The replace operation depends on scrub and makes use of the scrub code. And scrub does not yet support RAID5/6. Therefore ''btrfs replace start'' fails with EINVAL on RAID5/6 filesystems. like linux md raid5 support rescontruct ,btrfs raid5 has plan to support resconstructing? -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html