From owner-freebsd-current@FreeBSD.ORG  Fri Sep  3 21:35:17 2004
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
Delivered-To: freebsd-current@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id BCDC016A4CE
	for <freebsd-current@freebsd.org>;
	Fri,  3 Sep 2004 21:35:17 +0000 (GMT)
Received: from tomts36-srv.bellnexxia.net (tomts36.bellnexxia.net
	[209.226.175.93])
	by mx1.FreeBSD.org (Postfix) with ESMTP id EFD2943D41
	for <freebsd-current@freebsd.org>;
	Fri,  3 Sep 2004 21:35:16 +0000 (GMT)
	(envelope-from dashevil@sympatico.ca)
Received: from [192.168.2.32] ([65.93.56.160])
	by tomts36-srv.bellnexxia.netESMTP
	<20040903213515.MUKY25796.tomts36-srv.bellnexxia.net@[192.168.2.32]>;
	Fri, 3 Sep 2004 17:35:15 -0400
From: Chris Laverdure <dashevil@sympatico.ca>
To: Giorgos Keramidas <keramida@linux.gr>
In-Reply-To: <20040903211427.GB1199@gothmog.gr>
References: <20040903175434.A812@ganymede.hub.org>
	 <20040903211427.GB1199@gothmog.gr>
Content-Type: text/plain
Message-Id: <1094232909.76688.1.camel@elemental.DashEvil>
Mime-Version: 1.0
X-Mailer: Ximian Evolution 1.4.6 
Date: Fri, 03 Sep 2004 17:35:10 +0000
Content-Transfer-Encoding: 7bit
cc: freebsd-current@freebsd.org
Subject: Re: what is fsck's "slowdown"?
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 03 Sep 2004 21:35:17 -0000

On Fri, 2004-09-03 at 21:14, Giorgos Keramidas wrote:
> On 2004-09-03 18:01, "Marc G. Fournier" <scrappy@hub.org> wrote:
> >
> > load: 0.99  cmd: fsck 67 [running] 15192.26u 142.30s 99% 184284k
> > /dev/da0s1h: phase 4: cyl group 408 of 866 (47%)
> >
> > wouldn't it be possible, on a dual CPU system, to have group 434 and above
> > run on one process, while group 433 and below running on the second, in
> > parallel?  Its not like the drives are being beat up:
> 
> My intuition says that if metadata of the first part of the disk references
> data residing on the second part synchronization and locking would probably
> be a bit difficult; actually very difficult.

My intuition tells me that it would be a much better solution to run
multiple fsck's concurrently. What harm could there be in fscking (num
of processors) partitions at the same time?