From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Kirkwood Subject: Re: Slow ceph fs performance Date: Fri, 28 Sep 2012 11:40:07 +1200 Message-ID: <5064E3D7.6080002@catalyst.net.nz> References: <201209262054.q8QKsfwx007341@ayesha.phys.virginia.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from bertrand.catalyst.net.nz ([202.78.240.40]:46076 "EHLO mail.catalyst.net.nz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754952Ab2I0XkL (ORCPT ); Thu, 27 Sep 2012 19:40:11 -0400 In-Reply-To: <201209262054.q8QKsfwx007341@ayesha.phys.virginia.edu> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: bryan@Virginia.EDU Cc: "Bryan K. Wright" , Mark Nelson , ceph-devel@vger.kernel.org Bryan - Note that the default block size for the rados bench is 4MB...and performance decreases quite dramatically with smaller block sizes (-b option to rados bench). On 27/09/12 08:54, Bryan K. Wright wrote: > > The rados benchmark was run on one of the OSD > machines. Read and write results looked like this (the > objects size was just the default, which seems to be 4kB): > > # rados bench -p pbench 900 write > Total time run: 900.549729 > Total writes made: 33819 > Write size: 4194304 > Bandwidth (MB/sec): 150.215 > > Stddev Bandwidth: 16.2592 > Max bandwidth (MB/sec): 212 > Min bandwidth (MB/sec): 84 > Average Latency: 0.426028 > Stddev Latency: 0.24688 > Max latency: 1.59936 > Min latency: 0.06794 > > # rados bench -p pbench 900 seq > Total time run: 900.572788 > Total reads made: 33676 > Read size: 4194304 > Bandwidth (MB/sec): 149.576 > > Average Latency: 0.427844 > Max latency: 1.48576 > Min latency: 0.015371 > > > >