1. A computer implemented method for optimized tracking of cluster-wide connectivity information in a clustering and storage system comprising a plurality of nodes and shared storage, the method comprising the steps of: detecting I/O (“input/output”) errors that result from failed operations in which specific nodes of the cluster attempt to access shared storage; tracking start-times of failed operations that result in I/O errors; comparing start-times of failed operations that result in I/O errors to an update time, the update time comprising a time at which cluster-wide connectivity information was last updated; responsive to results of the comparing, updating the cluster-wide connectivity information in response only to a single I/O error that results from a single failed operation that was initiated after the update time, thereby preventing redundant updates of the cluster-wide connectivity information; and setting the update time to the time at which the cluster-wide connectivity information is updated.