Check your /root/.bashrc file for these lines if [ -f /etc/bash_completion ]; then . /etc/bash_completion fi If they do not exist add them to the end of the file using your favorite text editor.
Here is what the above code is Doing:
1. The first line is a comment.
2. The second line is a conditional statement. If the file /etc/bash_completion exists, then the third line is executed.
3. The third line is a command that will source the file /etc/bash_completion.