From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Priebe - Profihost AG Subject: Re: poor OSD performance using kernel 3.4 Date: Sun, 27 May 2012 11:11:13 +0200 Message-ID: <4FC1EFB1.5090800@profihost.ag> References: <96b57450-8d24-48df-8a82-b9bec2ff3c69@mailpro> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail.profihost.ag ([85.158.179.208]:58954 "EHLO mail.profihost.ag" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751959Ab2E0JLS (ORCPT ); Sun, 27 May 2012 05:11:18 -0400 In-Reply-To: <96b57450-8d24-48df-8a82-b9bec2ff3c69@mailpro> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Alexandre DERUMIER Cc: ceph-devel@vger.kernel.org, Mark Nelson Can really nobody help? Am 25.05.2012 17:47, schrieb Alexandre DERUMIER: > Hi Stephan, > Do you have same performance with read ? Read is fine for both versions see here: 3.0.30 Write: Total time run: 30.872357 Total writes made: 1095 Write size: 4194304 Bandwidth (MB/sec): 141.874 Average Latency: 0.450187 Max latency: 2.00672 Min latency: 0.091783 Read: Total time run: 22.907021 Total reads made: 1095 Read size: 4194304 Bandwidth (MB/sec): 191.208 Average Latency: 0.333954 Max latency: 1.71987 Min latency: 0.041373 3.4.0 Write: Total time run: 124.573247 Total writes made: 647 Write size: 4194304 Bandwidth (MB/sec): 20.775 Average Latency: 3.08058 Max latency: 65.2522 Min latency: 0.089587 Read: Total time run: 13.191562 Total reads made: 647 Read size: 4194304 Bandwidth (MB/sec): 196.186 Average Latency: 0.322895 Max latency: 1.22392 Min latency: 0.043784 > Did you have done some iostats ? Yes - I/O is heavily jumping between 0 and 60MB/s but of the time it's 0 or around 10MB/s. > how much time to flush from journal to disks ? I don't know how to measure this. As ceph starts to write to journal and disk in parallel and tmpfs isn't even shown in iostat. Greets, Stefan