“NFS version 4, published in April 2003, introduced stateful
client-server interaction and ‘file delegation,’ which allows a
client to gain temporary exclusive access to a file on a server.
NFSv4 brings security improvements such as RPCSEC_GSS, the ability
to send multiple operations to the server at once, new file
attributes, replication, client side caching, and improved file
locking. Although there are a number of improvements in NFSv4 over
previous versions, this article investigates just one of
them–performance.“One issue with migrating to NFSv4 is that all of the
filesystems you export have to be located under a single top-level
exported directory…”