Patent ID: 7599951

Claim:
A computer-implemented method of handling writing new data, comprising: creating a journal entry that points to a first storage location containing old data to be replaced by the new data, wherein the journal entry is maintained after writing the new data; allocating new storage space having a second storage location; and writing the new data to the new storage space at the second storage location, wherein the old data is maintained in the first storage location after writing the new data to the new storage space at the second storage location, wherein the journal entry pointing to the first storage location containing the old data provides a previous state corresponding to the old data, wherein the previous state is accessible after writing the new data, wherein the new data and subsequent new data are kept from overwriting the old data corresponding to the journal entry, wherein the new storage space is provided by at least one storage device, and wherein allocating new storage space includes remapping a switch coupled to the at least one storage device.