From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wido den Hollander Subject: Re: Ceph on just two nodes being clients - reasonable? Date: Wed, 19 Jan 2011 12:41:26 +0100 Message-ID: <1295437286.2255.25.camel@wido-desktop> References: <4D36BDF9.4030404@wpkg.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from smtp01.mail.pcextreme.nl ([109.72.87.137]:48797 "EHLO smtp01.mail.pcextreme.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753636Ab1ASLl2 (ORCPT ); Wed, 19 Jan 2011 06:41:28 -0500 In-Reply-To: <4D36BDF9.4030404@wpkg.org> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Tomasz Chmielewski Cc: ceph-devel@vger.kernel.org Hi Thomas, I think the answer is Yes and No on this question, the devs might have another approach for your situation. If you would do this, you would have a MON, MDS and OSD on every server, in theory that would work. Mounting would be done by connecting to on of the MON's (doesn't matter which one). But Ceph requires, well, advises a odd number of monitors (Source: http://ceph.newdream.net/wiki/Designing_a_cluster ) So you would require a third node which is running your third monitor to keep track of both nodes. My advise, for two nodes, use something like DRBD in Primary <> Primary and use a cluster filesystem like OCFS2. Wido On Wed, 2011-01-19 at 11:33 +0100, Tomasz Chmielewski wrote: > Is it reasonable to set up Ceph on two nodes, which are Ceph clients at > the same time? > > > Say, we have two machines: > > ceph1 -- ceph2 > > > On each of them, Ceph filesystem is mounted in /shared, which is used by > services like a webserver or a mailserver. > > Is it a reasonable approach? > >