METHOD FOR MONITORING OF DATA LOSS OF HIERARCHICAL DATA STORAGE DEVICE

摘要

PROBLEM TO BE SOLVED: To selectively trace data loss areas in stored data by monitoring data losses in first and second regions in the RAID area of a hierarchical data storage device having a plurality of storage discs. SOLUTION: A physical storage space is mapped in a first virtual storage space representing a physical space as a plurality of RAID areas for storing data in accordance with various RAID levels (200) and the first virtual storage space is mapped in a second virtual storage space representing a physical storage space as a plurality of virtual blocks (202). Then the RAID areas are classified as the optimum (204) and the RAID areas are monitored for detecting the loss of storage data (206). When a data loss is detected in the first region of the RAID areas, the first region is marked as invalid (21) and the region is classified as deteriorated (214). When a data loss is detected in the second region of the RAID areas, the invalid region is informed as disabled.