Patent ID: 8266475

Claim:
A storage management device that manages data storage devices storing user data, and one or more spare storage devices used when a failure occurs in any of the data storage devices, the storage management device comprising: a group management unit that divides the data storage devices into groups and that implements at least one of the distribution and the redundancy of the user data between the data storage devices belonging to the same group; a data storage device restoration processor that, on the occurrence of a failure in any of the data storage devices, assigns the one or more spare storage devices as a replacement for the failed data storage device; and a configuration change processor that performs configuration change processing of the group to which the data storage devices belong, wherein the configuration change processor comprises: a spare storage device securing unit that secures the one or more spare storage devices; a change processing redundancy implementing unit that writes data concerning the configuration change processing of the group into the one or more spare storage devices secured by the spare storage device securing unit; and a change processing/restoration processor that, if the configuration change of the group is interrupted, performs continuation of the configuration change of the group, or restoration of the group to its state before the start of the change, using the data written into the one or more spare storage devices.