DNBD (Distributed Network Block Device) is a read-only and caching network block device specially developed with stateless/diskless Linux client operation in mind. See more on stateless Linux at OpenSLX. DNBD supports following main features: * Replication of servers for robustness * Multicast communication and caching of network traffic for scalability These characteristics make it suitable especially for use in wireless networks, e.g. for diskless/stateless clients or to share multimedia files in such an environment. The servers can export a file or block device equipped with a operating system, movies, music, etc. Several clients can import the block device and access it like a local hard disk. However, each block transfer over the network can be cached by all clients: If several users on each client start to watch a movie within a certain time interval, the movie data has to be transmitted only once (depending on the cache size).