Grub - Revision history

Jon787 at 05:27, 25 November 2009

2009-11-25T05:27:31Z

← Older revision		Revision as of 05:27, 25 November 2009
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	There are two methods two reinstall grub. These can be used to fix the dreaded <code>GRUB error 15</code> on boot. These will not help you if you simply get dropped to the grub shell instead of seeing a menu.		There are two methods two reinstall grub. These can be used to fix the dreaded <code>GRUB error 15</code> on boot. These will not help you if you simply get dropped to the grub shell instead of seeing a menu.

	Note: the grub bootloader is always 32-bit code, so you don't have to ensure you get an amd64 livecd just because you have an amd64 system.

	== Method 1 ==		== Method 1 ==

	This method will install the grub bootloader from the live cd onto your hard drive.		This method will install the grub bootloader from the live cd onto your hard drive.

			NOTE: You can use a 32-bit live cd with a 64-bit installation of linux.

	1. Acquire a live cd with grub on it.		1. Acquire a live cd with grub on it.
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	cd /pub; more beer		cd /pub; more beer

	9. Run the grub installation command (If this command isn't found then ~~see~~ method 2)		9. Run the grub installation command (If this command isn't found then switch to Method 2, you can start with step 7. See the NOTE at the start of method 2 though)
	grub-install --root-directory=/target /dev/sda		grub-install --root-directory=/target /dev/sda

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	This method creates a fakeroot containing your actual installed linux distro and then installs the grub from that to your hard disk.		This method creates a fakeroot containing your actual installed linux distro and then installs the grub from that to your hard disk.

			NOTE: If your linux install is 64-bit, then you <b>must</b> use a 64-bit live cd!

	1. Acquire a live cd		1. Acquire a live cd

Jon787 at 05:18, 25 November 2009

2009-11-25T05:18:38Z

← Older revision		Revision as of 05:18, 25 November 2009
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			There are two methods two reinstall grub. These can be used to fix the dreaded <code>GRUB error 15</code> on boot. These will not help you if you simply get dropped to the grub shell instead of seeing a menu.
	There are two methods two reinstall grub:

	Note: the grub bootloader is always 32-bit code, so you don't have to ensure you get an amd64 livecd just because you have an amd64 system.		Note: the grub bootloader is always 32-bit code, so you don't have to ensure you get an amd64 livecd just because you have an amd64 system.
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	cd /pub; more beer		cd /pub; more beer

	0. Run the grub installation command (If this command isn't found then see method 2)		9. Run the grub installation command (If this command isn't found then see method 2)
	grub-install --root-directory=/target /dev/sda		grub-install --root-directory=/target /dev/sda

Jon787: New page: There are two methods two reinstall grub: Note: the grub bootloader is always 32-bit code, so you don't have to ensure you get an amd64 livecd just because you have an amd64 system. == M...

2009-11-25T05:14:57Z

New page: There are two methods two reinstall grub: Note: the grub bootloader is always 32-bit code, so you don't have to ensure you get an amd64 livecd just because you have an amd64 system. == M...

New page

There are two methods two reinstall grub:

Note: the grub bootloader is always 32-bit code, so you don't have to ensure you get an amd64 livecd just because you have an amd64 system.

== Method 1 ==

This method will install the grub bootloader from the live cd onto your hard drive.

1. Acquire a live cd with grub on it.

2. Boot the live cd.

3. Open a terminal

4. Become root (from now on being root is implied for this guide)
sudo -i

5. Create a temporary working area. I like to use /target, its a debian habit.
mkdir /target

6. Mount your root partition. I'll be assuming its the first partition on sda for my examples
mount /dev/sda1 /target

7. If you have a seperate boot partition (the 2nd partition on sda in my example) then you have to mount that as well. Skip this step otherwise.
mount /dev/sda2 /target/boot

8. I don't want to catch anyone not drinking
cd /pub; more beer

0. Run the grub installation command (If this command isn't found then see method 2)
grub-install --root-directory=/target /dev/sda

10. Unmount your boot partition if you had one
umount /target/boot

11. Unmount your root partition
umount /target

12. Reboot (make sure to remove the livecd at some point)

== Method 2 ==

This method creates a fakeroot containing your actual installed linux distro and then installs the grub from that to your hard disk.

1. Acquire a live cd

2. Boot the live cd.

3. Open a terminal

4. Become root (from now on being root is implied for this guide)
sudo -i

5. Create a temporary working area. I like to use /target, its a debian habit.
mkdir /target

6. Mount your root partition. I'll be assuming its the first partition on sda for my examples
mount /dev/sda1 /target

7. If you have other partitions you'll want to mount them now at the appropriate places under /target. You must have atleast /usr and /boot mounted if they are seperate partitions:
mount /dev/sda2 /target/boot
mount /dev/sda3 /target/usr

8. Now we need to mount some extra virtual partitions
mount -o bind /dev /target/dev
mount -o bind /dev/shm /target/dev/shm
mount -o bind /dev/pts /target/dev/pts
mount -o bind /sys /target/sys
mount -o bind /proc /target/proc
mount -o bind /proc/bus/usb /target/proc/bus/usb

9. Enter the fakeroot
chroot /target

10. Run the grub installation command (If this command isn't found then see method 2)
grub-install /dev/sda

11. Exit the fakeroot
exit

12. Unmount the virtual partitions
umount /target/proc/bus/usb
umount /target/proc
umount /target/sys
umount /target/dev/pts
umount /target/dev/shm
umount /target/dev

13. Unmount your other partitions if you have them
umount /target/usb
umount /target/boot

14. Unmount your root partition
umount /target

15. Reboot (make sure to remove the livecd at some point)