From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Nelson Subject: Re: 10/14/2014 Weekly Ceph Performance Meeting Date: Wed, 15 Oct 2014 08:26:20 -0500 Message-ID: <543E75FC.7010509@redhat.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ig0-f174.google.com ([209.85.213.174]:58557 "EHLO mail-ig0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750776AbaJON0S (ORCPT ); Wed, 15 Oct 2014 09:26:18 -0400 Received: by mail-ig0-f174.google.com with SMTP id a13so17330054igq.13 for ; Wed, 15 Oct 2014 06:26:17 -0700 (PDT) In-Reply-To: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Alexandre DERUMIER , Mark Nelson Cc: ceph-devel@vger.kernel.org On 10/15/2014 01:22 AM, Alexandre DERUMIER wrote: > Hi, > > about performance, maybe could it be great to also include client side performance ? Sure! Please feel free to add this or other topics that are useful/interesting to the etherpad. Please include your name though so we know who's brought it up. Even if we don't get to everything it will provide useful topics for the subsequent weeks. > > Currently I see 2 performance problems with librbd: > > 1) The cpu usage is quite huge. (I'm cpu bound with 8cores CPU E5-2603 v2 @ 1.80GHz, with 40000iops 4k read using fio-rbd) Interesting. Have you taken a look with perf or other tools to see where time is being spent? > > 2) in qemu, it's impossible to reach more than around 7000iops with 1 disk. (maybe is it also related to cpu or threads number). > I have also try with the new qemu iothread/dataplane feature, but it doesn't help. 1 disk meaning 1 OSD, or 1 disk meaning 1 volume on a VM? If its 1 volume, does adding another volume on the same VM help? I'm not familiar with the new qemu options, so that would be good to discuss at the meeting too! > > > > >