From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757162AbXGHUPZ (ORCPT ); Sun, 8 Jul 2007 16:15:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755455AbXGHUPM (ORCPT ); Sun, 8 Jul 2007 16:15:12 -0400 Received: from [84.243.56.243] ([84.243.56.243]:51293 "EHLO aurora.bayour.com" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1755206AbXGHUPK (ORCPT ); Sun, 8 Jul 2007 16:15:10 -0400 From: Turbo Fredriksson To: linux-kernel@vger.kernel.org Cc: Neil Brown , Alasdair G Kergon Subject: Re: Moving MD/LVM from PPC to x86 Organization: Bah! References: <87wsxneqs0.fsf@pumba.bayour.com> <20070629215416.GA12786@agk.fab.redhat.com> <876455erlw.fsf@pumba.bayour.com> <18054.9063.45466.586046@notabene.brown> X-PGP-Fingerprint: B7 92 93 0E 06 94 D6 22 98 1F 0B 5B FE 33 A1 0B X-PGP-Key-ID: 0x788CD1A9 X-URL: http://www.bayour.com/ Date: Sun, 08 Jul 2007 22:15:03 +0200 In-Reply-To: <18054.9063.45466.586046@notabene.brown> (Neil Brown's message of "Sat, 30 Jun 2007 19:33:27 +1000") Message-ID: <873azy4pq0.fsf@pumba.bayour.com> User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/22.0.95 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Quoting Neil Brown : > Version 0.90 MD superblocks (still the default) uses host-endian > values so you cannot move between architectures directly. However > isn't too hard to make it work. > Firstly, use > mdadm --examine --metadata=0.swap /dev/DEVICE ----- s n i p ----- ppc:~# mdadm --examine --metadata=0.swap /dev/md0 mdadm: No super block found on /dev/md0 (Expected magic a92b4efc, got 00000000) ppc:~# mdadm --examine --metadata=0.swap /dev/md1 mdadm: No super block found on /dev/md1 (Expected magic a92b4efc, got 00000000) ppc:~# mdadm --examine --metadata=0.swap /dev/md2 mdadm: No super block found on /dev/md2 (Expected magic a92b4efc, got 00000000) ppc:~# mdadm --examine --metadata=0.swap /dev/sda1 mdadm: No super block found on /dev/sda1 (Expected magic a92b4efc, got fc4e2ba9) ppc:~# mdadm --examine --metadata=0.swap /dev/sda mdadm: No super block found on /dev/sda (Expected magic a92b4efc, got 00000000) ppc:~# mdadm --examine --metadata=0.swap /dev/sdb mdadm: No super block found on /dev/sdb (Expected magic a92b4efc, got 00000000) ppc:~# mdadm --examine --metadata=0.swap /dev/sdb1 mdadm: No super block found on /dev/sdb1 (Expected magic a92b4efc, got fc4e2ba9) ppc:~# mdadm --examine --metadata=0.swap /dev/sdc mdadm: No super block found on /dev/sdc (Expected magic a92b4efc, got 00000000) ppc:~# mdadm --examine --metadata=0.swap /dev/sdc1 mdadm: No super block found on /dev/sdc1 (Expected magic a92b4efc, got fc4e2ba9) ppc:~# cat /proc/mdstat | grep ^md md2 : active raid1 sdb1[0] md1 : active raid1 sdc1[0] md0 : active raid1 sda1[0] ----- s n i p ----- Now what? > to check that you have the right devices. > Then > > mdadm --assemble /dev/md0 --update=byteorder /dev/DEV0 /dev/DEV1 .... > > That should assemble the array and update the superblocks so that they > are in the right byteorder and will assemble easily in future. Is this safe, changing the byteorder on all the physical devices (that are part of my MD's)? Will it still work on the PPC?