(Amended) A recording apparatus, comprising: a write/read unit capable of performing data writing in a second data unit, in which a plurality of first data units of a predetermined amount of data are consecutive, and data reading in the first data unit with respect to a recording medium; and a control unit that, in response to a rewrite instruction for data in the first data unit, instructs the write/read unit to generate write data in the second data unit using update data relevant to the rewrite instruction and recorded data read out from the recording medium and to write the write data at a non-recording address on the recording medium, generates or updates replacement information for associating an address at which the write data is written, as a replacement destination, with an address of a replacement source, and generates extended replacement information including validity/invalidity information for each piece of data in the first data unit in the write data, as information linked to the replacement information, according to predetermined conditions, wherein, in a case where required recorded data cannot be read out in reading of recorded data from the recording medium in response to the rewrite instruction, the control unit checks other addresses at which the required recorded data is recorded with reference to the extended replacement information and controls the write/read unit to read out data from the other addresses, in a case where recorded data required for generating the write data in the second data unit cannot be read out even if reading from all other addresses that can be checked with the extended replacement information is performed, the control unit determines that a read error has occurred, the control unit generates the write data in the second data unit by combining the update data relevant to the rewrite instruction and the read recorded data in a case where reading of the required recorded data from the recording medium is successful, and generates the write data in the second data unit by combining the update data relevant to the rewrite instruction and invalid data in a case where it is determined that the read error has occurred, and in a case where writing of the write data, which is generated by combining the update data relevant to the rewrite instruction and the recorded data, to the recording medium is performed, the control unit generates extended replacement information including the validity/invalidity information of existing extended replacement information and deletes the existing extended replacement information on condition that the extended replacement information for the recorded data is present. a write/read unit capable of performing data writing in a second data unit, in which a plurality of first data units of a predetermined amount of data are consecutive, and data reading in the first data unit with respect to a recording medium; and a control unit that, in response to a rewrite instruction for data in the first data unit, instructs the write/read unit to generate write data in the second data unit using update data relevant to the rewrite instruction and recorded data read out from the recording medium and to write the write data at a non-recording address on the recording medium, generates or updates replacement information for associating an address at which the write data is written, as a replacement destination, with an address of a replacement source, and generates extended replacement information including validity/invalidity information for each piece of data in the first data unit in the write data, as information linked to the replacement information, according to predetermined conditions, wherein, in a case where required recorded data cannot be read out in reading of recorded data from the recording medium in response to the rewrite instruction, the control unit checks other addresses at which the required recorded data is recorded with reference to the extended replacement information and controls the write/read unit to read out data from the other addresses, in a case where recorded data required for generating the write data in the second data unit cannot be read out even if reading from all other addresses that can be checked with the extended replacement information is performed, the control unit determines that a read error has occurred, the control unit generates the write data in the second data unit by combining the update data relevant to the rewrite instruction and the read recorded data in a case where reading of the required recorded data from the recording medium is successful, and generates the write data in the second data unit by combining the update data relevant to the rewrite instruction and invalid data in a case where it is determined that the read error has occurred, and in a case where writing of the write data, which is generated by combining the update data relevant to the rewrite instruction and the recorded data, to the recording medium is performed, the control unit generates extended replacement information including the validity/invalidity information of existing extended replacement information and deletes the existing extended replacement information on condition that the extended replacement information for the recorded data is present.