I do the same with btrfs. I actually tried bup first, but had a series of problems (see mailing list) and switched to btrfs snapshots. My main disk is also bt

I do the same with btrfs. I actually tried bup first, but had a series of problems (see mailing list) and switched to btrfs snapshots. My main disk is also btrfs so I send incremental snapshots ("btrfs send -p"; faster than rsync and I can keep using the machine without making the backed-up state inconsistent), but the rsync method is fine for other source file systems.