Patent ID: 7085886

Claim:
A method for storing data in a data processing system having a storage controller coupled to at least one host computer, the method comprising: directing first modified data in a first cluster of the storage controller be stored in a preserved area of memory of a second cluster of the storage controller in a normal operating mode; directing second modified data in the second cluster be stored in a preserved portion of memory of the first cluster in the normal operating mode; upon detection of a power failure in the storage controller: continuing to operate the storage controller under temporary battery power: directing the first modified data be stored in a first disk storage device in the first cluster; directing the second modified data be stored in a second disk storage device in the second cluster; directing the first modified data be transferred from the preserved area of the second cluster to the second disk storage device; and directing the second modified data be transferred from the preserved area of the first cluster to the first disk storage device; attempting to restore the storage controller to the normal operating mode; upon a failure of the first cluster to recover after the power failure, enabling the second cluster to process the first modified data of the first cluster through the second storage device.