[Bug 1061255] Re: GRUB recognizes defunct LDM headers

[João Rossa]

Do i need to recover the windows 7 boot first and then run liveCD ?Do i
do what you said here:


"It is actually the backup copy at the end of the disk that appears to be the problem. Zeroing out the last sector of the disk should fix it. To do this, you want to follow steps similar to this:

sudo fdisk -lu /dev/sda

Disk /dev/sda: 250.1 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders, total 488397168 sectors

Note the sector count. Subtract one and that leaves 488397167, which you
can then use with dd to dump that sector:

sudo dd if=/dev/sda bs=512 count=1 skip=488397167 | hd

At this point you should see somewhere on the screen the string
"PRIVHEAD". If you do, that is the LDM label sector. You can then zero
it out with:

sudo dd if=/dev/zero of=/dev/sda bs=512 seek=488397167 count=1

It is vital that the command be executed correctly or you can trash your
whole disk, so triple check your typing and math before hitting enter."

After doing all this i should use the "update-grub" command?

regards,

-- 
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Foundations Bugs, which is subscribed to grub2 in Ubuntu.
https://bugs.launchpad.net/bugs/1061255

Title:
  GRUB recognizes defunct LDM headers

Status in “grub2” package in Ubuntu:
  Triaged

Bug description:
  GRUB recognizes stale LDM headers left on the disk after reformatting
  without LDM.  This causes grub to complain either that embedding is
  not possible, and/or to incorrectly use the ldm partition module
  instead of msdos.

  - This bug affect GRUB2.00 (default bootloader of Ubuntu12.10).
  - This bug completely breaks access to any operating system, either when installing a fresh 12.10, or when upgrading from 12.04 to 12.10.

  ********************
  WORKAROUND:
  Use Boot-Repair ( https://help.ubuntu.com/community/Boot-Repair ) from liveCD to replace GRUB2 by GRUB Legacy: run Boot-Repair --> Advanced options --> GRUB options tab --> tick "GRUB Legacy" --> Apply
  ********************

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