Re: lack of raw disk devices

Adam D. Bradley (artdodge@cs.bu.edu)
Tue, 6 Jan 1998 14:57:23 -0500 (EST)


> The direct device access (buffered or not) applications have
> one benefit which allows them to beat filesystem based file
> access in speed. Namely the usual indirected-blockpointer
> scheme at EXT2 becomes more and more slow when the file grows.
>
> Therefore we can't seriously suggest obsoleting raw-device
> access as long as we can't provide efficient means for
> continguous file allocation and access with minimum meta-data
> slowdown. Hmm.. I will think about this...

You may want to try to dig up an old POSIX.4 draft, and read the stuff
about "real-time files"... they got cut from the standard, but
provided this kind of functionality. (Gallmeister talks about them a
little in his book on POSIX.4)

Adam

--
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