1. A computer-implemented data storage system comprising: host mapping logic configured to map responsibility for storing a plurality of data sets to individual ones of a plurality of hosts which cooperate to implement a data storage system; data set replication logic configured to write a first plurality of copies of a data set at a first subset of the plurality of hosts, the first subset of the plurality of hosts being selected to write the data set; data set retrieval logic configured to be responsive to a request to provide a single copy of the data set by reading a second plurality of copies of the data set at a second subset of the plurality of hosts, the second subset of the plurality of hosts having at least one host not in common with the first subset of the plurality of hosts; and an evaluation component configured to provide a single copy of the data set by reading the second plurality of copies of the data set and reconciling the read data using data versioning information; wherein the evaluation component is configured to be invoked after the second plurality of copies of the data set is read.