Tim Holloway wrote:If you lose the root password, that's a bigger problem, since you need to be logged in as root in order to issue the passwd command in most cases. To recover from that problem, you'd have to shutdown the machine, boot up into single-user mode (which doesn't require a login) and reset the root password. Then reboot into the normal operating runlevel.
On ubuntu, there is no root login by default. All you do you do as user via sudo, and for sudo you need your own password.
However, you're right in the advice to do a (S)uperuser boot. You do it by booting from grub an entry, marked as ... (recovery mode)