From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 13 Nov 2002 12:17:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 13 Nov 2002 12:17:17 -0500 Received: from inet-mail4.oracle.com ([148.87.2.204]:32196 "EHLO inet-mail4.oracle.com") by vger.kernel.org with ESMTP id ; Wed, 13 Nov 2002 12:17:16 -0500 Date: Wed, 13 Nov 2002 09:24:00 -0800 From: Joel Becker To: Lars Marowsky-Bree Cc: Brian Jackson , "linux-kernel@vger.kernel.org" Subject: Re: md on shared storage Message-ID: <20021113172400.GE806@nic1-pc.us.oracle.com> References: <20021113002529.7413.qmail@escalade.vistahp.com> <20021113114641.GI19811@marowsky-bree.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20021113114641.GI19811@marowsky-bree.de> User-Agent: Mutt/1.4i X-Burt-Line: Trees are cool. Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 13, 2002 at 12:46:41PM +0100, Lars Marowsky-Bree wrote: > In short, you can do "MD", if you don't use it as "shared"; have only one node > have a given md device active at any point in time. Thus, no autostart, but > manual activation. This rules out "GFS over md", basically. RAID0 can work fine. You cannot have a persistent superblock and autostart, because then the two nodes stomp on each other. To allow anything other than this, you'd need cluster services and node locking. How to do RAID0? Have each node mkraid the RAID0 (or mdadm equiv) at boot. Because there is no persistent superblock, there is no contention to the disk. OpenGFS or OCFS can now share the nice striped volume, because they handle the locking for their data. We have, in fact, run OCFS on shared RAID0 in this fashion. Joel -- "Maybe the time has drawn the faces I recall. But things in this life change very slowly, If they ever change at all." Joel Becker Senior Member of Technical Staff Oracle Corporation E-mail: joel.becker@oracle.com Phone: (650) 506-8127