The Single Unix Specification defines POSIX_FADV_NOREUSE as "Specifies that the application expects to access the specified data once and then not reuse it thereafter." Does it mean the data will be needed at most once (possibly not at all), or exactly once? Because in the second case the file system could conceivably try to prefetch the data as an optimization, while in both cases the data could be dropped from the cache after it's accessed. Also, for posix_fadvise in general, does it advise for the current moment in time, or from the current moment until other advisement is issued? I.e. if you use POSIX_FADV_DONTNEED on a region of the file, then read from it, will that part of the file remain in cache (as if POSIX_FADV_DONTNEED was reset), or will it be immediately freed? [Edited by - Catafriggm on January 22, 2006 11:08:16 PM]