From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262608AbTJOO1l (ORCPT ); Wed, 15 Oct 2003 10:27:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263265AbTJOO1l (ORCPT ); Wed, 15 Oct 2003 10:27:41 -0400 Received: from users.linvision.com ([62.58.92.114]:27071 "HELO bitwizard.nl") by vger.kernel.org with SMTP id S262608AbTJOO1j (ORCPT ); Wed, 15 Oct 2003 10:27:39 -0400 Date: Wed, 15 Oct 2003 16:27:38 +0200 From: Erik Mouw To: Nikita Danilov Cc: Josh Litherland , linux-kernel@vger.kernel.org Subject: Re: Transparent compression in the FS Message-ID: <20031015142738.GG24799@bitwizard.nl> References: <1066163449.4286.4.camel@Borogove> <20031015133305.GF24799@bitwizard.nl> <16269.20654.201680.390284@laputa.namesys.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <16269.20654.201680.390284@laputa.namesys.com> User-Agent: Mutt/1.3.28i Organization: Harddisk-recovery.com Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 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). Erik PS: let me guess: among other things, reiser4 comes with transparent compression? ;-) -- +-- Erik Mouw -- www.harddisk-recovery.com -- +31 70 370 12 90 -- | Lab address: Delftechpark 26, 2628 XH, Delft, The Netherlands | Data lost? Stay calm and contact Harddisk-recovery.com