Another possibility if a dedicated backup tool might be an option: I'd like to recommend the restic project. I've been using it for more than a year now on multiple FreeBSD servers and I'm really happy with it. It's an encrypted backup, files are split into chunks and compressed, deduplication of the chunks is included, it's very reliable and (after the first initial backup) incremental backups are incredibly fast. Restore also works flawlessly, as I've had to test on multiple occasions.