Patent ID: 7844643

Claim:
A computer readable storage medium having computer code executed by a primary controller in communication with a secondary controller to perform operations, the operations comprising: dividing logical volumes managed by the primary storage controller into pages; receiving a write request to the logical volume having modified data; adding a record including the page of the logical volume having the modified data for the logical volume to a primary journal, wherein the primary journal includes records having writes to the pages of the logical volumes, wherein the records are enabled to include multiple versions of modifications to pages of the logical volumes, and wherein the primary journal provides continuous data protection to retain modified data for subsequent read requests to the logical volume; copying records in the primary journal to a secondary journal at the secondary controller, wherein the secondary journal includes the records from the primary journal having pages of the logical volume; receiving a read request to data in the logical volume, wherein multiple versions of the requested data are included in the primary journal; determining the record including one of the versions of the requested data to return to the read request; accessing the determined record of the version of the requested data from the primary journal to return to the read request.