|Open Group Technical Standard|
|Protocols for Interworking: XNFS, Version 3W|
|Document Number: C702|
©February 1998, The Open Group All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the copyright owners.
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The Open Group is the leading vendor-neutral, international consortium for buyers and suppliers of technology. Its mission is to cause the development of a viable global information infrastructure that is ubiquitous, trusted, reliable, and as easy-to-use as the telephone. The essential functionality embedded in this infrastructure is what we term the IT DialTone. The Open Group creates an environment where all elements involved in technology development can cooperate to deliver less costly and more flexible IT solutions.
Formed in 1996 by the merger of the X/Open Company Ltd. (founded in 1984) and the Open Software Foundation (founded in 1988), The Open Group is supported by most of the world's largest user organizations, information systems vendors, and software suppliers. By combining the strengths of open systems specifications and a proven branding scheme with collaborative technology development and advanced research, The Open Group is well positioned to meet its new mission, as well as to assist user organizations, vendors, and suppliers in the development and implementation of products supporting the adoption and proliferation of systems which conform to standard specifications.
With more than 200 member companies, The Open Group helps the IT industry to advance technologically while managing the change caused by innovation. It does this by:
The Open Group operates in all phases of the open systems technology lifecycle including innovation, market adoption, product development, and proliferation. Presently, it focuses on seven strategic areas: open systems application platform development, architecture, distributed systems management, interoperability, distributed computing environment, security, and the information superhighway. The Open Group is also responsible for the management of the UNIX trademark on behalf of the industry.
This process includes the identification of requirements for open systems and, now, the IT DialTone, development of Technical Standards (formerly CAE and Preliminary Specifications) through an industry consensus review and adoption procedure (in parallel with formal standards work), and the development of tests and conformance criteria.
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There are several types of specification:
The Open Group Technical Standards form the basis for our Product Standards. These Standards are intended to be used widely within the industry for product development and procurement purposes.
Anyone developing products that implement a Technical Standard can enjoy the benefits of a single, widely supported industry standard. Where appropriate, they can demonstrate product compliance through the Open Brand. Technical Standards are published as soon as they are developed, so enabling vendors to proceed with development of conformant products without delay.
CAE Specifications and Developers' Specifications published prior to
January 1998 have the same status as Technical Standards (see above).
Preliminary Specifications have usually addressed an emerging area of technology and consequently are not yet supported by multiple sources of stable conformant implementations. They are published for the purpose of validation through implementation of products. A Preliminary Specification is as stable as can be achieved, through applying The Open Group's rigorous development and review procedures.
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before its progression to becoming a Technical Standard. While
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corresponding Technical Standards, the ability to do so depends
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This document describes XNFS, the X/Open NFS Specification. This document supersedes the previous X/Open publication Protocols for X/Open Interworking, XNFS, Version 3, Document Number C525, August 1996. The previous version was aligned with Sun's NFS Version 3 (RFC 1813). This revised version (XNFS, Version 3W) incorporates the Sun WebNFSTM; optional extensions (RFCs 1738, 1808, 2054, 2055).
The process of accessing remote files and directories as though they were part of the local file system hierarchy is commonly known as "transparent file access" (TFA). The most widely used heterogeneous TFA architecture is the Network File System (NFS), originally developed by Sun Microsystems.
XNFS provides a means of access to files and directories that are physically stored on remote systems, by extending the semantics of local system interfaces so that applications and end users can (as far as possible) ignore the distinctions between local and remote objects.
NFS has been implemented on a wide range of architectures, from personal computers to mainframes and supercomputers. The specifications for the protocols associated with NFS have been published, and there have been several independent implementations.
With the XNFS specification, X/Open offers the market a temporary but complete solution to the problem of transparent file access between X/Open-compliant systems. Temporary, because X/Open recognises the TFA standardisation effort ongoing within the IEEE P1003.1f committee, and X/Open intends to be compliant with 1003.1f TFA at such time as it becomes an IEEE standard. Complete, because X/Open now offers both protocols for interoperability (via this XNFS specification) and interfaces for application/user portability (via the XSI specifications, in conjunction with the semantic differences defined in the appendices to this document).
