From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966179AbXDGRVN (ORCPT ); Sat, 7 Apr 2007 13:21:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S966154AbXDGRVN (ORCPT ); Sat, 7 Apr 2007 13:21:13 -0400 Received: from h80ad275a.async.vt.edu ([128.173.39.90]:50108 "EHLO h80ad275a.async.vt.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966143AbXDGRVL (ORCPT ); Sat, 7 Apr 2007 13:21:11 -0400 X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.2 To: Krzysztof Halasa Cc: johnrobertbanks@fastmail.fm, Jan Harkes , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: Reiser4. BEST FILESYSTEM EVER. In-Reply-To: Your message of "Sat, 07 Apr 2007 16:11:46 +0200." From: Valdis.Kletnieks@vt.edu References: <46157B5B.5000602@gmail.com> <1175817921.18400.1183285196@webmail.messagingengine.com> <461592FB.5060507@zytor.com> <1175819681.20754.1183287946@webmail.messagingengine.com> <461596DE.2020802@zytor.com> <1175823288.25662.1183293506@webmail.messagingengine.com> <4615C780.5040407@zytor.com> <1175833931.8916.1183307802@webmail.messagingengine.com> <20070406152119.GC4228@delft.aura.cs.cmu.edu> <1175914056.9653.1183426876@webmail.messagingengine.com> <20070407033049.GI4228@delft.aura.cs.cmu.edu> <1175925525.21154.1183436614@webmail.messagingengine.com> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1175966465_4736P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Sat, 07 Apr 2007 13:21:05 -0400 Message-ID: <14133.1175966465@turing-police.cc.vt.edu> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --==_Exmh_1175966465_4736P Content-Type: text/plain; charset=us-ascii On Sat, 07 Apr 2007 16:11:46 +0200, Krzysztof Halasa said: > > Gzip - 3 files (zeros only, raw DV data from video camera, x86_64 > kernel rpm file), 10 MB of data (10*1024*1024), > $ l -Ggh zeros dv bin > -rw-r--r-- 1 10M Apr 7 15:30 bin > -rw-r--r-- 1 10M Apr 7 15:31 dv > -rw-r--r-- 1 10M Apr 7 15:31 zeros > $ l -Ggh zeros.gz dv.gz bin.gz > -rw-r--r-- 1 10K Apr 7 15:31 zeros.gz > -rw-r--r-- 1 9.1M Apr 7 15:31 dv.gz > -rw-r--r-- 1 9.3M Apr 7 15:30 bin.gz > > ... and though the numbers may still sound impressive, space savings > are less than 10%. I am quite sure that the kernel RPM file is *already* compressed, at least somewhat. Otherwise, it's hard to explain this: -rw-r--r-- 1 529 263 17835757 Apr 5 00:19 kernel-2.6.20-1.3045.fc7.x86_64.rpm % du -s /lib/modules/2.6.20-1.3038.fc7/ 76436 /lib/modules/2.6.20-1.3038.fc7/ and it can't all be slack space at ends of files: % find /lib/modules/2.6.20-1.3038.fc7/ -type f | wc -l 1482 Even on a 4K filesystem, the *max* wasted slack would be about 4M. And what do you know - if you tar.gz that /lib/modules: % tar czf /tmp/kern.tar.gz /lib/modules/2.6.20-1.3038.fc7/ tar: Removing leading `/' from member names % ls -l /tmp/kern.tar.gz -rw-r--r-- 1 valdis valdis 15506359 2007-04-07 13:19 /tmp/kern.tar.gz The *compressed* tar is about 15M (remember the .rpm contained a 2M vmlinuz as well - that;s compressed too). So we're right up to the 17M of the .rpm, which indicates that the RPM is compressed at a factor close to tar.gz. I'd not be surprised to find out that your digital-video also contains at least some light compression - if it's mpeg or similar, that's already had some *heavy* compression done to it.... --==_Exmh_1175966465_4736P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (GNU/Linux) Comment: Exmh version 2.5 07/13/2001 iD8DBQFGF9MBcC3lWbTT17ARAnKtAJ9XGPthGNaIjLVPapOXX3gCYTYb1gCgzcGa TyO+vN3sMuy0cWvZ/M39ldw= =ux2q -----END PGP SIGNATURE----- --==_Exmh_1175966465_4736P--