Date: Mon, 5 Feb 1996 08:16:27 +0200 (SAT) From: Robert Nordier <rnordier@iafrica.com> To: hackers@freebsd.org Subject: Re: FAT filesystem performance Message-ID: <199602050616.IAA03554@eac.iafrica.com> In-Reply-To: <199602050350.IAA24118@hq.icb.chel.su> from "Serge A. Babkin" at Feb 5, 96 08:50:19 am
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, 5 Jan 1996, Serge A. Babkin wrote:
> > The FAT-caching in the MACH implementation (you *could* just port the
> > MACH code...) takes a significant amount of memory, IMO.
>
> Hmm... FAT can contain at most 64K of entries, each 2 bytes long, so
> the needed amount of memory (if you cache raw FAT and don't try to make
> any ``cooked'' version) must be at most 128Kbytes long. IMHO the raw FAT
> is enough convenient ant takes not very much of memory.
Agreed.
This is what the original author of the MS-DOS filesystem had to say on
the subject of caching:
The new MS-DOS [ie. DOS 2.0] does not keep the file
allocation tables in memory at all times. Instead the
tables share the use of sector buffers.... This change
in the DOS goes completely against my original design
principles.... Now we're back to doing disk reads just
to find out where the data is.
-- Tim Paterson, Byte, June 1983.
--
Robert Nordier
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199602050616.IAA03554>