When performing an upgrade to the store, it is highly advisable to perform the back only after the store has been put in maintenance mode. This way, you are certain that no customer data is lost if you have to revert the upgrade to that backup. Do not perform the upgrade before both files and data have been properly backed up on your computer.
The processes described in this chapter will have you transfer files using an FTP client, download SQL data from a web server using online tools, and even delete all your online files and data. Do not attempt this if you do not have a good grasp of these tools and technologies. If you must (for instance, if your store is broken after a failed upgrade), get assistance from a technical friend, and take the time to perform each step completely. If not, you might lose your store forever.
Making your own backup
First, create a folder on your computer, where you will store both your PrestaShop files and data. Put the current date in the folder's name, in order to know exactly from when that backup is.