1. An article of manufacture comprising a computer readable storage medium including program logic for locating data, wherein the program logic when executed causes operations to be performed, the operations comprising: storing mapping information in a metadata store, wherein for each file, the mapping information includes source blocks that indicate locations of source blocks for the file, one or more target blocks that represent one or more copies of the source blocks and provide locations of copies of the source blocks, and a session identifier that identifies a session, wherein the session is a set of copy service relationships that represent a set of data being maintained in a consistent state; providing mapping information for a file to each of multiple client computers coupled to the metadata store; determining that a copy service has copied source blocks to target blocks for the file, wherein the target blocks are a copy of the source blocks for the file; updating the mapping information in the metadata store with locations of the target blocks; and for each of the multiple client computers, determining whether the mapping information for the file should be updated at that client computer to refer to the target blocks based on whether the target blocks are accessed as often as blocks for the file that the client computer is currently accessing; and providing updated mapping information to that client computer in response to determining that the mapping information should be updated to refer to the target blocks based on determining that the blocks for the file that the client computer is currently accessing are being accessed more often than the target blocks.