Problem Statement: Abstract

Garth Gibson, Panasas Inc. & CMU and Peter Corbett, Network Appliance, Inc., July 2004

This draft considers the problem of limited bandwidth to NFS servers. The bandwidth limitation exists because an NFS server has limited network, CPU, memory and disk I/O resources. Yet, access to any one file system through the NFSv4 protocol requires that a single server be accessed. While NFSv4 allows file system migration, it does not provide a mechanism that supports multiple servers simultaneously exporting a single writable file system.

This problem has become aggravated in recent years with the advent of very cheap and easily expanded clusters of application servers that are also NFS clients. The aggregate bandwidth demands of such clustered clients, typically working on a shared data set preferentially stored in a single file system, can increase much more quickly than the bandwidth of any server. The proposed solution is to provide for the parallelization of file services, by enhancing NFSv4 in a minor version.


  • pNFS Problem Statement. Garth Gibson, Peter Corbett. Internet Draft, July, 2004.
    text file [30K]
    archived copy

  • Parallel NFS Requirements and Design Considerations. G. Gibson, B. Welch, G. Goodson, P. Corbett. Internet Draft, October 18, 2004.
    text file [25K]
    archived copy

  • pNFS Operations Summary. Brent Welch, Benny Halevy, David Black, Andy Adamson, Dave Noveck. Internet Draft, October 18, 2004.
    text file [50K]
    archived copy

  • Ongoing development of pNFS takes place in the NFSv4 working group of the IETF

Code Download: P-Reg

P-Reg is a performance regression suite and debugging tool for parallel NFS (pNFS). The tool allows the user to run performance tests on pNFS system and simultaneously collect debug information. It provides the user with summarized outputs of the tests and debug information to compare 2 or more diffrent runs and also debug performance issues. P-reg runs on Linux Operating system and is tested using the pNFS over PVFS2 implementation available at CITI.

It is necessary to download 3 files to compile the tool.

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We thank the members and companies of the PDL Consortium: Amazon, Google, Hitachi Ltd., Honda, Intel Corporation, IBM, Meta, Microsoft Research, Oracle Corporation, Pure Storage, Salesforce, Samsung Semiconductor Inc., Two Sigma, and Western Digital for their interest, insights, feedback, and support.