Asynchronously protecting a synchronously replicated dataset

A recovery storage system, the recovery storage system comprising a computer processor and a computer memory operatively coupled to the computer processor, the computer memory storing computer program instructions that, when executed by the computer processor, cause the recovery storage system to carry out the steps of:

• receiving, by a recovery storage system of a plurality of recovery storage systems, an identifier of a dataset, wherein the recovery storage system is not a member of a plurality of storage systems that synchronously replicate the dataset;
• asynchronously replicating, by the recovery storage system, the dataset, from the plurality of storage systems, wherein the recovery storage system asynchronously receives, from different storage systems of the plurality of storage systems, snapshots of the dataset indicating modifying operations of the dataset that the plurality of storage systems is synchronously replicating;
• detecting, by the recovery storage system, that the dataset on the plurality of storage systems has become unavailable by detecting that the plurality of storage systems is not servicing requests;
• and
• upon detecting that the plurality of storage systems is not servicing requests, synchronously replicating the dataset among the plurality of recovery storage systems, whereby modifying operations directed to the dataset that are completed through any one recovery storage system during synchronous replication are reflected in subsequent access operations to read the dataset from any other recovery storage system of the plurality of recovery storage systems, including servicing requests for the dataset using the dataset on one or more of the plurality of recovery storage systems.