Network File System (NFS) Direct Data Placement
RFC 5667

Internet Engineering Task Force (IETF)                         T. Talpey
Request for Comments: 5667                                  Unaffiliated
Category: Standards Track                                   B. Callaghan
ISSN: 2070-1721                                                    Apple
                                                            January 2010

            Network File System (NFS) Direct Data Placement

Abstract

   This document defines the bindings of the various Network File System
   (NFS) versions to the Remote Direct Memory Access (RDMA) operations
   supported by the RPC/RDMA transport protocol.  It describes the use
   of direct data placement by means of server-initiated RDMA operations
   into client-supplied buffers for implementations of NFS versions 2,
   3, 4, and 4.1 over such an RDMA transport.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc5667.

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   document authors.  All rights reserved.

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Talpey & Callaghan           Standards Track                    [Page 1]
RFC 5667                NFS Direct Data Placement           January 2010

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Table of Contents

   1. Introduction ....................................................2
      1.1. Requirements Language ......................................2
   2. Transfers from NFS Client to NFS Server .........................3
   3. Transfers from NFS Server to NFS Client .........................3
   4. NFS Versions 2 and 3 Mapping ....................................4
   5. NFS Version 4 Mapping ...........................................6
      5.1. NFS Version 4 Callbacks ....................................7
   6. Port Usage Considerations .......................................8
   7. Security Considerations .........................................9
   8. Acknowledgments .................................................9
   9. References ......................................................9
      9.1. Normative References .......................................9
      9.2. Informative References ....................................10

1.  Introduction

   The Remote Direct Memory Access (RDMA) Transport for Remote Procedure
   Call (RPC) [RFC5666] allows an RPC client application to post buffers
   in a Chunk list for specific arguments and results from an RPC call.
   The RDMA transport header conveys this list of client buffer
   addresses to the server where the application can associate them with
   client data and use RDMA operations to transfer the results directly
   to and from the posted buffers on the client.  The client and server
   must agree on a consistent mapping of posted buffers to RPC.  This
   document details the mapping for each version of the NFS protocol
   [RFC1094] [RFC1813] [RFC3530] [RFC5661].

1.1.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",