From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Priebe Subject: Re: massive rbd speed decrease with latest git master Date: Mon, 05 Nov 2012 20:03:11 +0100 Message-ID: <50980D6F.9010905@profihost.ag> References: <50979779.3040300@profihost.ag> <50980A0C.7010200@profihost.ag> <50980C64.8050501@inktank.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail.profihost.ag ([85.158.179.208]:45615 "EHLO mail.profihost.ag" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753506Ab2KETDO (ORCPT ); Mon, 5 Nov 2012 14:03:14 -0500 In-Reply-To: <50980C64.8050501@inktank.com> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Mark Nelson Cc: "ceph-devel@vger.kernel.org" , alexandre DERUMIER Am 05.11.2012 19:58, schrieb Mark Nelson: > On 11/05/2012 12:48 PM, Stefan Priebe wrote: >> Am 05.11.2012 11:39, schrieb Stefan Priebe - Profihost AG: >>> Hello list, >>> >>> while updating ceph to the latest master i noticed this: >>> >>> Commit a01b112d71a0b6a1bb206d53867d13536d17bbf6: >>> rand. 4k WRITE: 3000 iop/s >>> >>> Commit 72a710ac47355ae3ca1d055be1496c91956d549d: >>> rand. 4k WRITE: 900 iop/s >>> >>> Same for rand 4k read - haven't tested sequential stuff. >> >> OK i found out what the issue is. I get 900 iop/s when compiled with >> syncfs support and i get 3000-6000 iop/s when compiled without syncfs >> support. >> >> Strange shouldn't syncfs improve the performance? >> >> Note: ceph is running inside KVM right now for testing with an iscsi >> based backend storage. My real testhw will arrive tomorrow. > > Very strange. I'm curious if you continue to see this on your real test > hardware. Yes - will report back tomorrow. Stefan