A method and apparatus are provided for detecting and correcting various data errors that may arise in a mass data storage apparatus comprising a set of physical mass storage devices operating as one or more larger logical mass storage devices. More particularly, there is provided a method...http://www.google.com.au/patents/US5758054?utm_source=gb-gplus-sharePatent US5758054 - Non-volatile memory storage of write operation identifier in data storage device 
