Information recording apparatus, information playback apparatus, and formatting method

An information recording apparatus comprising:

• a divider configured to divide recording data into a plurality of recording data blocks for each predetermined recording unit;
• a generator configured to set, as a first block set, n recording data blocks recorded in corresponding areas in file system management areas of n, first to nth (n:
• integer, n≧2) storages, and generate first parity data from the n recording data blocks forming the first block set;
• and
• a recorder configured to record the n recording data blocks forming the first block set in first areas in the file system management areas of the n storages out of corresponding first areas in the file system management areas of the n storages and one storage, and record the first parity data in the first area in the file system management area of the one storage,
• wherein the generator is configured to extract, from the plurality of recording data blocks, n recording data blocks for forming the first block set, and configured to, when m (m:
• integer, m≧1) recording data blocks smaller in number than the n recording data blocks remain, generate temporary parity data based on the remaining m recording data blocks, and
• the recorder is configured to record the remaining m recording data blocks in corresponding second areas in the file system management areas of m storages out of the n storages, out of corresponding second areas in the file system management areas of the n storages and the one storage, and configured to record the temporary parity data outside the file system management area of at least one storage out of the n storages and the one storage.