Tiny Btrfs maintenance daemon

 Btrfsd is a lightweight daemon that takes care of running Btrfs filesystem
 maintenance tasks.
 It can:
 .
  * Check for detected errors and broadcast a warning if any were found,
    or optionally send an email
  * Perform scrub periodically if the system is not on battery
  * Optionally run balancing operations periodically
 .
 The daemon is designed to be run on any system, from a small notebook to a
 large storage server.
 If no Btrfs filesystems are found, the daemon will be inert.
 .
 By default, Btrfsd is called every hour via a systemd timer.