It's important to keep backups of any data which you upload to Viaduct (or, indeed, any hosting provider). We've just added a new Database Export feature which allows you to download a dump of your MySQL & Postgres databases.
Not only can you download an export, you can also configure your application to upload your export to Amazon S3 or your own external SFTP server.
To get started, just head over to the Info page for any MySQL or Postgres database and click the Export Database button from the right menu. You will then be prompted to choose how you would like your exported data delivered.
At the moment it is not possible to automate this but we are looking at add a scheduled export feature soon.