Ubuntu
grub2 package

confusion about the boot loader

Asked by Jerry Story

I have:
Windows Vista on sda1
Ubuntu 9.10 on sdb1
Ubuntu 9.10 on sdb3

9.10 on sdb1 is an upgrade.
9.10 on sdb3 is an install from a CD.

I installed 9.10 on sdb3 only to restore the boot loader, which wasn't working. This got the boot loader back.

The boot loader shows:
Windows Vista -- This works.
9.10 on sdb1 -- This works.

There are several instances of 9.10 on sdb1, but no 9.10 on sdb3 even tho I installed it on sdb3.

Questions:

1. Where is the boot loader? Is it on sda1? Is it on sdb1? Is it on sdb3?

2. Why does the boot loader not show 9.10 on sdb3? (Not that it matters much, but I want to understand things.)

3. Why are there several instances of 9.10 on sdb1, with different versions of the linux kernel?

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Nandan Vaidya (gotunandan) said : 		#1

>>> 1. Where is the boot loader? Is it on sda1? Is it on sdb1? Is it on sdb3?

The bootloader by default resides in the MBR (as long as you did not change the settings in the installer ?)
which is /dev/sda. (or maybe /dev/sdb since you say you have two physical hard disks ?) This will then load the stage2 boot loader which should be present on /dev/sdb3 which is the partition for your most recent installation of ubuntu 9.10
One way to solve this problem is to goto /boot/grub on both the partitions on which you have ubuntu installed.
Since your ubuntu on /dev/sdb1 is an upgrade you should still have grub (or grub-legacy as its now called). It shows up as grub 0.98 or 0.97, one of the two, i dont recollect !
Your fresh installation of ubuntu 9.10 will have grub2 (it shows up as grub 1.97 above the bootloader menu).

>>> 2. Why does the boot loader not show 9.10 on sdb3?

Not really sure, it does happen sometimes that the $ update-grub command fails to detect certain entries
This link has lots of good infoon Grub2 and few links to other resources as well
https://help.ubuntu.com/community/Grub2

>>> 3. Why are there several instances of 9.10 on sdb1, with different versions of the linux kernel?

This happens because update-grub runs everytime you download and install a newer version of the kernel. This detects more than one kernel image within your /boot directory and adds all of them to the grub2 menu.
For safety reasons, by default older kernel versions are never removed even after installing newer ones

Hope this helps,
Feel free to ask any questions :)

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