A method, system and apparatus of a file locking within a network file system federated namespace is disclosed. In one embodiment, a method includes accessing a target file in a storage medium over a network through an intermediate proxy server using a processor. The storage medium may be any one storage medium of a group of storage mediums on the network forming a data sharing cluster. In addition, the method includes locking the target file in the storage medium through a lock protocol to enable an access to modify the target file to at most one user at any given time, via the intermediate proxy server.