The Fat-Btree is expected to be used as a parallel directory structure for high performance and highly reliable data intensive systems, such as databases and file systems. Though the Fat-Btree is essentially high performance, it needs to be highly reliable as well. In order to achieve high reliability, we introduce five configuration methods in this paper. We show not only their steady-state and computational availabilities but also cost related comparisons, so as to evaluate the properties of these configurations.