On Thu, Jun 10, 2010 at 5:40 PM, <lrhorer@xxxxxxxxxxx> wrote: > > I thought I had sent this previously, but I don't see a reflection > copy in my in-box. Pardon me if this is a duplicate, but OTOH, if it is, > doesn't anyone have any comments or advice? I'm especially a little fuzzy > around step 4 below. I think I need to run `grub-setup` or something, but > I'm not clear on the details. > > Dilemma: GRUB legacy will not upgrade to GRUB2 on my machines. The > systems were originally built to "fake out" GRUB legacy by using a 1.0 > superblock on a pair of RAID1 members and pointing GRUB to one or the other > of the disks so it can chain load from what it thinks is an ordinary primary > partition. Once initrd loads and md is active, it assembles the arrays and > then the kernel mounts / and then /boot, and booting continues normally. > > The cause: When dpkg instructs grub-pc to configure itself, it fails > because it is unable to reconcile the information in /boot/grub/menu.lst > with the hardware mounted by /etc/fstab. > > The cure? : I was thinking I should be able to comment out the > entries for /dev/md1 in /etc/fstab and /etc/mdadm/mdadm.conf, and reboot > the system. Then I think I can > > 1. Mount /dev/hda1 to /boot. > > 2. Upgrade GRUB, which should now understand both /etc/fstab and > /boot/grub/menu/lst. > > 3. Reboot to make sure it works. > > 4. Edit /boot/grub/grub.cfg and /boot/grub/device.map to let GRUB2 know it > should be booting from an array and to make sure it is loading the RAID1 > module. > > 5. Umount /boot and create a new 1.0 superblock RAID1 array using only > /dev/hda1 and a missing member. Mount the new array as /boot. > > 6. Add the new array info into /etc/mdadm/mdadm.conf and change /etc/fstab > back to mount /dev/md1. > > 7. Run update-initramfs to copy the new configuration into initrd. > > 8. Reboot and make sure GRUB2 can now boot into the new array. > > 9. Add /dev/hdb1 into the new array, and re-sync the array. > > 10. Update /etc/mdadm/mdadm.conf with the full array info, getting rid of > the missing member, and remove the reference to the old array altogether. > > 11. Run the GRUB update routine to remove the chain-load from GRUB legacy. > > 12. Run update-initramfs to copy the final configuration into the initrd (if > GRUB update doesn't already do it.) > > Is my thinking correct, here? Have I missed a step? Up until step > 9, I should be able to easily revert back to my original configuration by > simply removing the comment for the old array, forcing an assembly of the > old array using only /dev/hdb1, add back /dev/hda1, resync the array, remove > the comment from /etc/fstab and run update-initramfs. > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > IIRC Grub 1.97 ('2') supports the 0.90 metablock format but not the 1.0 metablock format. You might just backup the contents of /boot and make that small pair of partitions use the older format (re-create that array). For /boot 0.90 should be sufficient in most cases. However, I've not tested grub 2 with mdadm. Only my ubuntu laptop uses grub2; both gentoo and arch (as of the last time I looked) were still using grub legacy. In fact, if grub supports the older metablock format but not the newer maybe you should file/attach to a bug about it. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
