From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Wu Subject: Re: Performence test on ceph v0.23 + EXT4 and Btrfs Date: Wed, 1 Dec 2010 09:35:44 +0800 Message-ID: <1291167344.1809.60.camel@cephhost> References: <1291001135.1872.106.camel@cephhost> <1291085741.1809.25.camel@cephhost> <1291097975.1809.54.camel@cephhost> Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from [210.22.136.227] ([210.22.136.227]:56211 "EHLO MAIL.TNSOFT.COM.CN" rhost-flags-FAIL-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1753425Ab0LABeg (ORCPT ); Tue, 30 Nov 2010 20:34:36 -0500 In-Reply-To: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Gregory Farnum Cc: "ceph-devel@vger.kernel.org" , Andrew Lv =E5=9C=A8 2010-12-01=E4=B8=89=E7=9A=84 01:07 +0800=EF=BC=8CGregory Farn= um=E5=86=99=E9=81=93=EF=BC=9A > On Mon, Nov 29, 2010 at 10:19 PM, Jeff Wu wrote: > > Is "40-50MB/s" the speed that it run bench at local btrfs disk ? > > not the speed that run bench from client to osd server ? > > with this speed ,run bench from client to osd server ,will which g= et > > about 20~25MB/s( 40~50MB /2 )speed ? > Data on Ceph is replicated across 2 OSDs (by default; this is > configurable). So while figuring out potential performance involves a > lot of variables, in a simple case like this where you aren't bounded > by network bandwidth you'll find that your read/write performance > simply tracks the slower disk. I'd expect your Ceph tests (at least > the streaming ones) to run at 40-50MB/s. Hi Greg,thank you very much for your quickly reply. >=20 > Given that everything else is okay, I cannot stress enough that > running without a journal is going to cause significant performance > degradations. I have a hard time believing that it's responsible for > 13-second latencies, but it's possible. So how about you set up a > journal (it can just be a file or new partition on the drives you're > already using) and report back your results after you do that. :) I will add journal to ceph.conf to try it .=20 > Adding a journal to the OSDs lets them turn all their random writes > into streaming ones. > -Greg -- 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