Storage manager and storage management program

PROBLEM TO BE SOLVED: To provide a storage manager capable of performing copying relevant to a copy instruction under being processed using a newly activated storage unit 3 by using a correct logical unit number (LUN) even when a failover occurs.SOLUTION: When a storage unit 3 gets failed, a backup section 10 instructs to copy relevant to an operation volume of which processing is not succeeded by another storage unit 3 by specifying the LUNs of a copy source and a copy destination. Receiving a copy processing on the operation volume, a copy processing section 31 of the storage unit 3 executes the copy processing using the specified LUNs of the copy source and the copy destination. When an error is generated with the copy processing which is not relayed by another storage unit 3 due to an occurrence of a failover, the backup section 10 acquires two volumes of a copy pair and LUNs of the volume 6 constituting the cluster pair. The backup section 10 executes again the copy processing by using the acquired LUNs.SELECTED DRAWING: Figure 9