When backing up data, it's best to create more than one backup of your data. If that one backup were to fail, you'll be out of luck on recovering your data and may potentially have to spend money on a service to help recover your data for you. Even then, it may not be possible.
The best practice to backing up your data is following a 3-2-1 backup strategy: three backups, on two different media, and one off-site. The site, dpBestflow.org, is a great resource that shows you how to appropriately back up your data.