Disaster recovery codes
Kevin M. Greenan, Ethan L. Miller, Thomas Schwarz, Darrell D. E. Long · 2007
Large-scale storage systems need to provide the right amount of redundancy in their storage scheme to protect client data. In particular, many high-performance systems require data protection that imposes minimal impact on performance; thus, such systems use mirroring to guard against data loss. Unfortunately, as the number of copies increases, mirroring becomes costly and contributes relatively little to the overall system reliability. Compared to mirroring, parity-based schemes are space-efficient, but incur greater update and degraded-mode read costs. An ideal data protection scheme should perform similarly to mirroring, while providing the space efficiency of a parity-based erasure code.