Hammerspace Hammerspace The Parallel Network File System (pNFS) allows for a file's metadata (MDS) and data (DS) to be on different servers. When the metadata server is restarted, the client can still modify the data file component. During the recovery phase of startup, the metadata server and the data servers work together to recover state (which files are open, last modification time, size, etc). A problem with servers which do client side mirroring there is no means by which the client can report errors to the metadata server. As such, the metadata server has to assume that file needs resilvering. This document presents a refinement to RFC8435 to allow the client to update the metadata