From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Priebe - Profihost AG Subject: Re: waiting for sub ops Date: Mon, 14 May 2012 08:36:37 +0200 Message-ID: <4FB0A7F5.6000504@profihost.ag> References: <4FACB96F.3050309@profihost.ag> <4FAFF7B0.2030400@profihost.ag> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mail.profihost.ag ([85.158.179.208]:43690 "EHLO mail.profihost.ag" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753263Ab2ENGgj (ORCPT ); Mon, 14 May 2012 02:36:39 -0400 In-Reply-To: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Sage Weil Cc: ceph-devel@vger.kernel.org >> 1.) th osd bench shows 150MB/s per osd >> 2.) iperf shows constant 930Mbit/s per eth >> 3.) when i write 16GB with dd to the ceph mount i see spikes to 450Mbit/ and >> drops to 90kb/s for long periods of time. The overall dd speed is then >> 40Mbit/s > > We were doing some btrfs performance testing this week and seeing similar > bursty behavior. (See my May 7th performance on btrfs email for some > out-of-context detail.) It currently looks like the workload we're > presenting to the fs is resulting in non-optimal writeout, but we haven't > figured out yet how we can improve that or nailed down the source for the > burstiness. How that some of the inktank launch stuff is out of the way > we'll be picking it up again and continuing to work on that this week. > > If you're interested in getting involved, ping nhm in #ceph. It would be > interesting to capture a block trace from your environment and see if > what you're seeing is what we're seeing! Thank for your information - we've holdays in germany from thursday on and i won't be available. So thanks for the offer. But if you want i can provide a trace. Just tell me how i can produce one. Thanks! Stefan