Openstack-swift object server.
swift-object-server [CONFIG] [-h|--help] [-v|--verbose]
The Object Server is a very simple blob storage server that can store, retrieve and delete objects stored on local devices. Objects are stored as binary files on the filesystem with metadata stored in the file's extended attributes (xattrs). This requires that the underlying filesystem choice for object servers support xattrs on files. Some filesystems, like ext3, have xattrs turned off by default. Each object is stored using a path derived from the object name's hash and the operation's timestamp. Last write always wins, and ensures that the latest object version will be served. A deletion is also treated as a version of the file (a 0 byte file ending with ".ts", which stands for tombstone). This ensures that deleted files are replicated correctly and older versions don't magically reappear due to failure scenarios.
More in depth documentation in regards to swift-object-server and also about Openstack-Swift as a whole can be found at http://swift.openstack.org/index.html and http://docs.openstack.org