Patent ID: 7325158

Claim:
A method for operating a data processing system, the method comprising: assigning two or more active data processing units to a redundancy data processing unit of the data processing system; storing active data stock, wherein the redundancy data processing unit respectively stores an active data stock copy of each active data processing unit assigned to it; periodically determining if changes exist between current active data stock and the copy of active data stock, wherein each of the data processing units periodically ascertains if changes exist between its current active data stock and its respective active data stock copy stored in the redundancy data processing unit and transfers correction data to the assigned redundancy data processing unit describing any changes; updating stored copies of active data stock, wherein the redundancy data processing unit updates its active data stock copy of the respective transferring active data processing unit via the transferred correction data; and assuming the functions of a failed active data processing unit, wherein the redundancy data processing unit assumes the functions of the failed data processing unit based upon the stored active data stock copy of the failed data processing unit, wherein the method further comprises storing, in the redundancy data processing unit, copies of the current program versions of the active data processing units assigned to the redundancy data processing unit.