From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Priebe - Profihost AG Subject: Re: bad performance fio random write - rados bench random write to compare? Date: Tue, 03 Jul 2012 09:31:17 +0200 Message-ID: <4FF29FC5.1050002@profihost.ag> References: <4FE07B2A.7080209@profihost.ag> <5b71e1e3-b1be-4c12-897d-0bffbbcf8d33@mailpro> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail.profihost.ag ([85.158.179.208]:48524 "EHLO mail.profihost.ag" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752086Ab2GCHbT (ORCPT ); Tue, 3 Jul 2012 03:31:19 -0400 In-Reply-To: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Gregory Farnum Cc: Alexandre DERUMIER , ceph-devel@vger.kernel.org Am 02.07.2012 21:52, schrieb Gregory Farnum: > On Tue, Jun 19, 2012 at 7:05 AM, Alexandre DERUMIER wrote: >> Hi, >> Is it possible to do random write bench with rados bench command ? >> >> I have very base random write performance with 4K block size inside = qemu-kvm, >> 1000 iops/s max with 3 nodes with 3x 5 disk 15k >> (Maybe it's related to my constant disk writes, like datas are not f= lushed sequentially to disk) >> >> seekwatcher movie of 1 osd here : >> http://odisoweb1.odiso.net/random-write-4k.mpg >> >> I would like to do tests on kvm host with rados command to compare. >> (I don't have rbd module in my kvm host kernel,so I can't use fio on= the host) > > Unfortunately, nobody's implemented a random write test in rados benc= h > yet (this might be a good bug for somebody who's interested in gettin= g > in to the project =97 rados bench is pretty simple). I'd offer more > suggestions but I think we've already discussed this elsewhere. :) I think random I/O is very important for a lot of people at least for=20 people using KVM on top of ceph. Sadly i can't implement it. Stefan -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html