Patent ID: 7640388
Filing Date: 2009-12-29
Classification: G06F,G11C

Abstract:
1. A file storage apparatus for storing a file and management information of the file and reconstruction information of the management information, comprising: a first storage means for storing the file and the management file, wherein the first storage means includes a first volatile memory for temporarily storing data of the file, and a first non-volatile memory for storing data of the file being read out from the first volatile memory; a second non-volatile memory connected with the first storage means and for storing the reconstruction information; a second volatile memory; control means for controlling the first storage means and the second non-volatile memory to perform data write operations of the file, the management information, and the reconstruction information, wherein the reconstruction information includes a copy of an updated block of meta data of the file without including all of the meta data of the file, and wherein upon each access to the file, the control means writes the reconstruction information to the second non-volatile memory before writing an updated management information to the first storage means and the control means removes the reconstruction information from the second non-volatile memory after the updated management information is written to the first non-volatile memory; and power supply voltage monitoring means for monitoring a normal state or an abnormal state of a power supply voltage, wherein the control means divides the reconstruction information into a plurality of blocks, attaches, to an end of the reconstruction information, a predetermined code representing a completion of writing the reconstruction information to the second non-volatile memory and provides the plurality of blocks to the second non-volatile memory in order from the beginning of the plurality of blocks, wherein the second non-volatile memory completes writing a first block of the plurality of the blocks when the power supply voltage monitoring means detects the abnormal state of the power supply during the write operation of the first block, and the power supply voltage monitoring means inhibits writing a second block following the first block, wherein the control means assigns storage regions in the second volatile memory for storing the management information and the reconstruction information, and wherein upon each update of the file, the control means writes the updated management information to the storage region of the management information assigned to the second volatile memory, writes the reconstruction information corresponding to the update to the storage region of the reconstruction information assigned to the second volatile memory, copies the reconstruction information written in the storage region of the second volatile memory to the second non-volatile memory, and rewrites the updated management information written in the second volatile memory to the first non-volatile memory.