Extensions for Weak Cache Consistency in NFSv4.2's Flexible File Layout
RFC 9766, “Extensions for Weak Cache Consistency in NFSv4.2's Flexible File Layout”, is a Proposed Standard document published in April 2025 by T. Haynes, T. Myklebust. The canonical text is published by the RFC Editor.
Abstract
This document specifies extensions to NFSv4.2 for improving Weak Cache Consistency (WCC). These extensions introduce mechanisms that ensure partial writes performed under a Parallel NFS (pNFS) layout remain coherent and correctly tracked. The solution addresses concurrency and data integrity concerns that may arise when multiple clients write to the same file through separate data servers. By defining additional interactions among clients, metadata servers, and data servers, this specification enhances the reliability of NFSv4 in parallel-access environments and ensures consistency across diverse deployment scenarios.
What “Proposed Standard” means
An entry-level standards-track specification: stable, peer-reviewed and a solid basis for implementation, though it may still evolve before becoming an Internet Standard.
The canonical text of RFC 9766 is hosted at rfc-editor.org. Available in HTML,TXT,PDF,XML.
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