RFC 9766: Extensions for Weak Cache Consistency in NFSv4.2's Flexible File Layout

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.