If someone a Unix system administrator forgets the root password ?. What will be the consequences ?. Should the OS needs to be reinstalled ??
The 'consequences' will depend on how critical the system is, what the impact will be if any activity that requires the root password gets delayed, and a lot of other things.
Also, retrieving a lost root password differs from system to system. Why don't you tell us what OS you're using, so that someone can help you out with your problem.
That was just a Hypothetical question that crossed my mind. I preferably thought what would happen in Solaris and AIX.
Don't know about AIX. On Solaris, you have to boot from the CD in single user mode, mount the root filesystem and manually edit the shadow file to empty the password field. A reboot would be required.
It's the same in AIX. Boot from CD into mantenance mode and manually edit the /etc/security/passwd file to contain blank password for root. Reboot is therefore required.
How to do in HP-UNIX and SCO?.