Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757925AbYHUMww (ORCPT ); Thu, 21 Aug 2008 08:52:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754888AbYHUMwm (ORCPT ); Thu, 21 Aug 2008 08:52:42 -0400 Received: from rgminet01.oracle.com ([148.87.113.118]:59200 "EHLO rgminet01.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753902AbYHUMwl (ORCPT ); Thu, 21 Aug 2008 08:52:41 -0400 Subject: Re: [PATCH RFC] nilfs2: continuous snapshotting file system From: Chris Mason To: Szabolcs Szakacsits Cc: Ryusuke Konishi , Andrew Morton , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org In-Reply-To: References: <20080820004326.519405a2.akpm@linux-foundation.org> <200808201613.AA00212@capsicum.lab.ntt.co.jp> Content-Type: text/plain Date: Thu, 21 Aug 2008 08:51:31 -0400 Message-Id: <1219323091.7854.45.camel@think.oraclecorp.com> Mime-Version: 1.0 X-Mailer: Evolution 2.22.2 Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: AAAAAQAAAAI= X-Brightmail-Tracker: AAAAAQAAAAI= X-Whitelist: TRUE X-Whitelist: TRUE Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1280 Lines: 31 On Thu, 2008-08-21 at 00:25 +0300, Szabolcs Szakacsits wrote: > On Thu, 21 Aug 2008, Ryusuke Konishi wrote: > > >> Some impressive benchmark results on SSD are shown in [3], > > > > > >heh. It wipes the floor with everything, including btrfs. > > It seems the benchmark was done over half year ago. It's questionable how > relevant today the performance comparison is with actively developed file > systems ... > I'd expect that nilfs continues to win postmark. Btrfs splits data and metadata into different parts of the disk, so at best btrfs is going to produce two streams of writes into the SSD while nilfs is doing one. Most consumer ssds still benefit from huge writes, and so nilfs is pretty optimal in that case. The main benefit of the split for btrfs is being able to have different duplication policies for metadata and data, and faster fsck times because the metadata is more compact. Over time that may prove less relevant on SSD, and changing it in btrfs is just flipping a few bits during allocation. -chris -- 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/