Disclosed is a system for altering the structure of parity groups, e.g., altering the RAID level or number of storage devices included in the RAID array. A parity group consists of a set of data blocks and parity data for the data blocks. The data and parity data are stored in at least two storage devices....http://www.google.de/patents/US6279138?utm_source=gb-gplus-sharePatent US6279138 - System for changing the parity structure of a raid array
