Patent ID: 8370572

Claim:
A storage system comprising: a plurality of first disk devices; a plurality of second disk devices, in which a lifetime of the plurality of second disk devices is different from a lifetime of the plurality of first disk devices; and a controller coupled to the plurality of first disk devices and the plurality of second disk devices, wherein the controller configures a first logical unit by the plurality of first disk devices and a second logical unit by the plurality of second disk devices, provides the first and the second logical units to a host computer, and manages a first remaining available time of the first logical unit and a second remaining available time of the second logical unit, on a logical unit basis, wherein the controller detects information of the lifetime of each of the plurality of first disk devices from the plurality of first disk devices and information of the lifetime of each of the plurality of second disk devices from the plurality of second disk devices, and manages the first remaining available time and the second remaining available time based on the detected information, wherein the controller sets a minimum value of remaining lifetime values among the plurality of first storage disks as the first remaining available time and sets a minimum value of remaining lifetime values among the plurality of second storage disks as the second remaining available time, and wherein the lifetime is a time serving as a criterion for requiring a disk change, and the remaining lifetime is a time remaining after subtracting an accumulated active time from the lifetime.