From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dennis Jacobfeuerborn Subject: What would a good OSD node hardware configuration look like? Date: Mon, 05 Nov 2012 18:13:33 +0100 Message-ID: <5097F3BD.2000904@conversis.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mail4.conversis.de ([213.203.219.181]:38284 "EHLO mail4.conversis.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754523Ab2KERjq (ORCPT ); Mon, 5 Nov 2012 12:39:46 -0500 Received: from nexus.conversis.de (p5DCF725E.dip.t-dialin.net [93.207.114.94]) by mail4.conversis.de (Postfix) with ESMTP id 1C2944C80020 for ; Mon, 5 Nov 2012 18:13:34 +0100 (CET) Sender: ceph-devel-owner@vger.kernel.org List-ID: To: ceph-devel@vger.kernel.org Hi, I'm thinking about building a ceph cluster and I'm wondering what a good configuration would look like for 4-8 (and maybe more) 2HU 8-disk or 3HU 16-disk systems. Would it make sense to make each disk an individual OSD or should I perhaps create several raid-0 and create OSDs from those? Also what is the best setup for the journal? If I understand it correctly then each OSD needs its own journal and that should be a separate disk but that would be quite wasteful it seems. Would it make sense to put in two small SSD disks in a raid-1 configuration and create a filesystem for each OSD journal on it? How does the number of OSDs/Nodes affect the performance of say a single dd operation? Will blocks be distributed over the cluster and written/read in parallel or does the number only improve concurrency rather than benefit single threaded workloads? Regards, Dennis