Backup in the cloud

My WD world edition broke down after 2 years of service due to failing power supply.  I used it to share files with 4 computers in a small office. Now all files were lost (recovery cost me a lot of money). I want to have a copy of my new WD World edition II “in the cloud”, e.g. dropbox or any other suitable service in case the power supply again damages my WD. How can I do that ?

They safest way is to have a backup. which mmeans multiple drives if you have 1 that is not considered a backup

Are you asking if there is a way to have the NAS automatically send a copy of the files to an online backup service?  I don’t know of any that will run on the NAS itself, but you could certainly look around to see which services will give you an app to run on one of the connected computers that will pull files from the NAS and send them to your “cloud.”