Subject: [nfsv4] [Errata Verified] RFC5663 (4139)

From: RFC Errata System <[email-masked]>
Date: Tue, 2 Feb 2016 12:30:35 -0800 (PST)

The following errata report has been verified for RFC5663,
"Parallel NFS (pNFS) Block/Volume Layout". 

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You may review the report below and at:
http://www.rfc-editor.org/errata_search.php?rfc=5663&eid=4139

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Status: Verified
Type: Technical

Reported by: Christoph Hellwig <[email-masked]>
Date Reported: 2014-10-23
Verified by: Martin Stiemerling (IESG)

Section: 2.7

Original Text
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<section doesn't exist yet>

Corrected Text
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2.7.  Volatile write caches

   Many storage devices implement volatile write caches that require an
   explicit flush to persist the data from write write operations to
   stable storage.  When a volatile write cache is used the pNFS server
   must ensure the volatile write cache has been committed to stable
   storage before the LAYOUTCOMMIT operation returns.  An example for
   this behavior are SCSI devices with the WCE (Writeback Cache Enable)
   bit set to 1 in the caching mode page (mode page 0x8),
   which require a "SYNCRONIZE CACHE (10)" or "SYNCRONIZE CACHE (16)"
   operation to write back the storage device cache.

Notes
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RFC5663 currently doesn't acknowledge the existence of volatile write caches, but they are common in consumer or SMB storage systems.  Add a section that requires the server to take care of them.

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RFC5663 (draft-ietf-nfsv4-pnfs-block-12)
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Title               : Parallel NFS (pNFS) Block/Volume Layout
Publication Date    : January 2010
Author(s)           : D. Black, S. Fridella, J. Glasgow
Category            : PROPOSED STANDARD
Source              : Network File System Version 4
Area                : Transport
Stream              : IETF
Verifying Party     : IESG