From mboxrd@z Thu Jan 1 00:00:00 1970 From: Douglas Gilbert Subject: Re: [PATCH] link scsi_debug later Date: Sat, 18 Mar 2006 01:24:03 -0500 Message-ID: <441BA783.3030807@torque.net> References: <20060317124407.5f19cc09.rdunlap@xenotime.net> <20060317212924.11a86800.akpm@osdl.org> <20060317221920.3c84fc65.rdunlap@xenotime.net> Reply-To: dougg@torque.net Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from canuck.infradead.org ([205.233.218.70]:32460 "EHLO canuck.infradead.org") by vger.kernel.org with ESMTP id S1752066AbWCRGZv (ORCPT ); Sat, 18 Mar 2006 01:25:51 -0500 In-Reply-To: <20060317221920.3c84fc65.rdunlap@xenotime.net> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: "Randy.Dunlap" Cc: Andrew Morton , linux-scsi@vger.kernel.org, james.bottomley@steeleye.com Randy.Dunlap wrote: > On Fri, 17 Mar 2006 21:29:24 -0800 Andrew Morton wrote: > > >>"Randy.Dunlap" wrote: >> >>>From: Randy Dunlap >>> >>>Link scsi-debug driver after SATA so that scsi-debug does not >>>interfere with real SCSI device ordering. >>>Yes, I was bitten by this. >>> >> >>What does "bitten" mean? > > > It means that I got the usual "VFS: could not find root filesystem on > device (8,8)" (or however it is spelled). > Oh, and that I had to add netconsole to see what was causing it, > but that is easy enough to do. > > >>Is this a regression? > > > It's probably been like this ever since SATA was added (libata) > and only happens if SCSI_DEBUG=y (so I changed it to =m). > I can't say that it's a regression since this occurred on a new > machine. Ah, if scsi_debug is a module, nothing is going to load it automatically (at least the PCI subsystem won't load it). However if it is built in then it will "steal" /dev/sda (if some other SCSI LLD hasn't already got it). That would then cause a SATA driver to get /dev/sdb ... That is enough to cause a kernel parameter like "root=/dev/sda8" to flounder and give the "could not find root filesystem" error. A regression?? Hmm. Doug Gilbert