"However, one domain not traditionally well served by NFS is high-performance computing (HPC), where data files are very large, sometimes huge, and the number of NFS clients can reach into the thousands. (Think of a compute cluster or grid composed of thousands of commodity computing nodes.) Here, NFS is a liability, because the limits of the NFS server—be it bandwidth, storage capacity, or processor speed—throttle the overall performance of the computation. NFS is a bottleneck.
"Or, at least it was.
"The next revision of NFS, version 4.1, includes an extension called Parallel NFS (pNFS) that combines the advantages of stock NFS with the massive transfer rates proffered by parallelized input and output (I/O). Using pNFS, file systems are shared from server to clients as before, but data does not pass through the NFS server. Instead, client systems and the data storage system connect directly, providing numerous parallelized, high-speed data paths for massive data transfers. After a bit of initialization and handshaking, the pNFS server is left "out of the loop," and it no longer hinders transfer rates."
