1. A failover method for responding to configuration node failures in a SAN Volume Controller (SVC) cluster, wherein the SVC cluster manages a plurality of storage devices and comprises a plurality of SVCs interconnected via the internet, each SVC acting as a separate node, and at any given time, only one node within the SVC cluster functions as a configuration node to operate external services, the method comprising: making an entry in a storage device event log each time an original configuration node receives storage device events and setting the entry to a negative value indicating a storage device event has not been handled; and setting the entry to a positive value indicating the storage device event has been handled after the original configuration node notifies respective subscribed clients about those of the storage device events the original configuration node receives.