US Patent 7836017 File replication in a distributed segmented file system

A system includes storage configured to store file system entities, including directories and files, residing in segments of a distributed, segmented single file system, file servers configured to implement the single file system with separate ones of the file servers controlling metadata of separate ones of the segments, and a controller configured to control storage of files in the file system such that for a master file stored in a first segment, a first replica of the master file will be stored in a second segment that is physically separate from the first segment, the controller being further configured to control storage of directories in the file system such that a single directory will include identifiers for the master file and the first replica.