From: Mike Fedyk <mfedyk@matchmail.com>
To: Erik Tews <erik.tews@gmx.net>
Cc: linux-kernel@vger.kernel.org
Subject: Re: linux readahead setting?
Date: Wed, 14 Nov 2001 12:26:20 -0800 [thread overview]
Message-ID: <20011114122620.A10172@mikef-linux.matchmail.com> (raw)
In-Reply-To: <Pine.LNX.4.30.0111131619230.1290-100000@mustard.heime.net> <Pine.LNX.4.33L.0111131355030.20809-100000@duckman.distro.conectiva> <20011113181650.A30354@no-maam.dyndns.org> <20011113220139.B30354@no-maam.dyndns.org>
In-Reply-To: <20011113220139.B30354@no-maam.dyndns.org>
On Tue, Nov 13, 2001 at 10:01:39PM +0100, Erik Tews wrote:
> Thanks, for all the answers via pm, but I would like to explain a litte
> bit more what I am looking for. I got this filesystem on lvm, and I want
> my harddisk if there a several processes accessing the disk-image to go
> to the position of process one, read 256k of data, go to the position of
> process two, read 256k of data, go again to the position of the nex
> process, read 256k of data and so one to minimize movement of the
> harddisk-readhead.
>
At which level do you want the read ahead?
If you read ahead at the block level, you may not get data for the file you
want because of fragmentation. This is especially true with long running
Reiser file systems.
If you read ahead at the FS level, you could get even more seeking because
of fragmentation.
Also, you need enough memory to let the kernel hold the read ahead data long
enough to be used.
Mike
next prev parent reply other threads:[~2001-11-14 20:26 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-11-13 15:21 linux readahead setting? Roy Sigurd Karlsbakk
2001-11-13 15:55 ` Rik van Riel
2001-11-13 17:16 ` Erik Tews
2001-11-13 21:01 ` Erik Tews
2001-11-14 20:26 ` Mike Fedyk [this message]
2001-11-14 20:41 ` Erik Tews
2001-11-14 20:47 ` Mike Fedyk
2001-11-14 0:37 ` [PATCH] " Roger Larsson
2001-11-14 10:33 ` Guest section DW
2001-11-14 11:04 ` Roy Sigurd Karlsbakk
2001-11-14 18:31 ` Andre Hedrick
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20011114122620.A10172@mikef-linux.matchmail.com \
--to=mfedyk@matchmail.com \
--cc=erik.tews@gmx.net \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox