root@vmbox:/home/jon# adduser rowher
Adding user `rowher' ...
Adding new group `rowher' (1002) ...
Adding new user `rowher' (1002) with group `rowher' ...
Creating home directory `/home/rowher' ...
Copying files from `/etc/skel' ...
Enter new UNIX password: 
Retype new UNIX password: 
passwd: password updated successfully
Changing the user information for rowher
Enter the new value, or press ENTER for the default
        Full Name []: 
        Room Number []: 
        Work Phone []: 
        Home Phone []: 
        Other []: 
Is the information correct? [Y/n] 

root@vmbox:/home/jon# adduser rowher sudo
Adding user `rowher' to group `sudo' ...
Adding user rowher to group sudo
Done.

root@vmbox:/home/jon# adduser rohwer libvirtd
adduser: The user `rohwer' does not exist.