Howto:Recover your username and password/Fix Grub 21 Error in Ubuntu

Recovering Your forgotten username and password

If You just installed Ubuntu and forgot what password you selected during the installation process or one of your friend gave you ubuntu computer without giving username and password.This tutorial will help you to recover username and password

1) Turn on your computer, and as soon as you the Press Esc to enter grub message, press the escape key.

2) Select the option that says (recovery mode).

3) Your PC will boot into a shell. Once you get a command prompt, type “passwd username” where the username is your username. If you can’t remember your username, then you can type “ls /home” which should bring it up.

4) Enter a new password when prompted, and again when prompted again Type “shutdown -r now” to reboot your system,

That’s it. You should now be able to login with your new password.

Fix Grub 21 Error in Ubuntu

Problem

I’ve just tried installing Ubuntu but when it restert for the first time, GRUB returns an Error 21. I know this means that it can’t find the grub.conf file, but I don’t know how to fix this. I used Windows XP’s Recovery Console to get back into XP, but I can’t access the GRUB files.

Solution
1. Boot your computer up with Ubuntu CD

2. Open a terminal window or switch to a tty.

3. Go SuperUser (that is, type “sudo -s”). Enter root passwords as necessary.

4. Type “grub”

5. Type “find /boot/grub/stage1″. You’ll get a response like “(hd0,1)”.

Use whatever your computer spits out for the following lines.

6. Type “root (hd0,1)”, or whatever your hard disk + boot partition numbers are for Ubuntu.

7. Type “setup (hd0)”, to install GRUB to MBR, or “setup (hd0,1)” or whatever your hard disk + partition nr is, to install GRUB to a partition.

8. Quit grub by typing “quit”.

9. Reboot and remove the bootable CD.

Note:- In the above procedure hd0,1 is an example it might be different in your case.

Copyright by http://www.ubuntugeek.com

SHOWING SPLASH PICTURE AT GRUB

Originally, Grub menu only a text with dark background. I want to change it in order my menu is good looking with a picture, not just text.

We called this display is "splash" and the picture which used is called "splash picture".

This is a "howto" add and show splash picture.

1. Download and install splash picture
$ sudo apt-get install grub-splashimages
$ sudo aptitude install grub-splashimages
$ sudo dpkg -i grub-splashimages_1.2.3_all.deb
2. If installation is successful, it will create a directory under /boot/grub/splashimages which is consisted with picture in .xpm.gz ekstention
3. Edit menu.lst and add a command
splashimage=/boot/grub/splashimages/biosplash.xpm.gz
And give "#" at command hiddenmenu
4. Restart and we could see our grub menu which have been modified

If we want created picture, we could used gimp or etc which size is 640x480 pixel and colour is 16

Add New OS in GRUB

We assume, we have a machine which alreday installed windows or macintosh. If we have windows and install linux, in OS menu list when we booting, windows already there. But for macintosh, mac not shows in menu list. So to shows mac in menu list we have add it to the menu.lst.

As we know, for primary partition we can make only 4 partition, from hd0 - hd3, and for secondary we can make more than 4.

Assume, our mac is in partition 1 (primary) and linux in partition 2 (primary).

Edit menu list from terminal:
root@hardy:/home/bearisusanto# nano /boot/grub/menu.lst

…………configuration already exist
title Ubuntu 8.04, kernel 2.6.24-16-generic
root (hd0,1)
kernel /boot/vmlinuz-2.6.24-16-generic root=UUID=cadd2657-226c-45cc-90$
initrd /boot/initrd.img-2.6.24-16-generic
quiet

### END DEBIAN AUTOMAGIC KERNELS LIST
…………add in this section for mac OS

title MAC Leopard
root (hd0,0)
makeactive
chainloader +1

Gotcha, when we reboot, the menu will be appear, when we press “esc” button.

Howto reconfigure broken grub

When our grub is broken because of install new windows or our MBR is broken, so we can’t boot on linux.

To normalize grub we can do 2 ways, by using Live CD or we can enter into linux terminal.

For the first time we have to boot by live cd and next we have to do:
1. Open terminal
2. sudo grub
3. grub> find /boot/grub/stage1
(hd0,0)
4. grub> root (hd0,0)
5. grub> setup (hd0)
6. quit
7. Reboot