Provided are RAID storage systems, methods, and controllers for RAID storage systems. A first method includes storing a first copy of the data in a first RAID array corresponding to a first RAID level providing redundancy (such as RAID-5), and storing a second copy of the data in a second RAID array...http://www.google.de/patents/US7506187?utm_source=gb-gplus-sharePatent US7506187 - Methods, apparatus and controllers for a raid storage system
