From owner-freebsd-hackers@FreeBSD.ORG Wed Feb 27 16:50:38 2008 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 34802106566B for ; Wed, 27 Feb 2008 16:50:38 +0000 (UTC) (envelope-from mwm@mired.org) Received: from mired.org (student.mired.org [66.92.153.77]) by mx1.freebsd.org (Postfix) with SMTP id EDCF68FC19 for ; Wed, 27 Feb 2008 16:50:27 +0000 (UTC) (envelope-from mwm@mired.org) Received: (qmail 76780 invoked from network); 27 Feb 2008 16:49:17 -0000 Received: from unknown (HELO mbook-fbsd) (192.168.195.250) by 0 with SMTP; 27 Feb 2008 16:49:17 -0000 Date: Wed, 27 Feb 2008 11:50:46 -0500 From: Mike Meyer To: Joerg Sonnenberger Message-ID: <20080227115046.2e029ff0@mbook-fbsd> In-Reply-To: <20080227125048.GE352@britannica.bec.de> References: <20080225154455.4822e72a@bhuda.mired.org> <47C33384.6040701@dial.pipex.com> <200802252243.m1PMhTeq016201@fire.js.berklix.net> <47C3A228.7090703@freebsd.org> <20080226202853.GA859@britannica.bec.de> <20080226160000.624c5d0f@bhuda.mired.org> <20080227125048.GE352@britannica.bec.de> Organization: Meyer Consulting X-Mailer: Claws Mail 3.0.2 (GTK+ 2.12.5; amd64-portbld-freebsd7.0) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Mailman-Approved-At: Wed, 27 Feb 2008 17:16:44 +0000 Cc: freebsd-hackers@freebsd.org Subject: Re: emulate an end-of-media X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 27 Feb 2008 16:50:38 -0000 On Wed, 27 Feb 2008 13:50:48 +0100 Joerg Sonnenberger wrote: > On Tue, Feb 26, 2008 at 04:00:00PM -0500, Mike Meyer wrote: > > On Tue, 26 Feb 2008 21:28:53 +0100 Joerg Sonnenberger wrote: > > > On Tue, Feb 26, 2008 at 07:44:48PM +0100, Martin Laabs wrote: > > > > I also made a comparison between gzip and bzip2 regarding > > > > the compression ratio on a dump of my home directory (3.2GB) > > > > bzip2 took about 74min to compress, gzip only 11minutes. And > > > > in terms of compression ratio bzip2 was only 3% better than > > > > gzip. > > > That's not a realistic test case. bzip2 normally takes trice the time > > > and compresses 10% better. I can't comment on compress. > > > > Considering we're talking about compression methods to use on dump > > output, that would seem to be the definition of a "realistic test > > case". Telling us what it "normally" does without defining what input > > is considered "normal" doesn't help much. > > Source code in my case and various other documents. The test case above > certainly was not normal. So it sounds like your "normal" is mostly text documents of various kinds. I would expect such data to be a relatively small part of any dump data set, which, as you say, means that such data isn't normal. Given that the use case under discussion is abnormal, any tests using normal data are pretty much irrelevant. http://www.mired.org/consulting.html Independent Network/Unix/Perforce consultant, email for more information.