LATEST UPDATES - CIFS POSIX Extensions presented at the 2007 Ottawa Linux Symposium and at Connectathon. Overview of the most current version will be presented at 2007 Storage Developer Conference in September


Protocol extensions to the Common Internet File System for better POSIX file I/O semantics

Questions to developers 

The CIFS POSIX Extensions are protocol extensions to enable POSIX compliant operating systems to better interoperate with CIFS servers and storage appliances by extending the SNIA CIFS Specification version 1.0.    Popular servers such as Samba, Windows 2000, Windows XP and many others support CIFS by default.  These extensions are already implemented in multiple clients and servers.

30 Second History of the SMB/CIFS Protocol

  • 1984 Initial SMB Specification Published by IBM based on the work of Dr. Bary Feigenbaum and team
  • 1985-1992 SMB Protocol extended by IBM, 3Com, Intel and Microsoft, and becomes the default filesystem protocol for DOS, OS/2 and Windows operating systems among others.
  • 1992 X/Open publishes an updated version of the SMB standard: Protocols for X/Open PC Interworking: SMB Version 2 (CAE 209)
  • 1994-1995 IBM Extends SMB to include support for DCE/Kerberos
  • 1996 With the slow speed of HTTP for certain workloads, two key network filesystem protocols begin to become more "internet friendly." Sun announces WebNFS and Microsoft extends and renames SMB (announcing CIFS - "The Common Internet File System Protocol"). More formal CIFS documentation is written describing the complex SMB/CIFS protocol in detail.
  • 1996-2006 Annual CIFS Deveper Conferences are held to improve interoperability.
  • 1999-2001 SCO and HP add/document optional Unix Extensions to CIFS Protocol, Thursby adds/documents optional Macintosh extensions.
  • 2002 After multiyear effort involving many companies including Microsoft, IBM and NetApp, The Storage Network Industry Association releases the SNIA CIFS Technical Reference (which also includes Unix and Mac protocol extensions for CIFS)
  • 2003 NFSv4 (RFC 3530) released borrowing many ideas from CIFS
  • 2004 Work begins on an improved set of extensions to the CIFS Protocol for better support of POSIX clients.
  • 2006 Samba client and server and Linux client implement CIFS POSIX Extensions
Thanks to SNIA, IBM and the Samba Team
for their assistance and support.