From mboxrd@z Thu Jan 1 00:00:00 1970 From: Frans Pop Subject: Re: Linux mdadm superblock question. Date: Wed, 17 Feb 2010 22:29:05 +0100 Message-ID: <201002172229.07511.elendil@planet.nl> References: <201002140251.59668.volkerarmin@googlemail.com> <201002171426.47981.elendil@planet.nl> <20100217205406.GA13287@twister.home> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20100217205406.GA13287@twister.home> Content-Disposition: inline Sender: linux-raid-owner@vger.kernel.org To: Gabor Gombas Cc: Rudy Zijlstra , kyle@moffetthome.net, neilb@suse.de, babydr@baby-dragons.com, davidsen@tmr.com, volkerarmin@googlemail.com, mjevans1983@gmail.com, linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org List-Id: linux-raid.ids On Wednesday 17 February 2010, Gabor Gombas wrote: > On Wed, Feb 17, 2010 at 02:26:46PM +0100, Frans Pop wrote: > > That's simply not true, at least not for Debian. If you actually use > > the distro tools [1] the only assumptions are made at kernel > > *installation* time, not at kernel build time. > > And that's why network-booted diskless clients and virtual guests have > all sort of useless modules loaded; the HW where the kernel package was > installed in this case is very different from the HW where the kernel > will run. Interesting use case. But also a use case for which initramfs-tools probably very simply was never intended. I agree that in this case you probably want to either - have a very generic initrd that supports anything (Debian default) [1] or - provide a list of modules to include in the initrd based on knowing the hardware you want to support (e.g. using /etc/initramfs-tools/modules) and prevent including anything based on the host system. I've never really done that so I don't know if initramfs-tools has any features to support that. > If only there were a switch to prohibit ever looking at the > current machine's configuration when generating the initramfs... Did you ever file a wishlist bug report for that? > > I've been using initramfs-tools generated initrds for years without > > problems, and that includes "root on LVM on LUKS encrypted partition" > > and "root on LVM on RAID" setups. > > I've tried a couple of times to use a Debian-built initramfs with a > custom built kernel. The kernel worked fine without an initramfs (it had > everything built in), but it did not boot with the initramfs. It's obviously hard to comment on something like this without more details (which would be off-topic for this list). [1] Could still leave you with problems if the clients use something fancy for the root fs that uses info copied from /etc.