From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Leslie Rhorer" Subject: RE: Upgraded grub, now confused about mirrored /boot Date: Tue, 2 Nov 2010 09:20:32 -0500 Message-ID: <5A.0F.13137.73E10DC4@cdptpa-omtalb.mail.rr.com> References: <9770F687FAE544F295B1A22155F2BBA6@m5> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <9770F687FAE544F295B1A22155F2BBA6@m5> Sender: linux-raid-owner@vger.kernel.org To: 'Guy Watkins' , 'Linux RAID' List-Id: linux-raid.ids > -----Original Message----- > From: linux-raid-owner@vger.kernel.org [mailto:linux-raid- > owner@vger.kernel.org] On Behalf Of Guy Watkins > Sent: Tuesday, November 02, 2010 1:11 AM > To: 'Linux RAID' > Subject: Upgraded grub, now confused about mirrored /boot > > Hello, > > I upgraded my system from Red Hat FC10 to FC11. The instructions > say to run this command: > /sbin/grub-install BOOTDEVICE > > And if it fails, run this: > /sbin/grub-install --recheck /dev/sda > > However, my boot disk (/boot) is mirrored on 4 disks and I think (or hope) > all 4 are bootable. The mirrors were created at install time many years > ago > when I installed FC5. No idea if it really made more than 1 bootable. I > have assumed that if sda failed, I could still boot from sdb, sdc or sdd. > And I do understand that I might need to remove sda first, depending on > the > type of failure. Lucky for me, no drive has failed yet and I don't recall > if I tested booting off of any other disks. > > I do have this on the kernel line: > md-mod.start_dirty_degraded=1 > > So, what do I do now? Run that command on all 4 disks? Or run it on > /dev/md0? > > Oh, 4 way mirror is not because I am paranoid. I have 4 disks partitioned > alike, so I figured I would use all 4 disks just for the symmetry. OCD > maybe, but not paranoid. :) > > # df -k /boot > Filesystem 1K-blocks Used Available Use% Mounted on > /dev/md0 256586 221526 21812 92% /boot > > md0 : active raid1 sdd1[0] sda1[3] sdc1[2] sdb1[1] > 264960 blocks [4/4] [UUUU] > bitmap: 0/33 pages [0KB], 4KB chunk GRUB2 only supports RAID on 0.90 superblock arrays. If your array has other than 0.90 superblocks, it won't work, and you will need to convert to 0.90 superblocks in order to continue. Once done, you should install GRUB2 to all four drives. Test booting from all four.