Patent ID: 8479045

Claim:
A controller for a disk array device, for recovering data stored in a cache memory, upon recovery from a power failure, comprising: a nonvolatile memory configured to include a plurality of access ports, and have cache data written and stored therein which is stored in the cache memory at a time of occurrence of the power failure; and a data transfer section which comprises: a reading unit configured to read the cache data stored in said nonvolatile memory in units of a predetermined data transfer size and write the cache data back in the cache memory, an erasing unit configured to erase data stored in said nonvolatile memory, and a control unit configured to be operable when recovery from the power failure is detected, to perform a power recovery process in which said control unit specifies different ones of said access ports for said reading unit and said erasing unit, respectively, thereby causing said reading unit and said erasing unit to operate in parallel, and sets the predetermined data transfer size as appropriate according to a state of occurrence of an error during data transfer by said reading unit, such that the cache data is restored in the cache memory.