Permit root login ubuntu

Procedure

1. To enable remote root login, enter the following command:

   /etc/ssh/sshd_config:
   	PermitRootLogin yes #enabled

2. To disable remote root login, enter the following command:

   /etc/ssh/sshd_config:
   	PermitRootLogin no #disabled

Results

For the change to take effect, the ssh daemon must be restarted:

/etc/init.d/sshd restart 

https://www.ibm.com/docs/en/db2/11.1?topic=installation-enable-disable-remote-root-login