From mboxrd@z Thu Jan 1 00:00:00 1970 From: Moshe Yudkowsky Subject: In this partition scheme, grub does not find md information? Date: Mon, 28 Jan 2008 22:44:50 -0600 Message-ID: <479EAF42.6010604@pobox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids I'm finding a problem that isn't covered by the usual FAQs and online recipes. Attempted setup: RAID 10 array with 4 disks. Because Debian doesn't include RAID10 in its installation disks, I created a Debian installation on the first partition of sda, in /dev/sda1. Eventually I'll probably convert it to swap, but in the meantime that 4G has a complete 2.6.18 install (Debian stable). I created a RAID 10 array of four partitions, /dev/md/all, out of /dev/sd[abcd]2. Using fdisk/cfdisk, I created the partition/dev/md/all1 (500 MB) for /boot, and the parition /dev/md/all2 with all remaining space into one large partition (about 850 GB). That larger partition contains /, /usr, /home, etc. each as a separate LVM volume. I copied usr, var, etc. (but not proc or sys, of course) files over to the raid array, mounted that array, did a chroot to its root, and started grub. I admit that I'm no grub expert, but it's clear that grub cannot "find" any of the information in /dev/md/all1. For example, grub> find /boot/grub/this_is_raid can't find a file that exists only on the raid array. Grub only searches /dev/sda1, not /dev/md/all1. Perhaps I'm mistaken but I though it was possible to do boot from /dev/md/all1. I've tried other attacks but without success. For example, also while in chroot, grub-install /dev/md/all2 does not work. (Nor does it work with the --root=/boot option.) I also tried modifications to menu.lst, adding root=/dev/md/all1 to the kernel command, but RAID array's version of menu.lst is never detected. What I do see is grub> find /boot/grub/stage1 (hd0,0) which indicates (as far as I can tell) that it's found the information written on /dev/sda1 and nothing in /dev/md/all1. Am I trying to do something that's basically impossible? -- Moshe Yudkowsky * moshe@pobox.com * www.pobox.com/~moshe