Network File System (NFS) Direct Data Placement
RFC 5667

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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.

Copyright Notice

   Copyright (c) 2010 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

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

   This document may contain material from IETF Documents or IETF
   Contributions published or made publicly available before November
   10, 2008.  The person(s) controlling the copyright in some of this
   material may not have granted the IETF Trust the right to allow
   modifications of such material outside the IETF Standards Process.
   Without obtaining an adequate license from the person(s) controlling
   the copyright in such materials, this document may not be modified
   outside the IETF Standards Process, and derivative works of it may
   not be created outside the IETF Standards Process, except to format
   it for publication as an RFC or to translate it into languages other
   than English.

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",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

Talpey & Callaghan           Standards Track                    [Page 2]
RFC 5667                NFS Direct Data Placement           January 2010