Help Mount Unmount and auto detect new partition and restore of Grub

[Gabriel M Dragffy]

On Sun, 2006-08-13 at 22:53 +0100, José Paulo Matafome Oleiro wrote:
> Hi there people, I've got few problems for you to help if you want and
> can help me. I've deleted my windows partition and installed Debian to
> take a look but Debian doesn't had the version of kernel that I need
> so I'm gonna stay with Ubuntu as the only operating system installed
> at my laptop, but now if I delete de partition of Debian, my computer
> just gives me error because I had installed grub from the Debian
> installation in the MBR (Master Boot Record) and now if I delete the
> Debian partition, Grub gave me errors I think it's error 21, so how I
> can reinstall Grub in the MBR with the menu.lst from de Ubuntu system,
> and after this I will create a partition with the free space from the
> Debian installation with the filesystem ReiserFS and then I want this
> partition to be detected my Ubuntu, but now that I had installed
> Debian, it only shows to me in System > Administration > Hard-Disks,
> the NTFS partition of my old system Windows that now doesn't exist and
> the partition of Ubuntu and Swap Partition, can you help me with this
> little problems?
> Thanks for your help in advance.
> 
> --
> Sincerely
> José Oleiro aka Matafome (#computers at irc.ptnet.org Blog do
> Matafome )
> Running Ubuntu 6.06 Dapper with XGL on Fujitsu-Siemens Model Amilo M
> 1420


Hi,
My best advice for you would be to use a live CD, for which Knoppix is
great and then boot into that and run a root shell. Mount the partition
that has your ubuntu installation read and write (just right-click on
the icon) and also make sure it is mounted first. In the terminal bring
up grub using:

# grub
and then tell grub the root to your ubuntu installation if
it's /dev/hda1 then you must use (hd0,0) since grub starts counting from
0 and not one, hence for /dev/hda1 do:

# root=(hd0,0)

Then you need to install it to the MBR to replace the existing data
using:

# setup=(hd0)

then 

# quit

That should do it. Otherwise if you have an alternate ubuntu install CD
or the DVD you can boot with that entering rescue mode. Or even a Slax
CD with the GRUB module loaded. Many options. That's just one of them
above.