Poor Read Performance of 'stdio' Data From NFS 4 in RHEL 6

Solution In Progress - Updated -


  • Using a custom application that reads stdio data from an NFS 4 mountpoints results in unacceptably slow throughput
  • Application gets poor performance in NFS with stdio
  • Default buffer size from stat on an NFS 4 mount has poor read performance using stdio
  • Poor read performance of stdio data from NFS in Red Hat Enterprise Linux 6. Application that uses stdio to read data sets default buffer sizes according to the block size of the underlying filesystem as returned by stat.
    • See Diagnostic Steps for code examples to reproduce the issue


  • Red Hat Enterprise Linux (RHEL) 6.4
  • NFSv4 Mounted Filesystem
    • Filesystem has a minimum rsize 1MB
  • An application which reads data via stdio
    • An input file on an NFS 4 filesystem

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