HIERARCHICAL SECONDARY RAID STRIPE MAPPING

摘要

Methods and apparatus of the present invention include new data and parity mapping for a two-level or hierarchical secondary RAID architecture. The hierarchical secondary RAID architecture achieves a reduced mean time to data loss compared with a single-level RAID architecture. The new data and parity mapping technique provides load-balancing between the disks in the hierarchical secondary RAID architecture and facilitates sequential access.