System and method for accessing an offline storage unit through an online storage unit

摘要

By the same method as that of making data access to a data storage area in an online state, it is performed to access a data storage area other than the data storage area. A plurality of logical volumes carried by a disk array apparatus includes an online volume that is in an online state to a host and an offline state that is in an offline state to the host. The host transmits an access command including target information designating a target volume to the disk array apparatus as an access command to a starting volume other than the target volume. The disk array apparatus receives the access command to the starting volume and offers the data access to the target volume on the basis of the target information carried by that access command to the host.