A method and computer program product for locating data in a system including a plurality of archive units, and answering a query directed to an archive unit. Locating includes broadcasting a query to all the archive units; identifying a set of the archive units that could contain a result for the query; receiving at least one query reply from the archive units; and validating the query reply when the archive unit that sent the query reply is in the set. Answering includes receiving the query; responding to the query when the archive unit could contain a result for the query; and discarding the query without responding when the archive unit could not contain a result for the query.