1. Logged to instance with ubuntu user
2. Backup shadow file and set password for root with below command # cp -p /etc/shadow /etc/shadow_backup # passwd (Here you set a password for root)
3. Backup sshd_config file # cp -p /etc/ssh/sshd_config /etc/ssh/sshd_config_backup
4. Enabled root login and enabled password-based authentication # vi /etc/ssh/sshd_config
5. Modified below entries and saved file PermitRootLogin yes PasswordAuthentication yes
6. Restart sshd service # service sshd restart
