View source for Change Boot Menu options from Grub Bootloader

[[Category:Linux]][[Cagtegory:Ubuntu]]
== What is the Grub Bootloader? ==

Grub stands for ('''''GR'''''and '''U'''nified '''B'''ootloader)

The '''Grub bootloader''' is a package that is used to boot various operating systems via a menu upon computer system boot-up.
The bootloader menu file usually resides (or resided) in the '''/boot/grub/menu.lst''' file.


== How the Grub Bootloader Works ==

Generally when most Linux systems are installed, the Grub bootloader program is installed. After Linux installation and computer reboot, the Grub bootloader menu should appear offering the user with a selection of operating systems to boot. The concept is similar to the '''boot.ini''' file that '''NTLDR''' (the boot loader for Windows OS) uses to supply a menu selection for a multiple-boot system.


When the computer system starts, the computer's BIOS locates and runs the bootstrap program on the MBR (Master Boot Record). A series of programs (of Grub) are run provide the user with a selection of operating system to boot. For example, the user can select a version of Linux to load the Linux Kernel, or the user can select another operating system (like Windows) to load in the boot-loader (eg. NTLDR). This process of loading boot loaders for other non-Linux operating systems is referred to as '''chainloading'''.


== Why Edit the Grub Bootloader?  ==

There are numerous reasons to edit the Grub bootloader:

* Change the order of bootable operating systems in the menu list
* Change the DEFAULT bootable operating system (eg. from timeout or "count-down")
* Change the DEFAULT count-down (timeout) value
* Change the appearance (color) of the bootloader menu
* Assign a boot password
* Add additional options to the kernel upon loading Linux Kernel


'''NOTE: Many people complain that installing Linux causes Linux to be the DEFAULT operating system from a boot-loader list in Grub.'''<br />
'''But the user can simply <u>edit</u> bootloader menu file to make their preferred operating system the DEFAULT.'''


==Editing the Grub Bootloader ("'''/boot/grub/menu.lst'''" file exists) ==

Let's assume that we have just installed Linux on our machine, and we want to edit the Grub Bootloader to set MS Windows as the DEFAULT operating system.<br /><br />
!! '''NOTE:''' You should first make a <u>backup copy</u> of the bootloader file prior to making any editing changes. We will show you this in the step below !!


<u>'''STEPS'''</u>:


# Boot up into your <u>Linux system</u>.<br /><br />
# Open a command prompt (called a ''Linux shell'') by selecting '''APPLICATIONS''' -> '''ACCESSORIES''' -> '''TERMINAL'''<br /><br />
# In the terminal, issue the command:  '''sudo su'''   (this will give administrator priviledges - assuming your have these priviledges, enter your account password)<br /><br />
# Issue the command: '''cp   &nbsp;&nbsp;/boot/grub/menu.lst   &nbsp;&nbsp;/boot/grub/menu.bk'''     (just making a backup copy...)<br /><br />
# Issue the command: '''gedit   &nbsp;&nbsp;/boot/grub/menu.lst'''   (this opens the file in gedit application to allow you to make changes)<br /><br />
# Under Comments '''## End Default Options ##''' lists the linux Kernel versions (in groupings labelled '''title''', '''uuid''', '''kernel''' and '''initrd''') that will boot up.<br/> The first grouping at the top of that list will be the DEFAULT operating system.<br /><br />
# Farther below should list '''non-linux OS''' choices. Usually you can identify them because in the grouping will contain the keyword "'''chainloader'''"<br /><br />
# Copy and paste the non-linux (eg. Windows) groupings labelled '''title''', '''rootnoverify''', '''savedefault''', '''makeactive''', and '''chainloader''' immediately <u>ABOVE</u> the DEFAULT <u>Linux</u> grouping<br /><br />
# Save and exit the file.<br /><br />
# Test-out by rebooting your machine to load into your DEFAULT (Windows) OS, and then reboot to load into your Linux menu item.


==Editing the Grub Bootloader ("'''/boot/grub/menu.lst'''" file does <u>NOT</u> exist) ==

I discovered when I installed Mythbuntu 9.10 from a fresh install that the /boot/grub/menu.lst file did NOT exist!
I suspect there was a change in procedure...


Below are steps to edit the Grub Bootloader if the menu.lst file does NOT exist...


<u>'''STEPS'''</u>:


# Boot up into your <u>Linux system</u>.<br /><br />
# Open a command prompt (called a ''Linux shell'') by selecting '''APPLICATIONS''' -> '''ACCESSORIES''' -> '''TERMINAL'''<br /><br />
# In the terminal, issue the command:  '''sudo su'''   (this will give administrator priviledges - assuming your have these priviledges, enter your account password)<br /><br />
# Issue the command: '''cp   &nbsp;&nbsp;/etc/default/grub   &nbsp;&nbsp;/etc/default/grub.bk'''     (just making a backup copy...)<br /><br />
# Issue the command: '''ls &nbsp;&nbsp;/etc/grub.d'''<br /><br />You should see a number, followed by the name of the Windows OS. '''Take note of that number'''.<br /><br />
# Issue the command: '''gedit   &nbsp;&nbsp;/etc/default/grub'''   (this opens the file in gedit application to allow you to make changes)<br /><br />
# Change the option '''GRUB_DEFAULT=0''' to correspond to that number for your Windows OS boot loader.<br />For example, ''GRUB_DEFAULT=3'' <br /><br />
# Save and exit the file.<br /><br />
# Run the command: '''update-grub'''<br /><br />
# Test-out by rebooting your machine to load into your DEFAULT (Windows) OS, and then reboot to load into your Linux menu item.<br /><br />

'''This Author's opinion:''' I suspect that this new method was designed to make things simpler, but I prefer (or at least I got used to) editing menu.lst file...


== The "Dreaded" Growing Grub Bootloader Menu List! ==

Since Ubuntu Linux distributes a major release every six months, and new kernel distributions can be made available between major releases, the Grub bootloader menu list can grow LARGE.

I have seen my Bootloader menu grow to such an extent, that I have to scroll down several screens to boot a non-Linux OS! Therefore, occasionally, you can edit the Grub bootloader to shorten that list.


Just two things to remember <u>prior</u> to editing:


* Create a backup prior to editing.
* Don't remove the CURRENT DEFAULT Operating System to boot!


Hope this helps :)

Murray Saul