On Thu, Mar 29, 2012 at 3:12 PM, Braden McDaniel <braden@xxxxxxxxxxxxx> wrote: > I've had an rpm upgrade from Fedora 15 tio 16 go slightly sideways and I've > wound up with a grub prompt upon boot. I found > <https://fedoraproject.org/wiki/GRUB_2>; alas, it seems to be missing > information about what one does when one's root partition is on an LVM > volume. By "rpm upgrade" I assume you mean yum upgrade? Yum upgrades don't update the bootloader to GRUB2, only anaconda/preupgrade is smart enough to figure that out, so the only way you'd be running GRUB2 is if you updated it manually. GRUB1 is *supposed* to still work fine in the interim, though apparently that didn't work out so well for you. ;-) The good news here is that GRUB1 knew nothing about LVM, so you have to have a seperate /boot partition, which is all GRUB cares about. Fedora's initramfs does the hard work with LVM. So even though GRUB2 now speaks LVM, it doesn't have to deal with it in your case. > Do I need a Live CD to recover at this point? Yes, that would be best. Make sure it matches the arch of the installed system so you can chroot into your installation if necessary. The prescription for repairing your bootloader from should be something like this: Become root. `sudo` doesn't work on Fedora live media so just: su - Activate your LVM volumes: vgchange -a y lvchange -a y Mount your root partition somewhere (run `lvdisplay` if you're not sure of the device path): mkdir /mnt/root mount /dev/mapper/vg_hostname-lv_root /mnt/root Mount your /boot partition into it (run `print all` in `parted` if your not sure of the device): mount /dev/sdX# /mnt/root/boot Verify that your boot partition is copacetic. Make sure there's a kernel and initramfs that has .fc16 in it:. Then, check /etc/default/grub and make sure that the GRUB_CMDLINE_LINUX variable mentions your LVM logical volume. There should be a kernel argument that looks like "rd.lvm.lv=vg_hostname/lv_root" If there is not, copy the one from /mnt/root/boot/grub/menu.lst or add one in that format that matches your configuration. Now you can install GRUB2: grub2-install --boot-directory=/mnt/root/boot Next, chroot into your root paritition. (I think grub2-mkconfig is smart enough to not need this, but still, it can't hurt.) chroot /mnt/root Generate a grub configuration file. (Remember, you're chrooted now so /boot is your real boot, not the live media's.) grub2-mkconfig -o /boot/grub2/grub.cfg Finally, make sure it finds the F16 kernel you verified the existence of earlier, either by looking at what grub2-mkconfig spits out to the screen or checking grub.cfg. With any luck, nothing else will go wrong and you can now reboot into F16. -T.C. -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
