Need automatic MBR backup before installation

Bug #633064 reported by YannUbuntu on 2010-09-08
This bug affects 13 people
Affects Status Importance Assigned to Milestone
ubiquity (Ubuntu)

Bug Description

Binary package hint: ubiquity

By default, Ubuntu installs GRUB on the MBR without creating backup of the original MBR.

This can cause many kinds of boot problems, especially if the MBR was "watermarked" (consequence can be : the computer cannot start, or the OEM windows in dual-boot cannot start).

As the MBR is very small (only 512 byte), it would cost nothing to save it automatically before installing GRUB. Then people who care about it could save it on external device.

Target location of this backup should be determined (e.g. Lilo automatically saves it in /boot ).

See also

YannUbuntu (yannubuntu) wrote :

After discussion on the ubuntu-fr forum (, it seems that the first 404 bytes of the original MBR are automatically saved in /usr/lib/syslinux/mbr.bin .

Can someone confirm ?

(If yes, the MBR can be restored (without the partition table) by the following command :
sudo dd if=/dev/sda of=/home/$USER/mbr_linux.bin bs=404 count=1

YannUbuntu (yannubuntu) wrote :

After checking on a real installation ( :
the 3 following are different :
I) MBR before installation
II) MBR in /usr/lib/syslinux/mbr.bin
III) MBR after installation

Conclusion : /usr/lib/syslinux/mbr.bin is not a backup of the original MBR. So this bug report is still valid.

pierguiard (pierguiard-gmail) wrote :

This bug affects all dual boot installations, particularly Windows 7 and Vista.
It is urgent to propose an automatic backup of the MBR.
A dual boot installation is already quite a headache for a beginner
Lire phonétiquement

YannUbuntu (yannubuntu) wrote :

We (ubuntu-fr) developped and heavily tested a tool that solves this bug : see bug #747279 , it is now ready for inclusion in the live-CD.

Launchpad Janitor (janitor) wrote :

Status changed to 'Confirmed' because the bug affects multiple users.

Changed in ubiquity (Ubuntu):
status: New → Confirmed
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