A method for maintaining data access during failure of a controller in a multiple controller storage subsystem is provided. That assay culture in maintained under appropriate culture conditions and for a time period sufficient to determine the interaction of the microorganism with the AmpC \u03b2-lactamase resistant inhibitor and antibacterial compound, and thereby determine the presence of an AmpC \u03b2-lactamase, wherein a positive test indicates the presence of an AmpC \u03b2-lactamase. In this way, it is possible to achieve an effective securing action even in the event of an unfavorable tolerance pairing, without adversely affecting the sensitive projection itself.