Hadoop Distributed File System
From Just Solve the File Format Problem
Hadoop Distributed File System is a network file system connected with the Apache Hadoop project. It's sometimes sneeringly referred to as a "data store" rather than a true "file system" due to its lack of POSIX compliance (POSIX is a set of operating system standards mostly connected with Unix-style systems), but the concept of file systems predates POSIX and is not tied to one set of standards. It was in part based on Google File System.
