D2L allows users the ability to export their course contents and components. This means that any files that exist in the course content section and the the course structure can be exported in a single .zip file. To learn about this process refer to Export section of the Import/Export Course Contents and Components tutorial.
OIT recommends periodically backing up your course grade book. To learn how to export course grades refer to the Export a Grade Book tutorial.
Once an export is completed, it is good practice to encrypt the grade book file. Consult one of the following tutorials to learn how to encrypt an exported grade book file (depending on your computer's operating system):
If you wish to keep all student Dropbox submissions, D2L has the ability to download user submissions for a single Dropbox folder. The Dropbox tool does not allow for a export of all Dropbox folders and their associated submissions. As such, it is recommended to download submissions for single folders as they are completed, rather than attempting to get all folder submissions at a single point in time, especially with courses with large class sizes. Learn about the process of downloading Dropbox submissions by visiting the Download All Dropbox Folder Submissions tutorial.