How to disable recovery mode/single user mode?

I am making installation for school computers. I would like to remove single user mode booting, which can make student root user. How to permanently remove single user / recovery mode from GRUB? I am also concerned with updating kernel (update-grub)

I DO need GRUB for booting into Windows installation.


Solution 1:

  1. Open a terminal with Ctrl+Alt+T shortcut and type this command and then hit Enter.

    gksu gedit /etc/default/grub
    
  2. The above command will open GRUB default file in gedit text editor. Search for a section like this one:

    # Uncomment to disable generation of recovery mode menu entries
    #GRUB_DISABLE_RECOVERY="true"
    
  3. Remove the # mark from the line #GRUB_DISABLE_RECOVERY="true". The changed section should look like this:

    # Uncomment to disable generation of recovery mode menu entries
    GRUB_DISABLE_RECOVERY="true"
    

    Save the file by pressing Ctrl+S, then exit gedit.

  4. Then again going to the terminal, execute the below command:

    sudo update-grub
    

Restart to see that the recovery option has gone.

Solution 2:

Its important to remember as january mentioned that once someone has access to the machine it becomes very hard to completely secure it.

Information about grub2 password protection and password protecting recovery mode can be found here https://askubuntu.com/a/78051/71679

Some additional information that may be of interest in your case would be to look at the Bastille hardening program https://help.ubuntu.com/community/BastilleLinux and here http://www.bastille-unix.org/Reporting/assessment-report.html

Also you may be interested in the edubuntu version that includes LTSP. In an LTSP thin client environment, all software for workstations originates on the LTSP server. Whether you are repurposing old desktop PCs or deploying new thin client devices. LTSP allows you to maintain your entire computer network from a single point of control; from the operating system image on the thin clients through user authentication and file storage. By reducing your software footprint with LTSP, maintenance and support obligations are reduced when compared to traditional desktop PC computing solutions.

edubuntu http://www.edubuntu.org/ and more information about LTSP http://www.ltsp.org