Object-Based Parallel NFS (pNFS) Operations
RFC 5664

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Internet Engineering Task Force (IETF)                         B. Halevy
Request for Comments: 5664                                      B. Welch
Category: Standards Track                                     J. Zelenka
ISSN: 2070-1721                                                  Panasas
                                                            January 2010

              Object-Based Parallel NFS (pNFS) Operations

Abstract

   Parallel NFS (pNFS) extends Network File System version 4 (NFSv4) to
   allow clients to directly access file data on the storage used by the
   NFSv4 server.  This ability to bypass the server for data access can
   increase both performance and parallelism, but requires additional
   client functionality for data access, some of which is dependent on
   the class of storage used, a.k.a. the Layout Type.  The main pNFS
   operations and data types in NFSv4 Minor version 1 specify a layout-
   type-independent layer; layout-type-specific information is conveyed
   using opaque data structures whose internal structure is further
   defined by the particular layout type specification.  This document
   specifies the NFSv4.1 Object-Based pNFS Layout Type as a companion to
   the main NFSv4 Minor version 1 specification.

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/rfc5664.

Halevy, et al.              Standards Track                     [Page 1]
RFC 5664                      pNFS Objects                  January 2010

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
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   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.

Table of Contents

   1. Introduction ....................................................3
      1.1. Requirements Language ......................................4
   2. XDR Description of the Objects-Based Layout Protocol ............4
      2.1. Code Components Licensing Notice ...........................4
   3. Basic Data Type Definitions .....................................6
      3.1. pnfs_osd_objid4 ............................................6
      3.2. pnfs_osd_version4 ..........................................6
      3.3. pnfs_osd_object_cred4 ......................................7
      3.4. pnfs_osd_raid_algorithm4 ...................................8
   4. Object Storage Device Addressing and Discovery ..................8
      4.1. pnfs_osd_targetid_type4 ...................................10
      4.2. pnfs_osd_deviceaddr4 ......................................10
           4.2.1. SCSI Target Identifier .............................11
           4.2.2. Device Network Address .............................11
   5. Object-Based Layout ............................................12
      5.1. pnfs_osd_data_map4 ........................................13
      5.2. pnfs_osd_layout4 ..........................................14
      5.3. Data Mapping Schemes ......................................14
           5.3.1. Simple Striping ....................................15
           5.3.2. Nested Striping ....................................16
           5.3.3. Mirroring ..........................................17
      5.4. RAID Algorithms ...........................................18
           5.4.1. PNFS_OSD_RAID_0 ....................................18
           5.4.2. PNFS_OSD_RAID_4 ....................................18
           5.4.3. PNFS_OSD_RAID_5 ....................................18
           5.4.4. PNFS_OSD_RAID_PQ ...................................19
           5.4.5. RAID Usage and Implementation Notes ................19
   6. Object-Based Layout Update .....................................20
      6.1. pnfs_osd_deltaspaceused4 ..................................20
      6.2. pnfs_osd_layoutupdate4 ....................................21
   7. Recovering from Client I/O Errors ..............................21