If your organisation has password aging policy set for your UNIX servers, there is a possibility that the root account may also get locked out due to the existence of an expiry date set in the /etc/shadow file. Once the root account is locked, all jobs (cron, etc) that require root privileges may start to fail. To unlock the root account on a SUN SPARC machine, you will need to:

Ubuntu Linux distribution, by default, disables the root account. To run a command with root privileges, sudo has to be used before the command.

On a typical Fedora installation, you are asked for a root password and you will given an option to create accounts for normal users.

On the other hand, Ubuntu only allows account creation for normal users, root logins are disabled by default.