting at least one path from said first and second paths; (C) receiving a write request designating said first volume; (D) executing an external connection processing for writing said write target data which follows said received write request to said copy source volume which corresponds to said first volume, or a remote copy processing for writing said write target data to be written in said first volume to said copy destination volume or a virtual volume which corresponds to said copy destination volume, such that said write target data is written to said copy source volume and to said copy destination volume via said selected path; wherein each storage system stores connection destination information, wherein said connection destination information includes an ID of a connection destination storage system which is a transmission destination of the write target data, and a connection type which indicates which one of the external connection processing and the remote copy processing is used to transmit the write target data to the connection destination storage system, and wherein based on said connection destination information of each storage system, said first and second paths are found in said step (A); and wherein in said step (A),