Patent ID: 7225315

Claim:
A file system to control accessing files belonging in one of a plurality of directories comprising: a storage system having a plurality of volumes; a volume allocation table adapted to set the plurality of volumes for each directory; a write control module that divides each of the files in the directory on a block basis when a write command is received, and writes the same block into all the volumes set in the volume allocation table; a file allocation table that stores attributes and divided block information of the file written into the volumes; a block reading table in which numbers of blocks read out by one reading operation are respectively set for each of the volumes; and a read control module that controls to read data from each of the volumes; wherein a read control module, when a read command is received, is adapted to: determine a volume based on a the directory configuration by referring to the volume allocation table, determine the number of blocks to read from each of at least two of the volumes by referring to the block reading table, determine blocks to be read from each of the at least two volumes based on the volume, the number of blocks, and the block information which are defined in the file allocation table, and read date from determined blocks in the at least two volumes.