Patent ID: 7124242

Claim:
A volume providing system which provides at least one of a plurality of logical volumes, wherein the plurality of logical volumes are prepared on two or more physical disks, and include a copying source volume that acts as a data copying source, and a copying destination volume that acts as a data copying destination, said two or more physical disks include one or more first physical disks, and one or more second physical disks that are separate from said first physical disks, said copying source volume is disposed on said one or more first physical disks, said copying destination volume is disposed on said one or more second physical disks, said volume providing system comprises a memory region that stores one or more computer programs, and one or more processors that read out at least one of said one or more computer programs from said memory region, and that perform processing in accordance with said read-out computer program, and said one or more computer programs of said volume providing system include a target program that receives the provision of logical volumes, one or more volume interface programs that provide an interface for logical volumes to said target program, and one or more volume filter programs that select one logical volume from said copying source volume and said copying destination volume, and provide said selected logical volume to said target program via said one or more volume interface programs; and wherein at least one of said one or more processors prepares a copying source stack corresponding to said copying source volume, and prepares a copying destination stack corresponding to said copying destination volume, a first volume interface program and first volume filter program corresponding to said copying source volume are called up in said copying source stack, a second volume interface program and second volume filter program corresponding to said copying destination volume are called up in said copying destination stack, a logical volume is provided to said target program via said first volume filter program, and said second volume filter program is hidden with respect to said target program, in cases where said copying source volume is provided to said target program, said copying source volume is provided to said target program from said first volume filter program via said first volume interface program, and in cases where said copying destination volume is provided to said target program, said copying destination volume is provided to said target program from said second volume filter program via said first volume filter program, and from said first volume filter program via said first volume interface program.