sudo_root - How to run administrative commands
By default, the password for the user "root" (the system administrator)
is locked. This means you cannot login as root or use su. Instead, the
installer will set up sudo to allow the user that is created during
install to run all administrative commands.
This means that in the terminal you can use sudo for commands that
require root privileges. All programs in the menu will use a graphical
sudo to prompt for a password. When sudo asks for a password, it needs
your password, this means that a root password is not needed.
To run a command which requires root privileges in a terminal, simply
prepend sudo in front of it. To get an interactive root shell, use sudo
ALLOWING OTHER USERS TO RUN SUDO
By default, only the user who installed the system is permitted to run
sudo. To add more administrators, i. e. users who can run sudo, you
have to add these users to the group 'admin' by doing one of the
* In a shell, do
sudo adduser username admin
* Use the graphical "Users & Groups" program in the "System settings"
menu to add the new user to the admin group.
BENEFITS OF USING SUDO
The benefits of leaving root disabled by default include the following:
* Users do not have to remember an extra password, which they are
likely to forget.
* The installer is able to ask fewer questions.
* It avoids the "I can do anything" interactive login by default - you
will be prompted for a password before major changes can happen,
which should make you think about the consequences of what you are
* Sudo adds a log entry of the command(s) run (in /var/log/auth.log).
* Every attacker trying to brute-force their way into your box will
know it has an account named root and will try that first. What they
do not know is what the usernames of your other users are.
* Allows easy transfer for admin rights, in a short term or long term
period, by adding and removing users from the admin group, while not
compromising the root account.
* sudo can be set up with a much more fine-grained security policy.
* On systems with more than one administrator using sudo avoids sharing
a password amongst them.
DOWNSIDES OF USING SUDO
Although for desktops the benefits of using sudo are great, there are
possible issues which need to be noted:
* Redirecting the output of commands run with sudo can be confusing at
first. For instance consider
sudo ls > /root/somefile
will not work since it is the shell that tries to write to that file.
You can use
ls | sudo tee /root/somefile
to get the behaviour you want.
* In a lot of office environments the ONLY local user on a system is
root. All other users are imported using NSS techniques such as
nss-ldap. To setup a workstation, or fix it, in the case of a network
failure where nss-ldap is broken, root is required. This tends to
leave the system unusable. An extra local user, or an enabled root
password is needed here.
GOING BACK TO A TRADITIONAL ROOT ACCOUNT
This is not recommended!
To enable the root account (i.e. set a password) use:
sudo passwd root
Afterwards, edit the sudo configuration with sudo visudo and comment
out the line
%admin ALL=(ALL) ALL
to disable sudo access to members of the admin group.
February 8, 2006 sudo_root(8)