*BSD News Article 62428


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From: j@uriah.heep.sax.de (J Wunsch)
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Re: Poor performance with INN and FreeBSD.
Date: 26 Feb 1996 01:46:00 +0100
Organization: Private FreeBSD site, Dresden.
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Distribution: inet
Message-ID: <4gqvs8$7u@uriah.heep.sax.de>
References: <311F8C62.4BC4@pluto.njcc.com> <4gf2p0$209@fozzie.sun3.iaf.nl> <4gij7n$pmm@uriah.heep.sax.de> <4go23v$8hp@fozzie.sun3.iaf.nl>
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Geert Bosch <geert@fozzie.sun3.iaf.nl> wrote:
>J Wunsch (j@uriah.heep.sax.de) wrote:
>: BSD uses a filesystem with linear directories, but the directory
>: contains just an pointer to the i-node information (unlike e.g. OS/2,
>: where the directory contains the equivalent of an i-node itself).

>But if you have to look for a certain filename you'd still have to
>do a lineair search which is what is causing the large overhead when
>accessing news articles in a large directory. 

``large'' overhead is certainly an overstatement, unless you're going
to put your news server on a 386sx/16.

Searching is a mostly computing-intensive operation once you've got
the disk blocks in memory.  The file system buffer cache ensures the
latter.  CPU cycles are rather cheap these days, compared to disk
transfers.

>Since I don't know much about filesystems, my proposal might very well
>be completely stupid or not applicable to FreeBSD. Since I'm not afraid
>to learn, please tell me why.

I doubt anybody will be bothered enough to rewrite a file system from
scratch just for news servers. :)  (Almost everything else doesn't
have more than a few hundred entries per directory.)
-- 
cheers, J"org

joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)