how to reinstall grub
 

I had Red Hat linux working I had some space on my hard drive I made another LVM partition on that free space. after making the LVMs I could not boot Linux. I get a black screen with just written

grub


I think I lost my bootloader, I rescue my system did fdisk -l removed the boot partition and made it again. i gave the command grub--install

what to do next to make grub.conf file how the process will after that.


thanks in advance

shahz

If you already ran the grub-install command from rescue mode you should be all set. You might have to specify exactly what disk you want to install grub on (i.e. grub-install /dev/sda1, etc...) if you still experience the black screen.

This is what I used to do a grub fix.

Boot up using RHEL4 disk.

Type: linux rescue

Hit OK.

Hit OK.

Clicked NO (for networking)

Hit OK.

At prompt, type: chroot /mnt/sysimage

At prompt, type: grub

At prompt, type: find /boot/grub/stage1 or find /grub/stage1

At prompt, type: root (results or previous step)

example: root (hd0,0)

At prompt, type: setup (hd0)

Note: use results from above, I used what mine was as in the example.

At prompt, type: quit

At prompt, type: exit

At prompt, type: exit

Machine will reboot and grub should be fixed. Make sure you remove disk during reboot.

Hope this is helpful.

I will make it more clear for the Gurus and helpers

I installed Red Hat Linux

I have partitions like

/dev/sda1 /boot
/dev/sda2 /root
/dev/sda3 swap


I booted my system with rescue mode

chroot /mnt/sysimage/

fdisk /dev/sda

I delted the boot partition (for my lab purpose)

I made it again the boot partition on /dev/sda1

I again rebooted my system with rescue cd

chroot /mnt/sysimage/

df

and I get the following result

/dev/sda2 /

/dev/sda1 /boot

/dev/sda5 /home

now I want to install the grub next steps please.....

thanks
shahz

Here's a good source!

http://www.gnu.org/software/grub/manual/grub.html

Well again after some googling I rebooted my system with rescue mode.

and gave the command

grub-install /dev/sda

type grub

grub> find /grub/stage1

(hd0,0)

setup (hd0,0)

checking if "/boot/grub/stage1" exists .... no
checking if "/grub/stage1" exists .... yes
checking if "/grub/stage2" exists .... yes
checking if "/grub/e2fs_stage1_5" exists ... yes
Running "embed /grub/e2fs_stage1_5 (hd,0)" .. failed (this is not fatal)
running "embed /grub/e2fs_stage1_5 (hd0,0) ... failed (this is not fatal)

running "install /grub/stage1 (hd0,0) /grub/stage2 p /grub/grub.conf" ... succeeded

done.

grub> reboot


after rebooting my system I get the again the prompt for grub

grub>

and now I am lost what to do and what I am missing.

thanks

At the grub prompt try
root (hd0,0)
setup (hd0)

I see that PART of what you did involves the use of "setup" in the GRUB shell. That is the only method I ever use---further, you would not use that AND grub-install. It's one or the other.

To install GRUB, you have to specify where its files are. GRUB files are in /boot/grub, but you have to specify which partition.

Suppose I have the GRUB files---eg the config file, menu.lst---in sda3. ((hd0,2) in GRUB's syntax) And I want GRUB installed in the MBR of sda (hd0). The commands are:

grub (starts the GRUB shell)
root (hd0,2)
setup (hd0)

See also the "booting" link below--it includes a link to the GRUB manual

I don't have any file within the /boot partition because I already delted the partition made it again with fdisk. I rescued the system with a bootable cd.

when I df I get the follwing.

/dev/sda2 /
/dev/sda1 /boot
/dev/sda5 /home

when I used the grub command

grub> At the grub prompt try
root (hd0,0)
setup (hd0)

the output says

checking if "/boot/grub/stage1" exists .... no
checking if " /grub/stage1" exists ..... no

Please keep in mind that I don't have any files within /boot partition because I deleted the parition made it again now want to install grub on it.


thanks

If you have no files in the /boot directory, then you are missing more thatn just GRUB. /boot is where you would find your kernel and various other things.

It seems like re-installing Linux might be the easiest solution.

well thanks brother for advising to reinstall but I want to get everything manually as I told before that I formated the /boot partition my self. if there is a hard way let me know I want to do it.


thanks

You have to install into the /boot directory all of the files normally found there. This includes the Linux kernel, maybe an initrd file, the /grub directory, and a few other things. The only way that I would know what was needed would be to look at a system running RHEL4.

have you tried copying files stage1, stage2 & stage1_5 from /usr/share/grub/i386-pc into /boot/grub/
also cp vmlinuz (kernel binary) from /usr/src/kernel/2.6. . .
(if vmlinuz is not there try compiling new kernel)
create initrd.img file using mkinitrd command.
then do root(hd0,0)
find /boot/grub/stage1 (this should be able to find stage1 file)
setup(hd0)

Note stage1,1_5,2 initrd image, vmlinuz all are needed to boot the system.

can I get the full command for making initrd, I have copied all the files from /usr/share/grub...

mkinitrd /boot/initrd-2.2.5-15.img 2.2.5-15
last argument 2.2.5-15 is the name of linux dir /usr/src/kernels/2.2.5-15/

Also have you got your kernel binary. vmlinux.
you will also need system.map-2.6.22.9 & config-2.6.22.9 file for your kernel.
If you don't have any of these files, then only way is to recompile a new kernel.
you can download latest kernel from www.kernel.org
and then compile using commands
cd /usr/src/kernels/2.6. . .>

make mrproper : will remove any previous installation file
make defconfig : will create makefile with default configuration
make menuconfig: configure any additional options
make modules_install: for installing require modules
make install : will compile kernel using makefile created by make defconfig & menuconfig commands, will also copy vmlinuz kernel, system.map file, config file into /boot dir.

and then create & copy initrd file into /boot.

Your system should boot after this. ! ! !.