Back at the RHEL6 launch (working for Red Hat Support) scuttlebutt around Red Hat was that they weren't confident they had the resources to provide full support

Back at the RHEL6 launch (working for Red Hat Support) scuttlebutt around Red Hat was that they weren't confident they had the resources to provide full support for all clients for XFS. At that time it was offered as an add-on for a substantial amount of money. Considering the kind of case work that was being dealt with I don't think this was unreasonable. There was at least 1 time I needed to pull the first few mb of the disk for investigate a corruption issue. I believe the XFS devs (or at least the few I spoke to from the Australian team) all believed XFS was more then ready to replace EXT and should have replaced XFS. I suspect now that EXT4 is showing its age with massive filesystem sizes, that Red Hat is faced with 2 complex file systems. XFS is proven, and reliable. BtrFS is feature rich, evolving, but lacking a proven history with the diversity of systems that Red Hat need to support. Given that, I think going XFS was the expected move by Red Hat... conservative and incremental.