Dynamic storage area allocation method for replicated data and computer system with multiple storage devices

摘要

The invention relates to transfer of data and replication of data among several storage devices that is executed without imposing a load on the computer connected to the storage system. For example, a first host computer 10 monitors usage rates of transfer groups TG11, TG12 and physical path usage rate on a storage device interconnect physical path 50, and when either a usage rate or physical path usage rate goes above a predetermined value, issues to the first storage device 20 an instruction to allocate a reserved volume R11, R12. The first host adaptor 21 receiving the reserved volume R11, R12 allocation request allocates reserved volume R11 to transfer group TG1, whereby a virtual transfer volume is formed by transfer volume T11 and the reserved volume R11 allocated thereto. As a result, capacity of the virtual transfer volume is increased by the equivalent of the reserved volume R11 capacity, so that additional transfer frames may be stored.