{{Distinguish, Distributed File System (Microsoft)
The DCE Distributed File System (DCE/DFS)"File Systems in a Distributed Computing Environment" Open Software Foundation, July 1991 is the remote file access protocol used with the
Distributed Computing Environment
In computing, the Distributed Computing Environment (DCE) software system was developed in the early 1990s from the work of the Open Software Foundation (OSF), a consortium (founded in 1988) that included Apollo Computer (part of Hewlett-Packard fr ...
. It was a variant of
Andrew File System
The Andrew File System (AFS) is a distributed file system which uses a set of trusted servers to present a homogeneous, location-transparent file name space to all the client workstations. It was developed by Carnegie Mellon University as part of ...
(AFS), based on the AFS Version 3.0 protocol that was developed commercially by
Transarc
Transarc Corporation was a private Pittsburgh-based software company founded in 1989 by Jeffrey Eppinger, Michael L. Kazar, Alfred Spector, and Dean Thompson of Carnegie Mellon University.
Transarc commercialized the Andrew File System (AFS), ...
Corporation. AFS Version 3.0 was in turn based on the AFS Version 2.0 protocol (also used by the Coda disconnected file system) originally developed at Carnegie Mellon University.
DCE/DFS consisted of multiple cooperative components that provided a network file system with strong file system semantics, attempting to mimic the behavior of
POSIX
The Portable Operating System Interface (POSIX) is a family of standards specified by the IEEE Computer Society for maintaining compatibility between operating systems. POSIX defines both the system- and user-level application programming inter ...
local file systems while taking advantage of performance optimizations when possible. A DCE/DFS client system utilized a locally managed cache that would contain copies (or regions) of the original file. The client system would coordinate with a server system where the original copy of the file was stored to ensure that multiple clients accessing the same file would re-fetch a cached copy of the file data when the original file had changed.
The advantage of this approach is that it provided very good performance even over slow network connections because most of the file access was actually done to the local cached regions of the file. If the server failed, the client could continue making changes to the file locally, storing it back to the server when it became available again.
DCE/DFS also divorced the concept of logical units of management (
Fileset
In computing, a fileset is a set of computer files linked by defining property or common characteristic. There are different types of fileset though the context will usually give the defining characteristic. Sometimes it is necessary to explici ...
s) from the underlying volume on which the fileset was stored. In doing this it allowed administrative control of the location for the fileset in a manner that was transparent to the end user. To support this and other advanced DCE/DFS features, a local journaling file system (DCE/LFS also known as
Episode
An episode is a narrative unit within a larger dramatic work or documentary production, such as a series intended for radio, television or streaming consumption.
The noun ''episode'' is derived from the Greek term ''epeisodion'' (), meaning th ...
) was developed to provide the full range of support options.
IBM has not maintained it since 2005: https://web.archive.org/web/20071009171709/http://www-306.ibm.com/software/stormgmt/dfs/
IBM was working on a replacement for DCE/DFS calle ADFS (Advanced Distributed File System). One major goal of this project was to decouple DFS from the complexities of DCE's cell directory services (CDS) and security services (secd). Another key feature would have been the elimination of enctype limitations associated with DCE/RPC. No public mention of this effort has been made since 2005, leading many to believe the project has been killed.
The DCE Distributed File System (DFS) was adopted by the
Open Software Foundation
The Open Software Foundation (OSF) was a not-for-profit industry consortium for creating an open standard for an implementation of the operating system Unix. It was formed in 1988 and merged with X/Open in 1996, to become The Open Group.
Despit ...
in 1989 as part of their
Distributed Computing Environment
In computing, the Distributed Computing Environment (DCE) software system was developed in the early 1990s from the work of the Open Software Foundation (OSF), a consortium (founded in 1988) that included Apollo Computer (part of Hewlett-Packard fr ...
.
See also
*
Andrew File System
The Andrew File System (AFS) is a distributed file system which uses a set of trusted servers to present a homogeneous, location-transparent file name space to all the client workstations. It was developed by Carnegie Mellon University as part of ...
*
Distributed Computing Environment
In computing, the Distributed Computing Environment (DCE) software system was developed in the early 1990s from the work of the Open Software Foundation (OSF), a consortium (founded in 1988) that included Apollo Computer (part of Hewlett-Packard fr ...