To ensure SELinux is running in Enforcing mode, you need to follow these steps: First, check the current mode of SELinux using the command 'getenforce'. If the mode is not 'Enforcing', you should edit the SELinux configuration file to make the change permanent. Open the file '/etc/selinux/config' with a text editor, such as 'vi' or 'vim'. Within this file, find the line that starts with 'SELINUX=' and change its value to 'enforcing'. The line should read 'SELINUX=enforcing'. Save the file and exit the text editor. Finally, reboot the system to apply the changes. This will ensure that SELinux runs in Enforcing mode persistently across reboots.