This specification is based in part on the X/Open (PC)NFS Specification.
The X/Open (PC)NFS Specification defines the protocols for communication between a PC client running DOS or OS/2 and an X/Open-compliant server.
The XNFS specification defines:
Since many of the protocols used are the same for PC and X/Open-compliant system clients, there is obviously a great deal of overlap between these specifications.
In the event of any inconsistency or disagreement between the two documents, this document is to be treated as authoritative. At some future date, the X/Open (PC)NFS Specification will be revised to include only those elements which are specific to PC clients, such as the pcnfsd protocol, filename and attribute mapping, and the transmission analysis.
The second audience is the developers of X/Open CAE applications.
This group relies upon the semantics of the XSI as defined in the
X/Open System Interfaces and Headers Specification (see reference XSH) and the X/Open Commands and Utilities Specification (see reference XCU) and needs to be aware of any semantic changes which
the use of XNFS may introduce.
These changes are described in
A summary of these changes follows:
- | [ "unsigned" ] "hyper"
- AUTH_DES = 3, AUTH_KERB = 4,
to the auth_flavor definition.
AT&T® is a registered trademark of AT&T in the U.S.A. and other countries.
Diablo® is a registered trademark of Xerox Corporation.
Ethernet® is a registered trademark of Xerox Corporation.
IBM® is a registered trademark of International Business Machines Corporation.
LAN ManagerTM; is a trademark of Microsoft Corporation.
MS-DOS® is a registered trademark of Microsoft Corporation.
NFS® is a registered trademark and Network File SystemTM; is a trademark of Sun Microsystems, Inc.
OS/2® is a registered trademark of International Business Machines Corporation.
PC-NFSTM; is a trademark of Sun Microsystems, Inc..
Postscript® is a registered trademark of Adobe Systems Incorporated.
VAX® is a registered trademark of Digital Equipment Corporation.
VMS® is a registered trademark of Digital Equipment Corporation.
Motif,® OSF/1,® UNIX,® and the "X Device"® are registered trademarks and IT DialToneTM; and The Open GroupTM; are trademarks of The Open Group in the U.S. and other countries.
WebNFSTM; is a trademark of Sun Microsystems, Inc.
- http://www.isi.edu/rfc-editor/ http://ds.internic.net/ds/rfc-index.html/
RFCs can be obtained via FTP from DS.INTERNIC.NET, NIS.NSF.NET, NISC.JVNC.NET, FTP.ISI.EDU, WUARCHIVE.WUSTL.EDU, SRC.DOC.IC.AC.UK, FTP.NCREN.NET, FTP.SESQUI.NET, FTP.NIC.IT, or FTP.IMAG.FR, using the FTP username anonymous and the FTP password guest For further information about Internet Protocols in general, please contact:
Tel: (+1) 213-822-1511
The descriptions which follow are derived from RFC 1011.
All of the preceding material should be interpreted in accordance with the following two documents, which provide an authoritative policy on the way in which the various protocols should be implemented and administered:
In addition, XDR, RPC and NFS are described in the following RFCs:
Andrew D. Birrell and Bruce Jay Nelson, Implementing Remote Procedure Calls, XEROX CSL-83-7, October 1983.
Danny Cohen, On Holy Wars and a Plea for Peace, IEEE Computer, October 1981.
Courier: The Remote Procedure Call Protocol, XEROX Corporation, XSIS 038112, December 1981.
Brian W. Kernighan and Dennis M. Ritchie, The C Programming Language, Bell Laboratories, Murray Hill, New Jersey, 1978.
J. Postel, Transmission Control Protocol - DARPA Internet Program Protocol Specification, RFC 793, Information Sciences Institute, September 1981.
J. Postel, User Datagram Protocol, RFC 768, Information Sciences Institute, August 1980.
Disk Operating System Technical Reference, IBM part no. 6138536.