Changing Root User Login Method
The simplest method to disable root user login is to change its shell from /bin/bash or /bin/bash (or any other shell that permits user login) to /sbin/nologin , in the /etc/passwd file, which you can open for editing using any of your favorite command line editors as shown. Save the file and close it.
Root Account Status in Ubuntu
Technically, with default installation and without any change, the root account is disabled and locked in Ubuntu.
Modifying Root Password in CentOS
Open a shell prompt and type the passwd command to change root password in CentOS Linux. The actual command to change the password for root on CentOS Linux is sudo passwd root.
Understanding Sudo Command
DESCRIPTION: sudo allows a permitted user to execute a command as the superuser or another user, as specified by the security policy. The invoking user’s real (not effective) user ID is used to determine the user name with which to query the security policy.
Steps to Create a New Sudo User
- Log in to your server as the root user. ssh root@server_ip_address.
- Use the adduser command to add a new user to your system. Be sure to replace username with the user that you want to create.
- Use the usermod command to add the user to the sudo group.
- Test sudo access on new user account.
Linux Commands Overview
The Linux command is a utility of the Linux operating system. All basic and advanced tasks can be done by executing commands. The commands are executed on the Linux terminal. The terminal is a command-line interface to interact with the system, which is similar to the command prompt in the Windows OS.