BorgBackup stores encrypted, deduplicated, compressed archives on a disk or a server you control. The tool is aimed at people who will use a terminal. Daily backups stay small because unchanged chunks are not stored again. You can prune old archives and still restore a file from last month.
Borg wants Borg on the far side, usually over SSH. It is not a one-click upload to a random cloud bucket. The passphrase is the archive. Lose it and the backups are gone. A backup you have never restored is a rumor. Do one restore on a boring afternoon before you need it at midnight.
Use it for a home server or a laptop that already has SSH. borgbackup.org
Borg’s passphrase and the repo location belong on paper. Initialize the repo, run one backup, delete a test file, restore it. That drill is the setup. Automated prune rules can delete the only good copy if you set them on a drunk evening. Keep at least a few monthly archives. SSH keys for the backup user should not be the same keys you use to administer the machine that might get hacked.
