Nightmare File System

Pejorative hackerism for Sun's Network File System (NFS).In any nontrivial network of Suns where there is a lot of NFScross-mounting, when one Sun goes down, the others oftenfreeze up. Some machine tries to access the down one, and(getting no response) repeats indefinitely. This causes it toappear dead to some messages (what is actually happening isthat it is locked up in what should have been a briefexcursion to a higher spl level). Then another machinetries to reach either the down machine or the pseudo-downmachine, and itself becomes pseudo-down. The first machine todiscover the down one is now trying both to access the downone and to respond to the pseudo-down one, so it is evenharder to reach. This situation snowballs very quickly, andsoon the entire network of machines is frozen - worst ofall, the user can't even abort the file access that startedthe problem!

Many of NFS's problems are excused by partisans as being aninevitable result of its statelessness, which is held to bea great feature (critics, of course, call it a greatmisfeature). ITS partisans are apt to cite this as proofof Unix's alleged bogosity; ITS had a working NFS-likeshared file system with none of these problems in the early1970s. See also broadcast storm.

单词	nightmare file system
释义	Nightmare File System Nightmare File System Pejorative hackerism for Sun's Network File System (NFS).In any nontrivial network of Suns where there is a lot of NFScross-mounting, when one Sun goes down, the others oftenfreeze up. Some machine tries to access the down one, and(getting no response) repeats indefinitely. This causes it toappear dead to some messages (what is actually happening isthat it is locked up in what should have been a briefexcursion to a higher spl level). Then another machinetries to reach either the down machine or the pseudo-downmachine, and itself becomes pseudo-down. The first machine todiscover the down one is now trying both to access the downone and to respond to the pseudo-down one, so it is evenharder to reach. This situation snowballs very quickly, andsoon the entire network of machines is frozen - worst ofall, the user can't even abort the file access that startedthe problem! Many of NFS's problems are excused by partisans as being aninevitable result of its statelessness, which is held to bea great feature (critics, of course, call it a greatmisfeature). ITS partisans are apt to cite this as proofof Unix's alleged bogosity; ITS had a working NFS-likeshared file system with none of these problems in the early1970s. See also broadcast storm.
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