btrbk is a backup tool for btrfs subvolumes, taking advantage of btrfs
specific capabilities to create atomic snapshots and transfer them
incrementally to your backup locations.

The source and target locations are specified in a config file, which
allows to easily configure simple scenarios like "laptop with locally
attached backup disks", as well as more complex ones, e.g. "server
receiving backups from several hosts via ssh, with different retention
policy".

Key Features:

*   Atomic snapshots
*   Incremental backups
*   Configurable retention policy
*   Backups to multiple destinations
*   Transfer via ssh
*   Resume of backups (if backup target was not reachable for a while)
*   Encrypted backups to non-btrfs destinations
*   Wildcard subvolumes (useful for docker and lxc containers)
*   Transaction log
*   Comprehensive list and statistics output
*   Resolve and trace btrfs parent-child and received-from relationships
*   Display file changes between two backups

btrbk is designed to run as a cron job for triggering periodic snapshots
and backups, as well as from the command line (e.g. for instantly
creating additional snapshots).
