From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Priebe - Profihost AG Subject: Re: poor OSD performance using kernel 3.4 => problem found Date: Thu, 31 May 2012 14:18:59 +0200 Message-ID: <4FC761B3.1090200@profihost.ag> References: <4FBE415E.8030702@profihost.ag> <4FC54CDB.1000506@inktank.com> <4FC5BF27.5060704@profihost.ag> <4FC5C941.6010105@profihost.ag> <4FC5FEC1.90103@profihost.ag> <4FC60FC8.207@inktank.com> <4FC61596.3050703@profihost.ag> <4FC62BB0.1020003@inktank.com> <4FC66A1F.1080407@profihost.ag> <4FC68CAA.9030708@profihost.ag> <4FC7197D.5010406@profihost.ag> <4FC725F0.9040207@profihost.ag> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail.profihost.ag ([85.158.179.208]:37177 "EHLO mail.profihost.ag" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756895Ab2EaMTB (ORCPT ); Thu, 31 May 2012 08:19:01 -0400 In-Reply-To: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Stefan Majer Cc: Mark Nelson , yehuda@inktank.com, "ceph-devel@vger.kernel.org" Hi Mark, Hi Stefan, i found a way to solve it by comparing /proc/sys/net with an patched and an unpatched kernel. Strangely the problem occours when the values are too big (in new kernel). With the smaller values everything works fine even under 3.4. Any ideas how that can be? I thought these values should be tuned to a maximum for max performance. - => old kernel + => new kernel -/proc/sys/net/ipv4/tcp_rmem:4096 87380 6291456 +/proc/sys/net/ipv4/tcp_rmem:4096 87380 514873 -/proc/sys/net/ipv4/tcp_wmem:4096 16384 4194304 +/proc/sys/net/ipv4/tcp_wmem:4096 16384 514873 Stefan