Recently I faced a huge issues in my production environment ,where
ppl try to login as root to system which made system more unstable(Yes I know
its in mess- super democracy server). As you know Ubuntu came with ‘Sudo’
concept which gives all the privilege’s that you want in systems. There for don
not allow root user in your system especially in production. More details can
be found in : https://help.ubuntu.com/community/RootSudo
Two steps to block any root logins :
1.
Disable Root user :
sudo passwd -dl root
2. Disable root login in ssh config:
vim
/etc/ssh/sshd_config
PermitRootLogin
no
And
restart sshd -- > /etc/init.d/sshd restart
BTWAY: I was able to recover lost root password
from a linux machine. Will update on that in future release .