btrbk
Tool for creating snapshots and remote backups of btrfs subvolumes
...A declarative configuration describes sources, targets, and retention policies (hourly/daily/weekly/monthly), and btrbk enforces pruning so backup stores don’t grow without bound. The tool supports hierarchical setups—many subvolumes to many destinations—and can throttle, pre/post-hook, and verify operations for reliability. Because it uses native Btrfs primitives, restores are fast and space-efficient, and replicas can be mounted instantly for inspection. Clear logging and dry-run modes make it safe to adopt in production while giving operators visibility into every snapshot and transfer.