In one embodiment, a user or client device is connected to a distributed file system comprised of one or more physical nodes. The data on each of the physical nodes store metadata about files and directories within the file system. Some of the embodiments permit a user to take a snapshot of data stored...http://www.google.com.hk/patents/US7680836?utm_source=gb-gplus-share專利 US7680836 - Systems and methods for a snapshot of data
