A method, system and computer program product for preserving data in a storage subsystem having dual cache and dual nonvolatile storage (NVS) through a failover from a failed cluster to a surviving cluster, the surviving cluster undergoing a rebooting process, is provided. A memory preserved indicator associated with a cache of the surviving cluster is detected. The memory preserved indicator designates marked tracks having an image in an NVS of the failed cluster to be preserved through the rebooting process. A counter in a data structure of the surviving cache is incremented. If a value of the counter exceeds a predetermined value, a cache memory is initialized, and the marked tracks are removed from the cache to prevent an instance of repetitive reboots caused by a corrupted structure in the cache memory.