In this tutorial you will make exercises modifying configuration files. If you will be performing steps on a production system, have in mind that you will be changing the configuration of all the users - that is probably not a good idea. But, even if you choose the test system to perform the exercises, you will likely want to restore the system to the previous status when you finished the tutorial.

Therefore, before changing any configuration file mentioned in this tutorial, make sure you've made a backup copy of it with the same name, in a backup folder.

When you finished with all the steps, overwrite the changed files with the backup files, and then load the backup files in the database - so your system will return to its default as before you started this tutorial.