Parallel NFS (pNFS) Flexible File Layout
draft-ietf-nfsv4-flex-files-16
| The information below is for an old version of the document | |||
|---|---|---|---|
| Document | Type | Active Internet-Draft (nfsv4 WG) | |
| Last updated | 2018-01-25 | ||
| Stream | IETF | ||
| Intended RFC status | Proposed Standard | ||
| Formats | pdf htmlized bibtex | ||
| Reviews | |||
| Stream | WG state | Submitted to IESG for Publication | |
| Document shepherd | Spencer Shepler | ||
| Shepherd write-up | Show (last changed 2017-10-25) | ||
| IESG | IESG state | IESG Evaluation::AD Followup | |
| Consensus Boilerplate | Yes | ||
| Telechat date |
Needs a YES. Needs 3 more YES or NO OBJECTION positions to pass. |
||
| Responsible AD | Spencer Dawkins | ||
| Send notices to | Spencer Shepler <spencer.shepler@gmail.com> | ||
| IANA | IANA review state | Version Changed - Review Needed | |
NFSv4 B. Halevy
Internet-Draft
Intended status: Standards Track T. Haynes
Expires: July 29, 2018 Primary Data
January 25, 2018
Parallel NFS (pNFS) Flexible File Layout
draft-ietf-nfsv4-flex-files-16.txt
Abstract
The Parallel Network File System (pNFS) allows a separation between
the metadata (onto a metadata server) and data (onto a storage
device) for a file. The flexible file layout type is defined in this
document as an extension to pNFS which allows the use of storage
devices in a fashion such that they require only a quite limited
degree of interaction with the metadata server, using already
existing protocols. Client-side mirroring is also added to provide
replication of files.
Status of This Memo
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provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on July 29, 2018.
Copyright Notice
Copyright (c) 2018 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
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publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
Halevy & Haynes Expires July 29, 2018 [Page 1]
Internet-Draft Flex File Layout January 2018
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Definitions . . . . . . . . . . . . . . . . . . . . . . . 4
1.2. Requirements Language . . . . . . . . . . . . . . . . . . 6
2. Coupling of Storage Devices . . . . . . . . . . . . . . . . . 6
2.1. LAYOUTCOMMIT . . . . . . . . . . . . . . . . . . . . . . 7
2.2. Fencing Clients from the Storage Device . . . . . . . . . 7
2.2.1. Implementation Notes for Synthetic uids/gids . . . . 8
2.2.2. Example of using Synthetic uids/gids . . . . . . . . 9
2.3. State and Locking Models . . . . . . . . . . . . . . . . 10
2.3.1. Loosely Coupled Locking Model . . . . . . . . . . . . 10
2.3.2. Tightly Coupled Locking Model . . . . . . . . . . . . 12
3. XDR Description of the Flexible File Layout Type . . . . . . 13
3.1. Code Components Licensing Notice . . . . . . . . . . . . 14
4. Device Addressing and Discovery . . . . . . . . . . . . . . . 15
4.1. ff_device_addr4 . . . . . . . . . . . . . . . . . . . . . 15
4.2. Storage Device Multipathing . . . . . . . . . . . . . . . 17
5. Flexible File Layout Type . . . . . . . . . . . . . . . . . . 18
5.1. ff_layout4 . . . . . . . . . . . . . . . . . . . . . . . 19
5.1.1. Error Codes from LAYOUTGET . . . . . . . . . . . . . 22
5.1.2. Client Interactions with FF_FLAGS_NO_IO_THRU_MDS . . 23
5.2. LAYOUTCOMMIT . . . . . . . . . . . . . . . . . . . . . . 23
5.3. Interactions Between Devices and Layouts . . . . . . . . 23
5.4. Handling Version Errors . . . . . . . . . . . . . . . . . 23
6. Striping via Sparse Mapping . . . . . . . . . . . . . . . . . 24
7. Recovering from Client I/O Errors . . . . . . . . . . . . . . 24
8. Mirroring . . . . . . . . . . . . . . . . . . . . . . . . . . 25
8.1. Selecting a Mirror . . . . . . . . . . . . . . . . . . . 26
8.2. Writing to Mirrors . . . . . . . . . . . . . . . . . . . 26
8.2.1. Single Storage Device Updates Mirrors . . . . . . . . 26
8.2.2. Client Updates All Mirrors . . . . . . . . . . . . . 26
8.2.3. Handling Write Errors . . . . . . . . . . . . . . . . 27
8.2.4. Handling Write COMMITs . . . . . . . . . . . . . . . 27
8.3. Metadata Server Resilvering of the File . . . . . . . . . 28
9. Flexible Files Layout Type Return . . . . . . . . . . . . . . 28
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