Patent ID: 8037368

Claim:
A redundant storage system having a self-monitoring function, the redundant storage system comprising: a plurality of controllers, each performing the self-monitoring function via a self-monitoring device, wherein the self-monitoring device comprises a self-monitoring operating circuit and a watchdog unit; and at least one common transmission interconnect connected to the controllers; wherein, in one of the controllers, when the one controller is failed, a first self-monitoring device generates a first output signal, and said one controller is shut down in response to the first output signal; wherein the self-monitoring operating circuit periodically sends a confirmation signal to the watchdog unit in order to determine whether or not the one controller is failed, and the watchdog unit recounts time if the watchdog unit receives the confirmation signal within a predetermined period of time; and wherein the watchdog unit comprises: a confirmation signal detecting unit connected to the self-monitoring operating circuit for receiving the confirmation signal and for generating a clear signal in response to the confirmation signal; an output signal generating unit for generating the first output signal when said watchdog unit of said one controller does not receive the confirmation signal sent from said self-monitoring operating circuit over the predetermined period of time; and a counter connected to the confirmation signal detecting unit and the output signal generating unit for counting the predetermined period of time.