Hello,
Take a look at page #92 of the User manual:
http://www.wdc.com/wdproducts/library/UM/ENG/4779-705103.pdf
It explains about safepoints:
“You can create a complete backup or snapshot of your WD My Cloud device, called a safepoint, and save it to an external location on your home network or an attached USB drive attached to the USB expansion port. Safepoints can be created or run on a schedule you define. They include a record of users, data, and shares on your device; any backups created using WD SmartWare, Apple Time Machine, Windows 7 Backup, or Windows 8 File History, and any associated device configuration details. Creating a safepoint ensures that you can easily recover your data from a specific point in time to a new WD My Cloud device in the unlikely event that your WD My Cloud device fails.”