Hammerspace The Flexible File Version 2 pNFS layout type defines a chunk-oriented data-server protocol in which every write is a full-chunk payload. For workloads that make small edits to files protected by an XOR- based erasure encoding, this forces client-side stripe fetch, re- encode, and transmit on every edit, with wire amplification of three to four orders of magnitude per byte edited. This document defines an optional extension, CHUNK_XOR_DELTA, that lets a client transmit a per-projection XOR delta directly to each data server holding a projection of the affected stripe; the data server applies the delta locally. The extension is restricted to XOR-linear systematic encodings and XOR-affine checksums, using the existing chunk state machine with no new commit protocol.