From David Floyer at Wikibon, 10.24.11
"The biggest big data systems are now object based rather than file based. One key advantage of object storage is that the data and metadata are stored together, which eliminates many of the locking, metadata traversals, directory crawling, and file allocation table issues of traditional file systems -- (MP - let me add maintenance of "authenticity" to that list as well) . For example, Google claims that the Google Megastore achieves 3 billion writes and 20 billion reads per day. As of Q2 2011, theAmazon S3 system stores about half a trillion objects and reads a peak of 290,000 0bjects per second (25 billion per day).
DataDirect Networks (DDN) have introduced a WOS 2.0 (Web Object Scaler) object storage system which they claim delivers up to 55 billion small object reads and 25 billion writes/day. This is twice as many as the Amazon S3 system and twenty times the throughput of the DARPA system."