The first rule of sysadmin: Have a regular schedule for testing your offsite backups of all your systems. After that, as others have noted, create and review a

The first rule of sysadmin: Have a regular schedule for testing your offsite backups of all your systems. After that, as others have noted, create and review a threat model and use that to guide your hardening based on official guides: https://www.debian.org/doc/manuals/securing-debian-manual/ https://www.debian.org/doc/manuals/securing-debian-manual/ and here's a readable introduction to the NIST STIGs: https://cybergladius.com/nist-server-hardening-best-practices/ https://cybergladius.com/nist-server-hardening-best-practice...