From: Chris Mason Subject: Re: getdents - ext4 vs btrfs performance Date: Thu, 1 Mar 2012 09:18:23 -0500 Message-ID: <20120301141823.GV5054@shiny> References: <20120229144244.GF5054@shiny> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Hillf Danton , linux-ext4@vger.kernel.org, linux-fsdevel , LKML , linux-btrfs@vger.kernel.org, lczerner@redhat.com To: Jacek Luczak Return-path: Received: from rcsinet15.oracle.com ([148.87.113.117]:36172 "EHLO rcsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753896Ab2CAOSa (ORCPT ); Thu, 1 Mar 2012 09:18:30 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: On Thu, Mar 01, 2012 at 03:03:53PM +0100, Jacek Luczak wrote: > 2012/3/1 Hillf Danton : > > On Thu, Mar 1, 2012 at 9:35 PM, Jacek Luczak wrote: > >> > >> While I was about to grab acp I've noticed seekwatcher with made my day :) > >> > >> seekwatcher run of tar cf to eliminate writes (all done on 3.2.7): > >> 1) btrfs: http://dozzie.jarowit.net/~dozzie/luczajac/tar_btrfs.png > >> 2) ext4: http://dozzie.jarowit.net/~dozzie/luczajac/tar_ext4.png > >> 3) both merged: http://dozzie.jarowit.net/~dozzie/luczajac/tar_btrfs_ext4.png Whoa, seekwatcher makes it pretty clear. > >> > >> I will send acp results soon. > >> > > Would you please take reiserfs into account? > > As of now not (lack of time) but I'm pretty close to consider XFS in > the game. Whenever I will have more time and there won't be a pressure > on giving host back to production I will redo same tests for reiserfs. > > Now I'm focused on the userspace sorting results. reiserfs should have results very similar to ext4. The directory hashing used by reiserfs is going to result in a very random read pattern. XFS will probably beat btrfs in this test. Their directory indexes reflect on disk layout very well. -chris