Explanation: chattr is a command that allows a user to set certain attributes on a file residing on a Linux filesystem. A “+i” flag adds an immutable attribute to the file. When this is enabled, even a root user cannot change the file. Similarly, a “-i” flag subtracts the specific attribute from the file.
If you have a folder of files that you want to lock up, you can also add the “+R” flag. For example: Note: Only the superuser or a process pessessing the CAP_LINUX_IMMUTABLE capability can set or clear this attribute.