From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755604AbYHVRUc (ORCPT ); Fri, 22 Aug 2008 13:20:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752585AbYHVRUX (ORCPT ); Fri, 22 Aug 2008 13:20:23 -0400 Received: from lazybastard.de ([212.112.238.170]:42580 "EHLO longford.logfs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752882AbYHVRUX (ORCPT ); Fri, 22 Aug 2008 13:20:23 -0400 Date: Fri, 22 Aug 2008 19:19:59 +0200 From: =?utf-8?B?SsO2cm4=?= Engel To: Phillip Lougher Cc: Arnd Bergmann , jaredeh@gmail.com, Linux-kernel@vger.kernel.org, linux-embedded@vger.kernel.org, linux-mtd , tim.bird@am.sony.com, cotte@de.ibm.com, nickpiggin@yahoo.com.au Subject: Re: [PATCH 04/10] AXFS: axfs_inode.c Message-ID: <20080822171959.GA30977@logfs.org> References: <48AD00F0.5030403@gmail.com> <200808211417.14425.arnd@arndb.de> <48AE22F5.3000309@lougher.demon.co.uk> <200808221200.26052.arnd@arndb.de> <48AEF2A3.7020905@lougher.demon.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <48AEF2A3.7020905@lougher.demon.co.uk> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 22 August 2008 18:08:51 +0100, Phillip Lougher wrote: > > Squashfs stores significantly more metadata than cramfs. Remember > cramfs has no support for filesystems > ~ 16Mbytes, no inode timestamps, > truncates uid/gids, no hard-links, no nlink counts, no hashed > directories, no unique inode numbers. If Squashfs didn't compress the > metadata it would be significantly larger than cramfs. Elsewhere in this maze of threads Arnd claimed to have tested the benefits of metadata compression - and it making little impact. My guess is that it would make a large impact if metadata would be a significant part of the filesystem image. Usually metadata is close enough to 0% to be mistaken for statistical noise. So compressing it makes a significant impact on an insignificant amount of data. Jörn -- One of my most productive days was throwing away 1000 lines of code. -- Ken Thompson.