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 19:48:44 +0100 Message-ID: <50980A0C.7010200@profihost.ag> References: <50979779.3040300@profihost.ag> 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]:46188 "EHLO mail.profihost.ag" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932107Ab2KESss (ORCPT ); Mon, 5 Nov 2012 13:48:48 -0500 In-Reply-To: <50979779.3040300@profihost.ag> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: "ceph-devel@vger.kernel.org" Cc: alexandre DERUMIER 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. Greets, Stefan