btrfs is most certainly not dead.  I actually think it&#x27;s really gaining traction presently.  It only became stable near Ubuntu 14.04 or so, and it takes people awhile (understandably) to warm up to a new filesystem.<p>It&#x27;s great to see ZFS on Linux get a more stable footing.  It&#x27;s an excellent filesystem.  As others have said I think the use case differs slightly from btrfs (though they are very similar in capabilities).<p>ZFS, to my eyes, seems more resilient.  It has more levels of data checksums, The RAIDz model allows for more redundancy, and it just feels like a stronger enterprise offering (meaning stable and built for large systems and disk quantities).<p>btrfs brings many of the ZFS features to Linux in a GPL wrapping.  What it lacks in resiliency, it makes up for with flexibility.  Raid in btrfs, for instance, occurs within data chunks across disks, not at the disk level, meaning mixed disk capacities, and on the fly raid changes. I also appreciate the way it divides namespace across subvolumes while maintaining block awareness within the pool (cp --reflink across subvolumes, snapshots across subvolumes).  It also doesn&#x27;t have the ram requirements of ZFS (which aren&#x27;t much of a data center concern, but are definitely a client level concern for workstations).<p>Either way it&#x27;s a win, both great filesystems for Linux.  With bcache supporting btrfs properly now, I personally don&#x27;t have much of a reason for ZFS now.  Two years ago I would have jumped easily to it.  Your workloads and needs may differ, it&#x27;s great to have choices!