Lustre capa was introduced since Lustre-2.0, and mainly used for operations authorization and authentication for security. Unfortunately, the original Lustre capa framework had some security holes, and could not work as expectation. And most of later server-side changes ignored the Luster capa process. So there may be probably more security holes related with Lustre capa.

On the other hand, Lustre capa will cause some overhead because of capa calculation. Since it does not work as expectation, we should disable Lustre capa by force until new Lustre capa implemented.