From mboxrd@z Thu Jan 1 00:00:00 1970 From: "K. Richard Pixley" Subject: Re: simple performance tests Date: Wed, 16 Jun 2010 10:58:01 -0700 Message-ID: <4C1910A9.4030305@noir.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from m209-5.dsl.rawbw.com ([198.144.209.5]:33222 "EHLO kyoto.noir.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756492Ab0FPSGa (ORCPT ); Wed, 16 Jun 2010 14:06:30 -0400 In-Reply-To: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Thomas Mueller Cc: ceph-devel@vger.kernel.org Hi. I've been running some similar tests recently, (on ubuntu, but still). Thomas Mueller wrote: > dbench 1 results: > * 1 disk, btrfs: 115 > * 2 disks, btrfs data/metadata raid0: 115 > This is suspicious. I'm also not sure whether you mean that you're running btrfs on an md or lvm stripe or using multiple device btrfs file systems. My numbers are showing that btrfs multidevice support may not be very good right now but I get pretty good results from lvm stripes. The hardware I'm testing now is the first hardware I've tried, (of prolly a couple dozen over the years), where the controller can actually keep all disks spinning. Most cannot. Try building an lvm stripe on your two disks and testing dd directly to the stripe. --rich