How do I restore my original GRUB and menu.lst?

beachboy2 · 05-05-2009, 10:50 AM

Whilst adding OS #3 (SliTaz) to my multi-boot system, I somehow managed to allow the little blighter to install its GRUB to MBR.

How do I restore my original GRUB and /boot/grub/menu.lst (which did show just Ubuntu 8.10 and antiX?

Partitions as follows:

Ubuntu 8.10 sda1 (root partition*), sda2 swap, sda3 /home

antiX sda5 (root partition), sda6 swap, sda7 /home

SliTaz sda8 (root partition), sda9 swap, sda10 /home

I have used the Ubuntu 8.10 Live CD to try to restore GRUB to MBR but I still end up with SliTaz booting from (hd0,0) and not Ubuntu 8.10.

Do I need to use Midnight Commander or similar to get my original Ubuntu/antiX GRUB back on MBR?

I do have a backup of my original Ubuntu home partition on my 2nd HDD (sdb) but I would prefer to locate the original /boot/grub/menu.lst and copy this to (hd0,0).

Any suggestions will be gratefully received.

ronlau9 · 05-05-2009, 11:52 AM

Just to be sure can you post the out come of the command fdisk - l as root and youŕe menu.lst
(hd0,0) only means the first partition of the boot HD.
Meaning if you make sdb the first boot HD during install the first partition of sdb is (hd0,0) too

farslayer · 05-05-2009, 12:54 PM

can you boot into Ubuntu with the current grub menu ?

if so then boot into Ubuntu, backup your menu.lst just in case and then install grub to the MBR using grub-install /dev/sda

if your current grub menu won't allow you to boot into Ubuntu an easy work around is to grab the supergrub boot disk, boot your PC with it and use it to boot into Ubuntu. then do the grub-install once you are in Ubuntu,

beachboy2 · 05-05-2009, 03:55 PM

farslayer,

Thanks for your reply.
The current boot menu is that of SliTaz so the standard “GRUB Restore” method, via GRUB prompt (grub>), does not change this to that of Ubuntu.

I have just downloaded SGBD and burned it to a CD.

I cannot find too much info on my particular situation at the SGBD website.
Once I have booted from the SGBD what can I expect to see? Will there be several options or what?

Is it clear how I should proceed to boot into Ubuntu?

My Ubuntu root partition is sda1, so do I use:

# grub-install /dev/sda1

instead of sda as you suggested?

Thanking you in anticipation.

yancek · 05-05-2009, 07:20 PM

Quote:

My Ubuntu root partition is sda1, so do I use:

# grub-install /dev/sda1

instead of sda as you suggested?

No. If you use sda1 it will install files to the root partition and you won't have anything in the mbr and likely no change. You haven't posted your fdisk -l output or your menu.lst. Your setup isn't clear to me. What you indicate in your first post is that you have a boot, swap and home partition for Ubuntu. Where are your system files (root) or was that just a type?

A backup of your /home partitin won't help you get your menu.lst as it is not in the /home directory, unless you made a copy and saved it there??

If your Ubuntu root partition is sda1 you can go to the Grub prompt and type:

root (hd0,0)
setup (hd0)
quit

to re-install Grub.

beachboy2 · 05-06-2009, 04:05 AM

yancek,
Thanks for your response about sda.
I have amended my original post to try to clarify matters.
sda1 is my Ubuntu root partitition, where I originally booted from. My Ubuntu GRUB originally resided on the MBR.
The Ubuntu menu.lst also took care of the booting of antiX from sda5. The GRUB for antiX resides in its root partition, sda5.
I was trying to add a third OS (SliTaz), booting from its root partition,sda8, but unfortunately I replaced the Ubuntu GRUB on MBR with the one from SliTaz.

I need to find the original file for the Ubuntu GRUB and replace the current one from
SliTaz.

I have tried the method you suggest (grub> prompt method) and all it does is put the SliTaz GRUB on MBR.

