Patent ID: 8762672

Claim:
A storage system comprising: a physical device for storing data; a first storage apparatus that manages at least one first logical unit, the at least one first logical unit being correlated to a storage region of said physical device; a second storage apparatus that manages at least one second logical unit, the at least one second logical unit being correlated to said storage region of said physical device along with the first logical unit and recognized as being the same as the at least one first logical unit, wherein each of the first storage apparatus and the second storage apparatus are coupled to a host apparatus via a respective path; and wherein, said storage system has (1) a first status in which the host inputs/outputs data to/from the first storage apparatus and the second storage apparatus by switching between the first storage apparatus and the second storage apparatus, and (2) a second status in which either a respective path between the host apparatus and the first storage apparatus or a respective path between the host apparatus and the second storage apparatus is closed, and the host inputs/outputs data to/from either the first storage apparatus or the second storage apparatus over a respective path that is not closed.