b2evolution provides an automated script for creating a backup of your website. This is a good feature that will allow you to create such backups regularly, or at least when you make major changes on your website.
To create a backup of b2evolution, you need to access the administrative dashboard first. Click on the System menu item and then Maintenance.
Select the Backup tab and you will be presented with a list of options that you can choose from for the backup:
When the backup is generated, it will be stored on your account. At the top of the same page, you can see the actual location, where the system will store the backups of your b2evolution website.