# Baustein - Backup ## How to set up 3-2-1 backup Recommended by no less an authority than the Department of Homeland Security’s Computer Emergency Readiness Team, a [3-2-1 backup formula](https://www.cisa.gov/uscert/sites/default/files/publications/data_backup_options.pdf) protects against data loss. Here are the basics: 1. Keep at least **3** copies of any important file: 1 primary and 2 backups 2. Keep files on **2** different media types (for example, computer hard disk plus external hard drive, solid state drive, or cloud service) 3. Store **1** copy off-site (perhaps your office or a cloud service) *** References: 1. [🦅 - ]() Related: - [[Baustein Software Stack]] - [[]] Tags: