Network File System (NFS) is a distributed file system protocol originally developed by Sun Microsystems (Sun) in 1984, allowing a user on a client computer to access files over a computer network much like local storage is accessed. ^[1]

NFS (client) knows to update local cache by comparing inode modification time, learn a bit more Multi-grain Timestamps

adds LOCALIO protocol extension support, it can detect if host/client are on the same system and if it is the case, it will bypass the use of XDR and RPC (Which is a lot like not packing up something in a box and instead giving the article without it.) this can yield up to 10X improvement for reads. ^[2]

The NFS server now supports NFS4.2+ attribute delegation: "An attribute delegation permits an NFS client to manage a file's mtime, rather than flushing dirty data to the NFS server so that the file's mtime reflects the last write, which is considerably slower."^[3]TLDR Better handling of Modification Time now added to the server, that was already added to the client in 6.11.

The NFS "localio" functionality has been enhanced so that clients can perform direct I/O in cases where the client and server are on the same host.^[3]