Patent ID: 8037027
Filing Date: 2011-10-11
Classification: G06F

Abstract:
1. A computer system, comprising: a first storage system coupled to a network; and a second storage system coupled to the first storage system, wherein: the first storage system transmits the journal data including the first differential data item to the second storage system; the second storage system stores the journal data received from the first storage system into the third logical volume; the first storage system deletes at least the first differential data item from the second logical volume; the computer system retains a first management information set that includes information for associating the first logical volume with the third logical volume storing therein the journal data including the first differential data item related to the first logical volume, the journal data related to the first logical volume further includes a second differential data item representing a differential between the data that was stored in the first logical volume at the second time instant and data that was stored in the first logical volume at a third time instant being later than the second time instant; and the first storage system is configured to: transmit the journal data including the created third differential data item to the second storage system.