From an operations perspective, ZFS is a god-send. Correct me if I'm wrong, but AFAIK BTRFS lacks any significant quanta of improvement over ZFS, merely a "bet

From an operations perspective, ZFS is a god-send. Correct me if I'm wrong, but AFAIK BTRFS lacks any significant quanta of improvement over ZFS, merely a "better licensed" non-invented-here mostly duplicated effort with a couple refinements that isn't nearly as well thought-out from the experience of ops folk. - Online scrubbing rather than fsck, so there is little/no downtime if the filesystem were interrupted, i.e., datacenter power failure. fsck/raid rebuild of large filesystems can mean lengthy outages for users. - "Always" consistent: Start writing the data of a transaction to unallocated space (or ZIL) and update metadata last. - Greatly configurable block device layer: * RAIDZ, RAIDZ2, RAIDZ3, mirror, concat ... * ZIL (fs journal), L2ARC (cache) can be placed on different media or even combinations of media. - Send & receive snapshots across the network.