Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932225AbVKVHv6 (ORCPT ); Tue, 22 Nov 2005 02:51:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932411AbVKVHv6 (ORCPT ); Tue, 22 Nov 2005 02:51:58 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:60321 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S932225AbVKVHv5 (ORCPT ); Tue, 22 Nov 2005 02:51:57 -0500 Date: Tue, 22 Nov 2005 07:51:48 +0000 From: Christoph Hellwig To: J?rn Engel Cc: Alfred Brons , pocm@sat.inesc-id.pt, linux-kernel@vger.kernel.org Subject: Re: what is our answer to ZFS? Message-ID: <20051122075148.GB20476@infradead.org> Mail-Followup-To: Christoph Hellwig , J?rn Engel , Alfred Brons , pocm@sat.inesc-id.pt, linux-kernel@vger.kernel.org References: <11b141710511210144h666d2edfi@mail.gmail.com> <20051121095915.83230.qmail@web36406.mail.mud.yahoo.com> <20051121101959.GB13927@wohnheim.fh-wedel.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20051121101959.GB13927@wohnheim.fh-wedel.de> User-Agent: Mutt/1.4.2.1i X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1314 Lines: 22 > o 128 bit > On 32bit machines, you can't even fully utilize a 64bit filesystem > without VFS changes. Have you ever noticed? Thought so. What is a '128 bit' or '64 bit' filesystem anyway? This description doesn't make any sense, as there are many different things that can be addresses in filesystems, and those can be addressed in different ways. I guess from the marketing documents that they do 128 bit _byte_ addressing for diskspace. All the interesting Linux filesystems do _block_ addressing though, and 64bits addressing large enough blocks is quite huge. 128bit inodes again is something could couldn't easily implement, it would mean a non-scalar ino_t type which guarantees to break userspace. 128 i_size? Again that would totally break userspace because it expects off_t to be a scalar, so every single file must fit into 64bit _byte_ addressing. If the surrounding enviroment changes (e.g. we get a 128bit scalar type on 64bit architectures) that could change pretty easily, similarly to how ext2 got a 64bit i_size during the 2.3.x LFS work. - 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/