Latest Karmic kernel update = no Grub2 menu.

Discussion in 'all things UNIX' started by Ocky, Mar 18, 2010.

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  1. Ocky

    Ocky Registered Member

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    Am dual booting with Ubuntu Hardy 8.04 using the chainloader +1 method to boot Karmic from Hardy.
    Luckily I had made a bootable Grub2 CD so was able to boot into Karmic. First thing I did was to run the boot info script which told me core.img could not be located. See below:-

    sdb1: _________________________________________________________________________

    File system: ext4
    Boot sector type: Grub 2
    Boot sector info: Grub 2 is installed in the boot sector of sdb1 and
    looks at sector 5281543 of the same hard drive for
    core.img, but core.img can not be found at this
    location.

    Operating System: Ubuntu 9.10
    Boot files/dirs: /boot/grub/grub.cfg /etc/fstab /boot/grub/core.img


    (Before kernel update it looked like this:-

    File system: ext4
    Boot sector type: Grub 2
    Boot sector info: Grub 2 is installed in the boot sector of sdb1 and
    looks at sector 5281543 of the same hard drive for
    core.img, core.img is at this location on /dev/sdb and
    looks on partition #1 for /boot/grub.
    Operating System: Ubuntu 9.10
    Boot files/dirs: /boot/grub/grub.cfg /etc/fstab /boot/grub/core.img)

    So from within the running Karmic OS I reinstalled grub2 using the command sudo grub-setup --force /dev/sdb1 (for install to the partition boot sector of sdb1).
    Now the Grub2 menu displays when selecting Karmic on boot-up, but the 'Grub Loading..' message shows for about 10 secs. before the menu is displayed and the hdd sort of churns, for want of a better word, during those 10 secs.
    Running boot info script again shows that core.img is found but now looks for UUID instead of "looks on partition #1 for /boot/grub" and looks at a different sector. See below to compare:-

    sdb1: _________________________________________________________________________

    File system: ext4
    Boot sector type: Grub 2
    Boot sector info: Grub 2 is installed in the boot sector of sdb1 and
    looks at sector 6237455 of the same hard drive for
    core.img, core.img is at this location on /dev/sdb and
    looks for
    (UUID=15fa6747-0c8f-4d00-9a57-0d0820687904)/boot/grub.
    Operating System: Ubuntu 9.10
    Boot files/dirs: /boot/grub/grub.cfg /etc/fstab /boot/grub/core.img


    There is obviously something that Grub2 does not like but I am not sure how to proceed.
    Help is hereby requested. :)
     
  2. linuxforall

    linuxforall Registered Member

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  3. Ocky

    Ocky Registered Member

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    George, S.Africa
    Yes, but the thing is, as explained before, I get the grub2 menu. I didn't need the live cd to 'fix' it as I was able to boot into Karmic with a bootable grub2 cd from where I did the grub2 reinstall which resulted in having the grub2 menu back on boot-up.

    My mystery problem is this:-
    Anyway, thanks.
     
  4. linuxforall

    linuxforall Registered Member

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    ocky,

    I notice that blinking cursor in my system as well which only has Ubuntu in it, this wasn't there before but thankfully my blinking cursor is around five seconds between POST before Ubuntu boot process begins.
     
  5. Ocky

    Ocky Registered Member

    Joined:
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    Posts:
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    Location:
    George, S.Africa
    OK - all fine now. I decided to run grub-install /dev/sdb1
    This runs grub-probe, makes a new device map, builds a new core.img and calls grub-setup to install the grub boot.img and the core.img
    Then grub-mkconfig -o /boot/grub/grub.cfg (for new grub config file)

    Now I no longer have the probs. mentioned previously and grub is my friend again. :D

    Edit: In order to have the least possible frustrations with Grub2 make a bootable CD ... grub-mkrescue --overlay=/boot/grub Grub2CD.iso
    and burn the .iso with K3b or your fav. burner.
    Once one has made a bootable Grub2CD, no need for the chroot stuff. Just boot with the CD and type ... configfile /grub.cfg ... at the prompt.
    You will get the full grub2 menu that you had in the past.
    If you have had the bootable Grub2CD in a drawer for some time and have since deleted the kernels that were present when the Grub2CD was made,
    you will get a message to the effect that a kernel first has to be loaded if you use the above command.
    In this case reboot and at the prompt type:-
    grub> linux (hd0,1)/vmlinuz root=/dev/sda1
    grub> initrd (hd0,1)/initrd.img
    grub> boot
    (Replace (hd0,1) and sda1 with whatever your harddisk and boot partition numbers are)
     
    Last edited: Mar 22, 2010
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