From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263313AbTJOOdK (ORCPT ); Wed, 15 Oct 2003 10:33:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263315AbTJOOdK (ORCPT ); Wed, 15 Oct 2003 10:33:10 -0400 Received: from thebsh.namesys.com ([212.16.7.65]:4255 "HELO thebsh.namesys.com") by vger.kernel.org with SMTP id S263313AbTJOOdH (ORCPT ); Wed, 15 Oct 2003 10:33:07 -0400 From: Nikita Danilov MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <16269.23199.833564.163986@laputa.namesys.com> Date: Wed, 15 Oct 2003 18:33:03 +0400 To: Erik Mouw Cc: Josh Litherland , linux-kernel@vger.kernel.org Subject: Re: Transparent compression in the FS In-Reply-To: <20031015142738.GG24799@bitwizard.nl> References: <1066163449.4286.4.camel@Borogove> <20031015133305.GF24799@bitwizard.nl> <16269.20654.201680.390284@laputa.namesys.com> <20031015142738.GG24799@bitwizard.nl> X-Mailer: ed | telnet under Fuzzball OS, emulated on Emacs 21.5 (beta14) "cassava" XEmacs Lucid Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Erik Mouw writes: > On Wed, Oct 15, 2003 at 05:50:38PM +0400, Nikita Danilov wrote: > > Erik Mouw writes: > > > Nowadays disks are so incredibly cheap, that transparent compression > > > support is not realy worth it anymore (IMHO). > > > > But disk bandwidth is so incredibly expensive that compression becoming > > more and more useful: on compressed file system bandwidth of user-data > > transfers can be larger than raw disk bandwidth. It is the same > > situation as with allocation of disk space for files: disks are cheap, > > but storing several files in the same block becomes more advantageous > > over time. > > You have a point, but remember that modern IDE drives can do about > 50MB/s from medium. I don't think you'll find a CPU that is able to > handle transparent decompression on the fly at 50MB/s, even not with a > simple compression scheme as used in NTFS (see the NTFS docs on > SourceForge for details). Trend is that CPU is getting faster and faster with respect to the disk. So, even if it were hard to find such a CPU to-day, it will be common place to-morrow. > > > Erik > > PS: let me guess: among other things, reiser4 comes with transparent > compression? ;-) Yes, it will. > Nikita.