From mboxrd@z Thu Jan 1 00:00:00 1970 From: Doug Ledford Subject: Re: [PATCH] 4/6: scsi_allow_ghost_devices Date: Mon, 19 Apr 2004 08:06:22 -0400 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <1082376382.4635.65.camel@compaq.xsintricity.com> References: <20040418185950.GG4868@tpkurt.garloff.de> <20040418202022.B3393@infradead.org> <1082360042.4691.3.camel@laptop.fenrus.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from mx2.redhat.com ([66.187.237.31]:58034 "EHLO mx2.redhat.com") by vger.kernel.org with ESMTP id S264376AbUDSMID (ORCPT ); Mon, 19 Apr 2004 08:08:03 -0400 In-Reply-To: <1082360042.4691.3.camel@laptop.fenrus.com> List-Id: linux-scsi@vger.kernel.org To: Arjan Van de Ven Cc: Christoph Hellwig , Kurt Garloff , Linux SCSI list , James Bottomley , Andrew Morton On Mon, 2004-04-19 at 03:34, Arjan van de Ven wrote: > > I'm very unhappy with that. Could you explain why EMC needs this? > > And even if we have to work around it I'd rather use the blacklist mechanism > > for this. > > they allow the admin to config the box without a lun 0.... > I 100% agree it's blacklist material. Actually, the original reason for the patch was the fact that some external boxes use LUN 0 as a control device that you send commands to in order to init logical volumes. Without access to the control device (which previously was always shown as offline), you couldn't set the box up with any linux tools, you would have to set up the logical volumes under Windows then boot into linux to see them. Since the LUN 0 device wasn't really offline, but instead was reported as a disk device with no attached physical device, this patch was created to allow the linux kernel to send commands to the control device. -- Doug Ledford 919-754-3700 x44233 Red Hat, Inc. 1801 Varsity Dr. Raleigh, NC 27606