Patent ID: 7624324

Claim:
A file control system performing direct memory access transfer and including a plurality of file control devices, each of the file control devices being provided between a host computer and an external storage device and controlling writing and reading of data to the external storage device based on commands from the host computer, the file control system comprising: a first file control device among the plurality of the file control devices including: a first memory to store data of the external storage device and a first error detection code provided to the data in advance; a first consistency determination unit to check for consistency between data obtained from the first memory and the first error detection code; an error detection code changing unit to change, after performing the checking of the first consistency determination unit, an error detection code added to the obtained data from the first error detection code to a second error detection code; a data changing unit to change, when an inconsistency is detected by the first consistency determination unit, at least a part of the data of the processing result of the error detection code changing unit; and a direct memory access transfer execution unit to execute direct memory access transfer of the data of the processing result of the error detection code changing unit to a second file control device among the plurality of the file control devices, the second file control device including: a second memory to store the data received from the first file control device; a second consistency determination unit to check consistency between the second error detection code and the data associated to the second error detection code, which are included in the data received from the first file control device; and a data processing unit to discard the data received from the first file control device when an inconsistency is detected by the second consistency determination unit, and to store the data received from the first control device in the second memory when the inconsistency is not detected by the second consistency determination unit.