(2) GFS (Google File System) maintains high availability through faster recovery, chunk and master replication. Both the master and chunk server can restore their states and restart in seconds. Every chunk of data is replicated on multiple chunk servers.
Operation log and checkpoints are owned by the master, and are replicated on multiple machines.
GFS supported BigTable provides the data storage backbone for several services such asWeb indexing, Google Earth, Google Finance, Google Reader, YouTube and Gmail