OneDrive backups are limited to the last 30 days for undeleted files, and sooner for deleted files. Please see Restoring Files in OneDrive for Business for important information on restore options for changed or deleted OneDrive content.
OneDrive currently offers 1TB of storage space to LETU students, faculty and staff. Use of this space may require up to an equal amount of space on your local drive depending on how you setup your sync options.