Backup

Follow the 3-2-1 rule: three copies of your data, on two different media, with one copy offsite. Tools like Restic, BorgBackup and Duplicati automate encrypted, deduplicated backups. Always test your restores — an untested backup is not a backup.

Backups protect against the things RAID and snapshots can't: accidental deletion, a corrupted database, ransomware, theft and fire. Prioritise your irreplaceable data (photos, documents) and your hard-to-recreate configuration (app databases, Docker compose files), and don't forget to dump databases to a consistent file before copying them. Automate the job on a schedule, encrypt anything that leaves your home, and wire up a success/failure notification so a silent backup failure can't go unnoticed for months. Then prove it works by periodically restoring a few files and, occasionally, a whole service.