[ubuntu-studio-users] How to restore the MBR after do-release-upgrade?

[Roberto Verzola]

I don't do this very often, so I don't remember the details. I seem to remember that there exists an option to boot either from MBR or from something else. Have you made sure that your system boots from the MBR?

Roberto


On Thu, 7 Jul 2016 15:03:04 +0200
Ralf Mardorf <ralf.mardorf at alice-dsl.net> wrote:

> Hi,
> 
> the    # do-release-upgrade    from Wily 15.10 to Xenial 16.04
> installed the GRUB packages. There was no way to deny the installation.
> I now try to get rid of GRUB, allegedly written to /dev/sda, by
> restoring the MBR of all connected drives.
> 
> The dd command claims to be ok, but after running
>  
>   [root at moonstudio 2016-May]# dd if=MBR_SDA-20160506_155555.may_2_0_1_6 of=/dev/sda bs=512 count=1 
>   1+0 records in
>   1+0 records out
>   512 bytes copied, 0.0138179 s, 37.1 kB/s
>   [root at moonstudio 2016-May]# echo $?
>   0
>   [root at moonstudio 2016-May]# dd if=MBR_SDB-20160506_155555.may_2_0_1_6 of=/dev/sdb bs=512 count=1 
>   1+0 records in
>   1+0 records out
>   512 bytes copied, 0.0181916 s, 28.1 kB/s
>   [root at moonstudio 2016-May]# echo $?
>   0
>   [root at moonstudio 2016-May]# cd
>   [root at moonstudio ~]# umount /dev/sdb14
>   [root at moonstudio ~]# rmdir /mnt/data2/ 
>   [root at moonstudio ~]# shutdown -r now
> 
> still the new Ubuntu GRUB menu appears. I tried several times, also
> 
>   [root at moonstudio 2016-May]# dd of=/dev/sda if=MBR_SDA-20160506_155555.may_2_0_1_6 bs=512 
>   1+0 records in
>   1+0 records out
>   512 bytes copied, 0.016662 s, 30.7 kB/s
>   [root at moonstudio 2016-May]# echo $?
>   0
>   [root at moonstudio 2016-May]# dd of=/dev/sdb if=MBR_SDB-20160506_155555.may_2_0_1_6 bs=512  
>   1+0 records in
>   1+0 records out
>   512 bytes copied, 0.0185379 s, 27.6 kB/s
>   [root at moonstudio 2016-May]# echo $?
>   0
>   [root at moonstudio 2016-May]# cd 
>   [root at moonstudio ~]# umount /dev/sdb14
>   [root at moonstudio ~]# rmdir /mnt/data2/ 
>   [root at moonstudio ~]# shutdown -r now
> 
> but I never get back the setup I used before GRUB was installed by
> do-release-upgrade.
> 
> Could somebody explain why overwriting the MBRs with data from backups
> doesn't remove GRUB from the MBR or what ever else is happening?
> 
> Regards,
> Ralf
> 
> 
> OT PS:
> 
> 
> Is there still a moderator who takes care:
> 
>   Your mail to 'ubuntu-studio-users' with the subject
> 
>       foo
> 
>   Is being held until the list moderator can review it for approval.
> 
>   The reason it is being held:
> 
>       Post by non-member to a members-only list
> 
> 
> If I use the wrong account, I cancel the posting, but other users might
> wait for approval.
> 
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-- 
Roberto Verzola <rverzola at gn.apc.org>