Red Hat has had this project for a while to give XFS (a traditional journaled filesystem) the features of "3rd generation" filesystems like ZFS or btrfs (i.e. c

Red Hat has had this project for a while to give XFS (a traditional journaled filesystem) the features of "3rd generation" filesystems like ZFS or btrfs (i.e. checksums, snapshots and deduplication). That's mostly glued together using LVM and new LVM addons like VDO, but also new work in XFS itself like reflinks, metadata checksums etc. To me it seems like Red Hat lost faith in btrfs in the RHEL 7 time frame and that's why they dropped it from Tech Preview status.