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keepitsimpleengineer
Asked: 2011-11-26 09:35:07 +0800 CST

grub workaround for cannot find UUID in dual boot system fails and now grub won't boot anything

  • 772

New clean install of x86 11.10 desktop. Dual boot with windows XP and Linux on separate drives.

After install grub will not boot Windows, but by changing boot drive boots fine.

When I go to fix this I find from http://bootinfoscript.sourceforge.net/ and a link to http://sourceforge.net/apps/mediawiki/bootinfoscript/index.php?title=Boot_Problems:search my problem, the message on the grub boot error screen:

error: no such device: 6⋯⋯⋯⋯⋯⋯⋯

So I follow the Step2 and compare the output of:

sudo blkid and

sudo nano /boot/grub/grub.cfg

The UUIDs in both match for the Windows drive, so I do the fix in Step 4 "remove the search lines for …" in /usr/lib/grub/grub-mkconfig_lib, commenting out the three lines as before⋯

# if fs_uuid="`${grub_probe} --device ${device} --target=fs_uuid 2> /dev/null`" ; then
# echo "search --no-floppy --fs-uuid --set ${fs_uuid}"
# fi

I run sudo update-grub and check /etc/default/grub.cfg and see that it now identifies the Windows partition not by UUID, which I suppose is the workaround.

But now when I try to boot 11.10 Desktop, I get:

error: no such partition… …

and when I try to boot Windows, I get:

error: invalid signature.

So Now, how do I fix this…

The boot problem and find a workaround that works?

11.10

3 Answers

  1. Best Answer

    Well, since it really is a two part question, I can answer the implicit first one about how to get grub2 to at least boot ubuntu.

    It goes like this:

    • Boot from LiveCD (x86 11.10 Desktop)

    • Mount the root of the Ubuntu 10.10 at /mnt

    • Change root

    • Remove workaround changes to /usr/lib/grub/grub-mkconfig_lib

    • Run update-grub

    • Reboot

    The above steps are from near the bottom of the Ubuntu Community Documentation of Grub2

    ⋯the particulars are by example after booting from CD and running in terminal…

    sudo -i ⋯ I've spent too many years as su, but you shold use "sudo …" in front of each command

    ubuntu@ubuntu:~$ sudo -i

    fdisk -l ⋯ that's a lower case L ⋯ Find the 11.10 installation partitions, (other disks snipped here)

    fdisk -l

⋯ ⋯ ⋯

Disk /dev/sde: 300.1 GB, 300089646592 bytes
255 heads, 63 sectors/track, 36483 cylinders, total 586112591 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xc3f5ebeb

Device    Boot      Start         End      Blocks   Id  System
/dev/sde2       138464296   586110975   223823340    5  Extended
/dev/sde3   *        2048   138463231    69230592   83  Linux
/dev/sde5       138464298   313460279    87497991    7  HPFS/NTFS/exFAT
/dev/sde6       313460736   317650943     2095104   82  Linux swap / Solaris
/dev/sde7       317652992   581922815   132134912   83  Linux
/dev/sde8       581924864   586110975     2093056   82  Linux swap / Solaris

Partition table entries are not in disk order

    mount /dev/sde3 /mnt ⋯ my root partition, sde7 is my home partition

    ls /mnt ⋯ just checking to see if I got it right

    root@ubuntu:~# mount /dev/sde3 /mnt
root@ubuntu:~# ls /mnt
bin   cdrom  etc   initrd.img      lib         media  opt   root  sbin     srv  tmp  var      vmlinuz.old
boot  dev    home  initrd.img.old  lost+found  mnt    proc  run   selinux  sys  usr  vmlinuz

    for i in /dev /dev/pts /proc /sys; do sudo mount -B $i /mnt$i; done ⋯ do as one line

    chroot /mnt ⋯ change the root

    sudoedit /usr/lib/grub/grub-mkconfig_lib ⋯ here I undo the changes

    update-grub ⋯ now update grub

    root@ubuntu:~# for i in /dev /dev/pts /proc /sys; do sudo mount -B $i /mnt$i; done
root@ubuntu:~# chroot /mnt
root@ubuntu:/# sudoedit /usr/lib/grub/grub-mkconfig_lib
root@ubuntu:/# update-grub
Generating grub.cfg ...
Found linux image: /boot/vmlinuz-3.0.0-13-generic
Found initrd image: /boot/initrd.img-3.0.0-13-generic
Found linux image: /boot/vmlinuz-3.0.0-12-generic
Found initrd image: /boot/initrd.img-3.0.0-12-generic
Found memtest86+ image: /boot/memtest86+.bin
Found Microsoft Windows XP Professional on /dev/sdc1
done

    sudoedit /etc/default/grub ⋯ check to see if changed (should be same as the original)

    sudoedit /boot/grub/grub.cfg ⋯ check to see if mounting by UUID as originally

    And it was.

    Now to file a bug report for the boot failure…

    • 3

  2. Grub now functions as expected and both WinXP and Ubuntu 11.10 now boot correctly.

    This is inexplicable as no changes were made to Grub except normal upgrades.

    • 0

  3. This is inexplicable as no changes were made to Grub except normal upgrades.

    I am a noob that just installed a duel boot win10 and Ubuntu Gnome current one. And the Grub 2 worked many times while configuring the duel boot. The grub 2 worked, and I didn't have to add apci or acpi etc..

    After I got the boot working; I used win10debloater https://github.com/Sycnex/Windows10Debloater

    Then upgraded the win10 using Windows Update and I noticed that the System Bios has changed as I had to re-do the bios.

    I too agree, that the Grub didn't change; it is my guess (not knowing a thing about ubuntu) that the UUID has changed.

    So I am guessing that if the UUID changed once Win10 is updated and the link to the UUID is confirmed.

    This has been going on for a long time, and I believe it is the System Bios being changed by win10; because if Ubuntu ever created an easy install windows knows that everything can change over night.

    Delete this if I am in error, please.

    • 0