Resilient mediation between storage systems replicating a dataset, including: receiving, by a mediation service from one or more storage systems that synchronously replicate a dataset, a request to resolve which storage system continues to service a dataset after the request; and sending, from the mediation service to at least one of the storage systems, a positive mediation result, wherein: the storage systems that received the positive mediation result continue to process data storage requests directed to the dataset, and the storage systems that did not receive a positive mediation result from the mediation service do not continue to process data storage requests directed to the dataset.