From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966795Ab0B0BId (ORCPT ); Fri, 26 Feb 2010 20:08:33 -0500 Received: from lucidpixels.com ([75.144.35.66]:37749 "EHLO lucidpixels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966723Ab0B0BIc (ORCPT ); Fri, 26 Feb 2010 20:08:32 -0500 Date: Fri, 26 Feb 2010 20:08:30 -0500 (EST) From: Justin Piszcz To: Eric Sandeen cc: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, Alan Piszcz Subject: Re: EXT4 is ~2X as slow as XFS (593MB/s vs 304MB/s) for writes? In-Reply-To: <4B886CA1.9050906@redhat.com> Message-ID: References: <4B886CA1.9050906@redhat.com> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 26 Feb 2010, Eric Sandeen wrote: > Justin Piszcz wrote: >> Hello, >> >> Is it possible to 'optimize' ext4 so it is as fast as XFS for writes? >> I see about half the performance as XFS for sequential writes. >> >> I have checked the doc and tried several options, a few of which are shown >> below (I have also tried the commit/journal_async/etc options but none >> of them get the write speeds anywhere near XFS)? >> >> Sure 'dd' is not a real benchmark, etc, etc, but with 10Gbps between 2 >> hosts I get 550MiB/s+ on reads from EXT4 but only 100-200MiB/s write. >> >> When it was XFS I used to get 400-600MiB/s for writes for the same RAID >> volume. >> >> How do I 'speed' up ext4? Is it possible? > > Aside from Dmitry's suggestion to time sync as well (although for 10G, you are > likely not leaving much in cache) I'd ask: > > What kernel version? what xfsprogs/e2fsprogs version? 2.6.33/x86_64 ii xfsprogs 3.1.1 Utilities for managing the XFS filesystem ii e2fsprogs 1.41.10-1 ext2/ext3/ext4 file system utilities > > Were the filesystems created to align with raid geometry? Only default options were used except the mount options. If that is the culprit, I have some more testing to do, thanks, will look into it. > > mkfs.xfs has done that forever; mkfs.ext4 only will do so (automatically) > with recent kernel+e2fsprogs. How recent?