The Super Grub Disk method may work but I have never used it and I have no wish to make things even worse.

Is there a way for Midnight Commander (mc) to track down my original Ubuntu GRUB and menu.lst to replace the SliTaz ones?

To those who requested fdisk -l and menu.lst outputs, I am sorry but things are SNAFU at the moment for reasons which are too complicated to explain.

If you need further clarification, please ask.

linuxlover.chaitanya · 05-06-2009, 04:11 AM

Another way is to boot from the Ubuntu LiveCD and reinstall grub. That will give you your original grub but hopefully with newer distribution already added to menu.lst.

jschiwal · 05-06-2009, 04:17 AM

You can manually enter the "kernel" & "initrd" lines in the grub shell. Use tab completion to find the partitions & files. Then enter "boot". Once you are running Ubuntu, it will be easy to reinstall grub. Copy the stanza for SliTaz from the other menu.lst file and paste in the one for Ubuntu.

beachboy2 · 05-06-2009, 04:28 AM

Thanks for the additional replies.

Quote:

SGBD boot your PC with it and use it to boot into Ubuntu. then do the grub-install once you are in Ubuntu

farslayer,
Would you mind giving me a little more fine detail please on your suggested method?
I am armed with my SGBD and a trifle apprehensive that I am going to mess up things irretrievably if I am not VERY careful!
I appreciate your patience in this matter.

linuxlover.chaitanya,

I also tried that method and I still end up with the SliTaz GRUB to MBR.

linuxlover.chaitanya · 05-06-2009, 04:37 AM

Quote:

Originally Posted by beachboy2

linuxlover.chaitanya,

I also tried that method and I still end up with the SliTaz GRUB to MBR.

Did you install the grub on the root partition of Ubuntu? If you install it on MBR then it should definitely erase the old grub and put new one.

beachboy2 · 05-06-2009, 05:59 AM

Success at last! Apologies to linuxlover.chaitanya. In my earlier attempt using the Ubuntu Live CD I mistakenly used “setup (hd0,0)" instead of “setup (hd0)”.

For the benefit of others who may find themselves in such a situation in the future, please make a note of the following.
For other non-Ubuntu users e.g Mepis, at instruction #3 use:
type “su” and give root password (root) when requested.
1. Boot from Ubuntu Live CD.
2. Open a Terminal. (Applications > Accessories > Terminal)
Only type what is between the quote marks.
3. Type "sudo grub" which makes a GRUB prompt appear.
4. Type "find /boot/grub/stage1". You may get several responses if you have different OSs and you are multi-booting.
5. Type "root (hd0,0)". (OR, for example, “root (hd0,4)”. See 6. below)
6. Type "setup (hd0)". This will write GRUB to the MBR. If you wish to write GRUB to another OS's root partition such as sda5, then you type "(hd0,4)".
7. Type "quit".
8. Restart the system. Remove the bootable CD.

Many thanks to all who responded. I appreciate your assistance.

farslayer,
I would still like to have more details of your SGBD method please.

linuxlover.chaitanya · 05-06-2009, 06:11 AM

Good news.

farslayer · 05-06-2009, 08:55 AM

Super grub disk

The following example sorta matches your situation.

Quote:

I installed GRUB, (or LiLo), to MBR but I can't find it. I have more than one hard disk in this computer. Maybe it went to the MBR of the wrong hard disk. I want to try booting from another hard disk to find out.

1. boot your SGD floppy disk, USB disk or CD-ROM
2. English Super Grub Disk
3. Boot and Tools
4. Boot Master Boot Record (MBR)
5. Boot Master Boot Record
6. Choose a hard disk from the list

So now that you are in your system you could use the grub-install command I mentioned earlier to re-install grub from the current OS to the MBR.

Look at some of the Quick Help options..

http://users.bigpond.net.au/hermanzo...isk_Quick_Help

the SGBD is just a way to get your system back up if you botch grub. it won't change anything unless you tell it to, so read the menu options carefully before selecting.

Really a useful tool