FTP is a way for people to upload content to a network attached storage device, server or computer/mobile device. The My Cloud Dashboard allows one to enable FTP on the Settings > Network page.
The key is to find out which folder is taking up the most space and then figure why it is taking up so much space. The Dashboard may not give one the granular details to figure out which specific folder is taking up so much space. One can review each Share through the Dashboard > Share page to see which Share is using the largest amount of data storage.
People who use WD Sync have reported the program ■■■■■ up a lot of space on the My Cloud due to how it allows one to restore a deleted file. If one is running WD Sync on multple computers and is Syncing a large amount of data that may account for the My Cloud getting filled up.
https://community.wd.com/t/wdtemp-folder/145676
If you have not already done so you may want to read through the My Cloud User Manual at the following link to familiarize yourself with the device and its features/settings.
http://www.wdc.com/wdproducts/library/?id=439&type=25
