Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758905AbYFQOGy (ORCPT ); Tue, 17 Jun 2008 10:06:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757535AbYFQOGo (ORCPT ); Tue, 17 Jun 2008 10:06:44 -0400 Received: from mtagate1.uk.ibm.com ([195.212.29.134]:55739 "EHLO mtagate1.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752862AbYFQOGn convert rfc822-to-8bit (ORCPT ); Tue, 17 Jun 2008 10:06:43 -0400 Date: Tue, 17 Jun 2008 16:06:28 +0200 From: Maxim Shchetynin To: linux-fsdevel@vger.kernel.org Cc: =?UTF-8?B?SsO2cm4=?= Engel , Jan Engelhardt , Matthew Wilcox , linux-kernel@vger.kernel.org Subject: Re: AZFS file system proposal Message-ID: <20080617160628.79efd2d9@mercedes-benz.boeblingen.de.ibm.com> In-Reply-To: <20080617105300.GA28310@logfs.org> References: <20080609104650.4f220492@mercedes-benz.boeblingen.de.ibm.com> <20080609125530.GF30405@parisc-linux.org> <20080610104919.504b9826@mercedes-benz.boeblingen.de.ibm.com> <20080617110655.59c915da@mercedes-benz.boeblingen.de.ibm.com> <20080617105300.GA28310@logfs.org> Organization: IBM Deutschland Entwicklung GmbH X-Mailer: Claws Mail 2.10.0 (GTK+ 2.12.0; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2216 Lines: 55 On Tue, 17 Jun 2008 12:53:00 +0200 Jörn Engel wrote: > On Tue, 17 June 2008 11:35:10 +0200, Jan Engelhardt wrote: > > On Tuesday 2008-06-17 11:06, Maxim Shchetynin wrote: > > > > >I would say you can either mmap it or place a file system on it. > > > > The help text implies that I *need* azfs to mmap it - and that sounds > > like a Rube Goldberg machine. > > Some people actually prefer filesystems over raw devices for a variety > of reasons: > - each file brings its own address space, which offers memory protection > from other processes, > - files can have owners and permission bits, > - files hide the fragmentation of the underlying device from users, > - a file system provides a common and well-understood api for devices > with less common or well-understood apis, > - etc. > > Those reasons are as valid for azfs as for any other filesystem. I have > no doubt that azfs is useful. It probably wouldn't hurt to express the > merits of the filesystem and the problems it is supposed to solve a > little better. So far most criticism was based on the fact that noone > understood what the hell it was all about. > > My personal question when looking at this is: Why not use ext2? It Same reason we don't use ext2 for file system in RAM - we don't need any expensive caching and readahead mechanisms for devices which are as fast as main memory (or almost as fast). > appears to me that an ext2 mounted with '-o xip' would solve the same > problems. -- Mit freundlichen Grüßen / met vriendelijke groeten / avec regards Maxim V. Shchetynin Linux Kernel Entwicklung IBM Deutschland Entwicklung GmbH Linux für Cell, Abteilung 3250 Schönaicher Straße 220 71032 Böblingen Vorsitzender des Aufsichtsrats: Johann Weihen Geschäftsführung: Herbert Kircher Sitz der Gesellschaft: Böblingen Registriergericht: Amtsgericht Stuttgart, HRB 243294 Fahr nur so schnell wie dein Schutzengel fliegen kann! -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/