[Bug 495423] Re: update to grub-pc writes MBR without checks, prompt or backup

[Jeremy Visser]

On 19/11/2012 02:07, Phillip Susi wrote:
> As the previous comment indicated, grub checks to make sure the drives
> are the same that were selected before, and if not, prompts again.

I was thinking more along the lines of linking to Debian changelog 
entries and specifying the actual package names/versions that the fix 
was released in, rather than anecdotes.

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to grub2 in Ubuntu.
https://bugs.launchpad.net/bugs/495423

Title:
  update to grub-pc writes MBR without checks, prompt or backup

Status in “grub2” package in Ubuntu:
  Fix Released

Bug description:
  Binary package hint: grub

  Booted laptop from external USB HDD containing Karmic.

  Installed updates. One of the updates is to grub.

  Internal drive contains a full-disk encrypted Windows installation.

  Update to grub writes the grub MBR to the internal disk, instead of
  the disk that grub booted the original MBR from.

  On a standard Windows install I would have considered this merely
  annoying, because I could have replaced the MBR easily enough. On this
  install I have to get one of the support techs to "bless" the disk
  with a special bootloader and the "Code of the Day".

  This is a more general case of #112239 "GRUB writes to wrong MBR and
  destroys RAID setup"

  Suggestions ;

   - Where multiple disks present, always prompt the user for the disk to put the MBR on. This would help prevent these problems 
     - Make the prompt nice and clear, disk descriptors, sizes, etc
   - When UPDATING grub, only write the MBR to a disk that has a recognized grub MBR on it already.
     - It's not an "install" (and be damned), it's an update
   - Whenever you write any MBR, write the previous MBR data to a permanent log file. This way it can be restored afterwards.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/495423/+subscriptions