As a heavy btrfs user backups have always been on my mind. I run a lab with a handful of busy VMs, all using btrfs. I was frustrated that there were no backup solutions (at the time) which leveraged btrfs, so I created snazzer [1] (one day soon it will support ZFS).

You might scoff, but... btrfs send/receive is insanely fast and painless. To mitigate btrfs shenanigans, snapshots end up on non-btrfs filesystems too. I wrote a tool [2] which produces PGP signatures and sha512sums of snapshots to achieve reproducible integrity measurements regardless of FS.

Of course, in the time it took to polish up snazzer a bit for public release, many [3] other [4] cool [5] solutions [6] have materialized [7]... :)

[2] https://github.com/csirac2/snazzer/blob/master/doc/snazzer-m...

[3] https://github.com/masc3d/btrfs-sxbackup

[4] https://github.com/digint/btrbk

[5] https://github.com/jimsalterjrs/sanoid/

[6] https://github.com/lordsutch/btrfs-backup

[7] https://github.com/jf647/btrfs-snap