My First Experience with GRUB

Hi Friends. So, here I am again there with my experience and I think my GRUB experience (till now) would be an amazing topic

So let us start from the start 🙂

What is GRUB ?

GRUB is a boot loader designed to boot a wide range of operating systems from a wide range of file systems. (copied :-p)

GRUB creates and manages the screen containing list of OS available in the system that we see while booting process. (in simple language)

Why I felt the need to change GRUB boot loader?

1. To make the boot menu visible

When Xen hypervisor is installed in Ubuntu 14.04 or higher versions it automatically changes the GRUB to boot XEN and hides the OS list menu on boot. So, if you want the menu to appear on boot then follow the steps :

Open /etc/default/grub and change GRUB_HIDDEN_TIMEOUT

GRUB_HIDDEN_TIMEOUT=-1

And then update your grub by running the following command

update-grub2

and on next boot you will see the boot menu 🙂

2. To pass boot parameters to Xen

I have to change the scheduler in Xen to credit2 scheduler and for that I have to pass the parameters to Xen kernel.

Open /etc/default/grub and append the following line at the end

GRUB_CMDLINE_XEN=”sched=credit2″

And update your grub

update-grub2

So to pass parameters to Xen Kernel you just have to insert parameters between ” ”

Example

GRUB_CMDLINE_XEN=”sched=credit2  cpuinfo=1″

grub

But this is not an end I will keep updating about GRUB. 🙂

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s