1. nightmare file system
Pejorative hackerism for Sun's Network File System (NFS). In any
nontrivial network of Suns where there is a lot of NFS cross-mounting, when
one Sun goes down, the others often freeze up. Some machine tries to
access the down one, and (getting no response) repeats indefinitely. This
causes it to appear dead to some messages (what is actually happening is
that it is locked up in what should have been a brief excursion to a higher
spl level). Then another machine tries to reach
either the down machine or the pseudo-down machine, and itself becomes
pseudo-down. The first machine to discover the down one is now trying both
to access the down one and to respond to the pseudo-down one, so it is even
harder to reach. This situation snowballs very quickly, and soon the
entire network of machines is frozen — worst of all, the user can't
even abort the file access that started the problem! Many of NFS's
problems are excused by partisans as being an inevitable result of its
statelessness, which is held to be a great feature (critics, of course,
call it a great misfeature). (ITS partisans are apt
to cite this as proof of Unix's alleged bogosity; ITS had a working
NFS-like shared file system with none of these problems in the early
1970s.) See also broadcast storm.
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Definitions of nightmare file system
