I've been a big proponent of ZFS, but recently btrfs has been making a lot of good progress with features. Most interesting to me is the ability to rebalance a

I've been a big proponent of ZFS, but recently btrfs has been making a lot of good progress with features. Most interesting to me is the ability to rebalance and switch redundancy levels. I have 20TB btrfs array in production as a backup target for a couple months now and it's been doing OK. I've even switched it from raid6 to raid10 and back. There's still a lot of rough edges though, which is why I'm only using it as a backup.