From: Justin Piszcz Subject: Re: mdadm software raid + ext4, capped at ~350MiB/s limitation/bug? Date: Sun, 28 Feb 2010 10:03:04 -0500 (EST) Message-ID: References: <20100228080100.092c24c2@notabene.brown> <4B89B44A.70005@tmr.com> <170fa0d21002280633x2ea6a281tf53996834c46d831@mail.gmail.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; CHARSET=US-ASCII; FORMAT=flowed Cc: Bill Davidsen , Neil Brown , linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, linux-ext4@vger.kernel.org, Alan Piszcz To: Mike Snitzer Return-path: Received: from lucidpixels.com ([75.144.35.66]:39194 "EHLO lucidpixels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S968671Ab0B1PDG (ORCPT ); Sun, 28 Feb 2010 10:03:06 -0500 In-Reply-To: <170fa0d21002280633x2ea6a281tf53996834c46d831@mail.gmail.com> Content-ID: Sender: linux-ext4-owner@vger.kernel.org List-ID: On Sun, 28 Feb 2010, Mike Snitzer wrote: > On Sun, Feb 28, 2010 at 4:45 AM, Justin Piszcz wrote: [ .. ] > > How did you format the ext3 and ext4 filesystems? > > Did you use mkfs.ext[34] -E stride and stripe-width accordingly? > AFAIK even older versions of mkfs.xfs will probe for this info but > older mkfs.ext[34] won't (though new versions of mkfs.ext[34] will, > using the Linux "topology" info). Yes and it did not make any difference: http://lkml.org/lkml/2010/2/27/77 Incase anyone else wants to try too, you can calculate by hand, or if you are in a hurry, I found this useful: http://busybox.net/~aldot/mkfs_stride.html I believe there is something fundamentally wrong with ext4 when performing large sequential I/O when writing, esp. after Ted's comments. Justin.