Single User Mode
What is Single User Mode? edit
Single user mode is an alternate method of operation for a computer running a Unix-like operating system. It runs the least possible amount of services and only allows minimal functionality. Usually, this mode is useful for booting a computer whose operating system is damaged or for completing different diagnostic tasks. For the purposes of this lab, utilizing a minimal mode of operation will allow for only a small amount of processes to be running in the background.
How to Activate Single User Mode? edit
Superuser edit
First, a superuser (root user) needs to be activated in order to turn off computer services that will go unused for this experiment. Also, a superuser is need to allow the machine to send large amounts of quick ping signals. Below is a set of instructions on enabling this function:
1. Allow the computer to boot normally into the GUI
2. Load the Terminal
3. Type : sudo passwd root (enable the root account)
4. Create a new password for the root account and confirm it
5. Then enter this line to enable root login: sudo sh -c 'echo "greeter-show-manual-login=true" >> /etc/lightdm/lightdm.conf'
6. Restart the computer: sudo shutdown -h now
7. Now from a new terminal window, one should be able to type su to prompt for the superuser. Then simply type the password for the root user
If complications arise, use the links below for assistance:
https://help.ubuntu.com/community/RootSudo
Single User Set-Up Steps edit
After the superuser function and password has been activated, one may proceed to Single User Mode.
1. Reset computer
2. Upon start-up , hold Shift in order to display the grub boot menu then press e to edit.
3. The top line should read something similar to: Ubuntu, with Linux 2.6.32-22-generic
4. Find this line: linux /boot/vmlinuz-2.6.32-22-generic-pae root=UUID=xxxxxxxx-xxxx-xxxx-xxxxxxxxxxxx ro vga=794 quiet splash
5. Delete this portion of the previous line: ro vga=794 quiet splash
6. Replace this with "single"
7. To complete press: crtl + x
If complications arise, use the link below for assistance:
http://blog.troyastle.com/2010/06/boot-to-single-user-mode-in-ubuntu-1004.html