Embodiments of the present invention are directed to methods and systems of storing data in storage volumes while ensuring data matching between the storage volumes. In one embodiment, a system for storing data comprises a first storage area to store data; a second storage area to store data; a first...http://www.google.com.hk/patents/US20040128453?utm_source=gb-gplus-share專利 US20040128453 - Storage system
