"When you're trying to share files and perform I/O-intensive
operations across 100+ nodes of a Beowulf cluster, the old model of
a central NFS file server handling every client request begins to
break horribly. What many cluster admins do instead is limit NFS to
distributing home directories across the cluster, and using some
form of parallel I/O model for doing 'real work.'
"Of course, cluster administrators and users alike crave the
benefits of an NFS-like system; admins (in many cases) want logins
only to the head node of the cluster, and users want to have all of
their output in one place so they don't have to collect it from the
various local disks of the individual compute nodes..."