Patent attributes
Provided are a storage system and data management method capable of improving the usage efficiency of a storage extent. With this storage system, a first storage apparatus dynamically allocates a storage extent to the first volume and sends data written by the host system in the first volume to the second storage apparatus; a second storage apparatus writes the data sent from the first storage apparatus in a corresponding position in the second volume pair-configured with the first volume and stores as management information the position to which the data from the first storage apparatus in the second volume was written; and the second storage apparatus, during the restoration processing of the first volume, refers to the management information and sends to the first storage apparatus the data in a position to which the data from the first storage apparatus in the second volume was written.
