Grub 2 Boot Order in Debian and Ubuntu servers

Grub2 is entirely different than the older version in terms of configuration and file system hierarchy. In the version 1 of Grub, changing the boot order can be accomplished by a single file editing. But in Grub2 which need to be done in another way, we are going to describe that here.

Here are the steps to follow:

1- To edit the grub file open terminal and type the following command :

    sudo gedit /etc/default/grub

You will got something like this :

GRUB_DEFAULT=0
#GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash”
GRUB_CMDLINE_LINUX=””
# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL=console
# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo’
#GRUB_GFXMODE=640×480
# Uncomment if you don’t want GRUB to pass “root=UUID=xxx” parameter to Linux
#GRUB_DISABLE_LINUX_UUID=true
# Uncomment to disable generation of recovery mode menu entrys
#GRUB_DISABLE_LINUX_RECOVERY=”true”

Now to change the boot order, you need to change the GRUB_DEFAULT Entry, for example you have  windows7 in the 3rd position and you want to set it as default,  edit the entry as below

       GRUB_DEFAULT=3

2- Now update Grub using the command:
 
       sudo update-grub 

Once you run the above command, the grub configuration files will get regenerated and in the file /boot/grub/grub.cfg, you can find an entry as set default = "3"