How to restore grub?

[LittleKoy]

This is the same old story. I installed WinXP after Ubuntu, and that idiot os overwrote the bootloader. Now I want grub back.

I searched and found several guides, but they all tell me to (in a LiveCD):

grub> find /boot/grub/stage1

but I get Error 15 (file not found)

I even tried

grub> find /media/disk/boot/grub/stage1

but it still doesn't find it (which is strange, sine the file IS there).

And about root (?,?), I don't know what to put inside it. My Ubuntu / is on sda1, but if I do root (sda,0) or (sd0,0) it says error while parsing number.
If I do (hdX,0), it says that hdX is not a drive, for X=0,1,2,3,..

I'm stuck, what can I do?

[dstew]

You might have to mount the hard disk to the Live CD file system before the grub shell program can find it. Once you have the output of the grub find command, use that as the root to install grub.

If you know Ubuntu's root is /dev/sda1, a safe bet for grub's root argument is (hd0,0). Then, install the boot loader into the Master Boot Record of /dev/sda with setup (hd0):
grub> root (hd0,0)
grub> setup (hd0)
grub> quitThen, shut down the Live CD system, remove the CD from the drive, and reboot.

[LittleKoy]

I mounted it as /media/disk.

find /boot/grub/stage1 and /media/disk/boot/grub/stage1 both give error 15.
root (hd0,0) tells me "Error 21: selected disk does not exist"

[dstew]

From a Live CD system, do
sudo fdisk -land post the output to the forum.

[LittleKoy]

Disk /dev/sda: 400.0 GB, 400088457216 bytes
255 heads, 63 sectors/track, 48641 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x000810f0

Device Boot Start End Blocks Id System
/dev/sda1 1 2576 20691688+ 83 Linux
/dev/sda2 2577 46922 356209245 83 Linux
/dev/sda3 * 46923 48137 9759487+ 7 HPFS/NTFS
/dev/sda4 48138 48641 4048380 5 Extended
/dev/sda5 48139 48641 4040347+ 82 Linux swap / Solaris

Disk /dev/sdb: 120.0 GB, 120034123776 bytes
255 heads, 63 sectors/track, 14593 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0xf079e959

Device Boot Start End Blocks Id System
/dev/sdb1 1 14593 117218241 c W95 FAT32 (LBA)


The second is an USB hd, I only plug it occasionally for backup..

[dstew]

Strange, it all seems very straightforward. Did you happen to format your Linux file system as ext4? Perhaps that is causing some trouble with the grub shell program on the Live CD.

[LittleKoy]

Strange, it all seems very straightforward. Did you happen to format your Linux file system as ext4? Perhaps that is causing some trouble with the grub shell program on the Live CD.

Yes, your guess is correct..

[presence1960]

let's get an exact shot of your setup & boot info. Boot the Live Cd and download to the desktop the Boot Info Script 0.32 from here: http://sourceforge.net/projects/bootinfoscript/files/
Once DL'd open a terminal and run this command
sudo bash ~/Desktop/boot_info_script*.sh This will create a RESULTS.txt file on the desktop. paste the entire contents of the file back here, then when pasted highlight all text and click # on the toolbar to place code tags around the text. This info will shed light on a lot of things- like if and where GRUB is installed on your machine.

[presence1960]

Strange, it all seems very straightforward. Did you happen to format your Linux file system as ext4? Perhaps that is causing some trouble with the grub shell program on the Live CD.

I have ext 4 for both 9.04 Ubuntu and Sabayon 4.2 and have not had those problems. That does not mean it can not happen. Let's see what the boot info script returns when it is run.

[presence1960]

This is the same old story. I installed WinXP after Ubuntu, and that idiot os overwrote the bootloader. Now I want grub back.

I searched and found several guides, but they all tell me to (in a LiveCD):

grub> find /boot/grub/stage1

but I get Error 15 (file not found)

I even tried

grub> find /media/disk/boot/grub/stage1

but it still doesn't find it (which is strange, sine the file IS there).

And about root (?,?), I don't know what to put inside it. My Ubuntu / is on sda1, but if I do root (sda,0) or (sd0,0) it says error while parsing number.
If I do (hdX,0), it says that hdX is not a drive, for X=0,1,2,3,..

I'm stuck, what can I do?
I know this is probably a no brainer, but based on your command you posted did you preface grub with sudo? I ran it with just grub, and when i ran the find /boot/grub/stage1 I got an error 15 like you did.

[presence1960]

1. Boot your computer up with Ubuntu CD
2. Open a terminal window or switch to a tty.
3. Type sudo grub. Should get text of which last line is grub>
4. Type "find /boot/grub/stage1". You'll get a response like "(hd0,1)".
Use whatever your computer spits out for the following lines.
5. Type "root (hd0,1)", or whatever your hard disk + boot partition
numbers are for Ubuntu.
6. Type "setup (hd0)", to install GRUB to MBR, or "setup (hd0,1)" or
whatever your hard disk + partition # is, to install GRUB to a
partition.
7. Quit grub by typing "quit".
8. Reboot and remove the bootable CD.

if what you say about your partitions is accurate in #5 use root (hd0,0). In #6 use setup (hd0).

when you boot GRUB will be in the MBR and point to your menu.lst in sda1

[brookie]

I'm not a guru or anything, just a noob, but I followed this tutorial and added a dual boot winxp partition with no problems. http://apcmag.com/how_to_dualboot_vista_with_linux_linux_is_already_ installed.htm?page=6

it got my grub back in order and all worked well afterward.
good luck,
brook

[presence1960]

I'm not a guru or anything, just a noob, but I followed this tutorial and added a dual boot winxp partition with no problems. http://apcmag.com/how_to_dualboot_vista_with_linux_linux_is_already_ installed.htm?page=6

it got my grub back in order and all worked well afterward.
good luck,
brook

Right on Brookie, same thing I posted except I didn't tell how to edit menu.lst for the windows entry. One step at a time. But your post was right on the money. The OP's problem is he isn't using sudo to run the grub command, that's why he is getting error 15. Need administrative priviledge to run that grub command.

[LittleKoy]

OPS :D

Ah ah, so that was the problem... Thank you, I'm back in Ubuntu :D

[presence1960]

OPS :D

Ah ah, so that was the problem... Thank you, I'm back in Ubuntu :D

Glad to hear that! Enjoy Ubuntu. BTW reboot & check to see if you can boot into windows. if not edit your windows entry in menu.lst to this:


title Windows <your version>
rootnoverify (hd0,2)
chainloader +1