What is Grub?
Grub is abbreviaton of “GRand Unified Bootloader”. It is used as a bootloader.
The location of grub is in /boot/grub
taufanlubis@zyrex:~$ cd /boot/grub
taufanlubis@zyrex:/boot/grub$ ls -l
total 224
-rw-r–r– 1 root root 197 2007-07-31 11:29 default
-rw-r–r– 1 root root 15 2007-07-31 11:29 device.map
-rw-r–r– 1 root root 8660 2007-07-31 11:29 e2fs_stage1_5
-rw-r–r– 1 root root 8452 2007-07-31 11:29 fat_stage1_5
-rw-r–r– 1 root root 15 2007-07-31 11:29 installed-version
-rw-r–r– 1 root root 9152 2007-07-31 11:29 jfs_stage1_5
-rw-r–r– 1 root root 4383 2007-09-30 07:37 menu.lst
-rw-r–r– 1 root root 4383 2007-09-30 07:37 menu.lst~
-rw-r–r– 1 root root 5145 2007-09-11 21:42 menu.lst.backup
-rw-r–r– 1 root root 7860 2007-07-31 11:29 minix_stage1_5
-rw-r–r– 1 root root 10132 2007-07-31 11:29 reiserfs_stage1_5
drwxr-xr-x 2 root root 4096 2007-09-21 11:43 splashimages
-rw-r–r– 1 root root 512 2007-07-31 11:29 stage1
-rw-r–r– 1 root root 110132 2007-07-31 11:29 stage2
-rw-r–r– 1 root root 9980 2007-07-31 11:29 xfs_stage1_5
taufanlubis@zyrex:/boot/grub$
If you use more than 1 Operating System, you can set your choice in ‘menu.lst’ file.
Always make a back up before you work with a file system.
taufanlubis@zyrex:/boot/grub$ sudo cp menu.lst menu.lst.backup
Open the menu.lst file.
taufanlubis@zyrex:/boot/grub$ sudo gedit menu.lst
# default number
# Numbering starts from 0, and the entry number 0 is the default if the command is not used.
default 0
## timeout sec
# Set a timeout, in SEC seconds, before automatically booting the default entry
# (normally the first entry defined).
timeout 20
# Pretty colours
color white/blue
title Ubuntu, kernel 2.6.20-15-generic
root (hd0,3)
kernel /boot/vmlinuz-2.6.20-15-generic root=UUID=3bde3b2e-927d-4869-9635-6f7db9d5ed36 ro quiet splash
initrd /boot/initrd.img-2.6.20-15-generic
quiet
savedefault
title Ubuntu, kernel 2.6.20-15-generic (recovery mode)
root (hd0,3)
kernel /boot/vmlinuz-2.6.20-15-generic root=UUID=3bde3b2e-927d-4869-9635-6f7db9d5ed36 ro single
initrd /boot/initrd.img-2.6.20-15-generic
title Ubuntu, memtest86+
root (hd0,3)
kernel /boot/memtest86+.bin
quiet
### END DEBIAN AUTOMAGIC KERNELS LIST
If you upgrade your kernel, you will get another choice of running Ubuntu. Either you want to go with your old kernel or start with a new one. Automatically added to menu.lst
taufanlubis@zyrex:/boot/grub$ sudo apt-get update
taufanlubis@zyrex:/boot/grub$ sudo apt-get upgrade
taufanlubis@zyrex:/boot/grub$ sudo apt-get dist-upgrade
New Kernel menu added after the upgrade proccess has done. You will see it after you reboot your Ubuntu.
Before the menu.lst was:
-
Ubuntu, kernel 2.6.20-15-generic
-
Ubuntu, kernel 2.6.20-15-generic (recovery mode)
-
Ubuntu, memtest86+
My new menu:
-
Ubuntu, kernel 2.6.20-16-generic
-
Ubuntu, kernel 2.6.20-16-generic (recovery mode)
-
Ubuntu, kernel 2.6.20-15-generic
-
Ubuntu, kernel 2.6.20-15-generic (recovery mode)
-
Ubuntu, memtest86+
You have 2 new menus but Ubuntu still keep also the old one.
If you don’t need it any more just remove it.
taufanlubis@zyrex:/boot/grub$ sudo gedit menu.lst
title Ubuntu, kernel 2.6.20-16-generic
root (hd0,0)
kernel /boot/vmlinuz-2.6.20-16-generic root=UUID=3bde3b2e-927d-4869-9635-6f7db9d5ed36 ro quiet splash
initrd /boot/initrd.img-2.6.20-16-generic
quiet
savedefault
title Ubuntu, kernel 2.6.20-16-generic (recovery mode)
root (hd0,0)
kernel /boot/vmlinuz-2.6.20-16-generic root=UUID=3bde3b2e-927d-4869-9635-6f7db9d5ed36 ro single
initrd /boot/initrd.img-2.6.20-16-generic
#——remove this part – START——————————————————————-
title Ubuntu, kernel 2.6.20-15-generic
root (hd0,0)
kernel /boot/vmlinuz-2.6.20-15-generic root=UUID=3bde3b2e-927d-4869-9635-6f7db9d5ed36 ro quiet splash
initrd /boot/initrd.img-2.6.20-15-generic
quiet
savedefault
title Ubuntu, kernel 2.6.20-15-generic (recovery mode)
root (hd0,0)
kernel /boot/vmlinuz-2.6.20-15-generic root=UUID=3bde3b2e-927d-4869-9635-6f7db9d5ed36 ro single
initrd /boot/initrd.img-2.6.20-15-generic
#——remove this part – END——————————————————————-
title Ubuntu, memtest86+
root (hd0,0)
kernel /boot/memtest86+.bin
quiet
Save it. Now you only have the menu for the latest kernel.
