This is: https://github.com/zfsonlinux/zfs/issues/8306 https://github.com/zfsonlinux/zfs/issues/9193
fixed by: https://github.com/zfsonlinux/zfs/pull/9202 merged at: https://github.com/zfsonlinux/zfs/commit/f335b8ff which should be available in 0.8.2 when it releases. -- Richard
