• http://git.kernel.org/cgit/linux/kernel/git/tor valds/linux.git/commit/fs/btrfs?id=4204617d142c 0887e45fda2562cb5c58097b918e • Btrfs is highly experimental, and THE DISK FORMAT IS NOT YET FINALIZED. You should say N here unless you are interested in testing Btrfs with non-critical data.