All of lore.kernel.org
 help / color / mirror / Atom feed
From: Willy Tarreau <w@1wt.eu>
To: Tim Schmielau <tim@physik3.uni-rostock.de>
Cc: "Ismail Dönmez" <ismail@pardus.org.tr>, linux-kernel@vger.kernel.org
Subject: Re: Abysmal disk performance, how to debug?
Date: Sat, 20 Jan 2007 21:31:41 +0100	[thread overview]
Message-ID: <20070120203140.GE25307@1wt.eu> (raw)
In-Reply-To: <Pine.LNX.4.63.0701202124180.23674@gockel.physik3.uni-rostock.de>

On Sat, Jan 20, 2007 at 09:28:57PM +0100, Tim Schmielau wrote:
> On Sat, 20 Jan 2007, Willy Tarreau wrote:
> 
> > Anyway, in your situation with a very small buffer, this should not 
> > change by more than half a second or so.
> 
> Well, his buffer is not small. He has half a GB of RAM, so when 
> writing 1 GB the buffer would roughly double the dd speed, exactly as he 
> has shown us.

yes, but he sees the opposite : when using half of the memory for the
buffer, he has low speed. When shorting cache size to 2% only, he doubles
his speed.

> Anyways, instead of always just posting similar answers to yours, I'll 
> have dinner now. :-)

:-)
Willy


  reply	other threads:[~2007-01-20 20:32 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-01-20 17:20 Abysmal disk performance, how to debug? Ismail Dönmez
2007-01-20 17:45 ` Willy Tarreau
2007-01-20 17:52   ` Ismail Dönmez
2007-01-20 18:03     ` Willy Tarreau
2007-01-20 18:06       ` Ismail Dönmez
2007-01-20 19:44       ` Sunil Naidu
2007-01-20 19:56         ` Stephen Clark
2007-01-20 20:09           ` Willy Tarreau
2007-01-21  3:41             ` Stephen Clark
2007-01-21  4:06               ` Gene Heskett
2007-01-27 19:43             ` Bill Davidsen
2007-02-03 17:22               ` Elladan
2007-01-20 20:05         ` Willy Tarreau
2007-01-20 20:11           ` Ismail Dönmez
2007-01-20 20:10     ` Tim Schmielau
2007-01-20 20:16       ` Ismail Dönmez
2007-01-20 20:19         ` Willy Tarreau
2007-01-20 20:28           ` Tim Schmielau
2007-01-20 20:31             ` Willy Tarreau [this message]
2007-01-20 20:21         ` Tim Schmielau
2007-01-20 20:28       ` Willy Tarreau
2007-01-20 20:39         ` Tim Schmielau
2007-01-20 21:24           ` Willy Tarreau
2007-01-20 21:41             ` Tim Schmielau
2007-01-20 21:12       ` Sunil Naidu
2007-01-20 22:00         ` Tim Schmielau
2007-01-20 23:47           ` Sunil Naidu

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=20070120203140.GE25307@1wt.eu \
    --to=w@1wt.eu \
    --cc=ismail@pardus.org.tr \
    --cc=linux-kernel@vger.kernel.org \
    --cc=tim@physik3.uni-rostock.de \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.