By default, the root account password is locked in Ubuntu - Canonical neither supports nor advocates enabling the root account. This means that you cannot login as root directly or use the su command to become the root user. However, since the root account physically exists it is still possible to run programs with root-level privileges.

The Ubuntu system requires you to login as an administrative user to be able to execute commands that only root can execute. However, you can alter the system to allow root to login to perform hours of administration as root. This eliminates the requirement of typing the full path for commands.

Ubuntu root access was blocked by default for GUI. For Enabling This you need to reset password for root.

If you are new to Ubuntu and have been using other distros like Fedora or openSUSE before, then you may find it frustrating that when you issue the "su" command it will result to authentication failure.By default, access to root account password is disabled in Ubuntu for added security measures.

Root is the default name for system administrator in a *NIX system - a super user who can do anything and everything within the operating system. As a result, root login should be used with special care. While working with a root login, we can end up doing a lot of harm to our system as well as the data, accidentally.

One of the biggest security holes you could open on your server is to allow directly logging in as root through ssh, because any cracker can attempt to brute force your root password and potentially get access to your system if they can figure out your password.

The configuration of OpenLDAP got a bit (more) complicated. cn=config is still used, but when installing the packages from the repositories only a skeleton configuration of openldap is installed. You're not asked anymore to provide a password when the package is installed and issuing the "dpkg-reconfigure slapd" only resets openldap to the skeleton configuration.

Not long ago, there were several discussions on UbuntuForums regarding a malicious command which was deliberately posted in the forums in order to make users damage their system if they typed it in a terminal using root privileges. The command is 'sudo rm -rf /' and means 'use root privileges to recursively remove, without asking for permission, the root directory / and its entire contents.

The consensus among new Unix and Linux users seems to be that sudo is more secure than using the root account, because it requires you type your password to perform potentially harmful actions. In reality, a compromised user account, which is no big deal normally, is instantly root in most setups.