Though I haven’t personally been very interested in Btrfs (for a variety of reasons), a lot of people have been pushing it since the Fedora 16, SLES 11, Ubuntu 10.10, and RHEL 6 days. I believe Fedora had it as a default filesystem for the root partition but otherwise Btrfs has not been replacing many Ext4, XFS, or ZFS use-cases in enterprise. Not long ago a rather significant bug had been discovered involving how Btrfs handles “RAID5” and “RAID6” parity calculations. This is extremely risky when it comes time to rebuild a failed disk in an array. It was “fixed” late last year, however, there are apparently still issues with scrub and parity code.
A lot of people refer to Synology devices when justifying the use of Btrfs because Synology does in fact utilize Btrfs on their devices. However, Synology is using the Btrfs filesystem on top of an mdadm RAID – so they are not utilizing Btrfs for RAID5 or RAID6 parity and scrubbing or for any actual hard disk control at all.
A lot of development and effort has gone into Btrfs but to be honest it does not seem like it’ll be perfect anytime soon. Red Hat had Btrfs in “Technology Preview” since the initial release of RHEL 6 but, according to the latest Red Hat deprecation notes, “Red Hat will not be moving
Btrfs to a fully supported feature and it will be removed in a future major release of Red Hat Enterprise Linux.”
Although this is unfortunate, I commend Red Hat for making this decision. Red Hat has positioned themselves as one of the leading enterprise Linux distributions and as such they have to consistently deliver reliable technology which Btrfs is unable to provide at this time. Maybe Red Hat can introduce Btrfs back into the mix in the future, but for now – adieu Btrfs.