Editing Network File System (section)

== Protocol development ==
During the development of the ONC protocol (called [[SunRPC]] at the time), only Apollo's [[Network Computing System]] (NCS) offered comparable functionality. Two competing groups developed over fundamental differences in the two remote procedure call systems. Arguments focused on the  method for data-encoding — ONC's [[External Data Representation]] (XDR) always rendered integers in [[big-endian]] order, even if both peers of the connection had [[little-endian]] machine-architectures, whereas NCS's method attempted to avoid byte-swap whenever two peers shared a common [[endianness]] in their machine-architectures. An industry-group called the [[Network Computing Forum]] formed (March 1987) in an (ultimately unsuccessful) attempt to reconcile the two network-computing environments.

In 1987, Sun and AT&T announced they would jointly develop AT&T's UNIX System V Release 4.<ref>{{cite news
 | author1 = Carole Patton
 | title = AT&T to License Sun Microsystems' SPARC Chip
 | url = https://books.google.com/books?id=_z4EAAAAMBAJ&pg=PA37
 | work = [[InfoWorld]]
 | page = 37
 | date = 1987-10-26
 | access-date = 2019-07-16
}}</ref> This caused many of AT&T's other licensees of UNIX System to become concerned that this would put Sun in an advantaged position, and ultimately led to Digital Equipment, HP, IBM, and others forming the [[Open Software Foundation]] (OSF) in 1988. Ironically, Sun and AT&T had formerly competed over Sun's NFS versus AT&T's [[Remote File System]] (RFS), and the quick adoption of NFS over RFS by Digital Equipment, HP, IBM, and many other computer vendors tipped the majority of users in favor of NFS.
NFS [[interoperability]] was aided by events called "Connectathons" starting in 1986 that allowed vendor-neutral testing of implementations with each other.<ref>{{Cite web |title= What is Connectathon? |website= Original Connectathon.Org web site |url= http://www.connectathon.org/ |archive-url= https://web.archive.org/web/19990128152940/http://www.connectathon.org/#whatis |archive-date= January 28, 1999}}</ref> OSF adopted the [[Distributed Computing Environment]] (DCE) and the [[DCE Distributed File System]] (DFS) over Sun/ONC RPC and NFS. DFS used DCE as the RPC, and DFS derived from the [[Andrew File System]] (AFS); DCE itself derived from a suite of technologies, including Apollo's NCS and [[Kerberos (protocol)|Kerberos]].{{citation needed|date=January 2014}}

=== 1990s ===
Sun Microsystems and the [[Internet Society]] (ISOC) reached an agreement to cede "change control" of ONC RPC so that the ISOC's engineering-standards body, the [[Internet Engineering Task Force]] (IETF), could publish standards documents (RFCs) related to ONC RPC protocols and could extend ONC RPC. OSF attempted to make DCE RPC an IETF standard, but ultimately proved unwilling to give up change control. Later, the IETF chose to extend ONC RPC by adding a new authentication flavor based on [[Generic Security Services Application Program Interface]] (GSSAPI), [[RPCSEC GSS]], to meet IETF requirements that protocol standards have adequate security.

Later, Sun and ISOC reached a similar agreement to give ISOC change control over NFS, although writing the contract carefully to exclude NFS version 2 and version 3. Instead, ISOC gained the right to add new versions to the NFS protocol, which resulted in IETF specifying NFS version 4 in 2003.

=== {{anchor|PNFS}}2000s ===
By the 21st century, neither DFS nor AFS had achieved any major commercial success as compared to SMB or NFS.  IBM, which had formerly acquired the primary commercial vendor of DFS and AFS, [[Transarc]], donated most of the AFS source code to the [[free software community]] in 2000. The [[OpenAFS]] project lives on. In early 2005, IBM announced end of sales for AFS and DFS.

In January, 2010, [[Panasas]] proposed an NFSv4.1 based on their ''Parallel NFS'' (pNFS) technology claiming to improve data-access parallelism<ref>{{Cite web |title= pNFS |publisher= [[Panasas]] |url= http://www.pnfs.com |access-date= August 4, 2013 }}</ref> capability. The NFSv4.1 protocol defines a method of separating the [[metadata#File system metadata|filesystem meta-data]] from file data location; it goes beyond the simple name/data separation by striping the data amongst a set of data servers. This differs from the traditional NFS server which holds the names of files and their data under the single umbrella of the server. Some products are multi-node NFS servers, but the participation of the client in separation of meta-data and data is limited.

The NFSv4.1 pNFS server is a set of server resources or components; these are assumed to be controlled by the meta-data server.

The pNFS client still accesses one meta-data server for traversal or interaction with the namespace; when the client moves data to and from the server it may directly interact with the set of data servers belonging to the pNFS server collection. The NFSv4.1 client can be enabled to be a direct participant in the exact location of file data and to avoid solitary interaction with one NFS server when moving data.

In addition to pNFS, NFSv4.1 provides:

* Sessions
* Directory Delegation and Notifications
* Multi-server Namespace
* [[access control list]]s and [[discretionary access control]]
* Retention Attributions
* SECINFO_NO_NAME