Method of writing data and channel adapter

A method of writing data in which a record in a storage unit is updated according to instructions from an external unit in the storage unit that manages by fixed-length data the record of the variable-length data format that includes a predetermined field, comprising:

• receiving a record of an updated variable-length data format;
• reading fixed length data from the storage unit that corresponds to the received record;
• reading data in which for an update field that includes a content that is updated, the data is read from the record that is received and for a field other than the update field, the data is read from the data subjected to updating;
• check-code creating by calculating a field-checking code in units of field for the update field as well as calculating a block-checking code in units of a length of the fixed-length data, and calculating the block-check field in units of the length of the fixed-length data for a field other than the update field;
• and
• writing data by assembling the data that is read in the reading data and fixed-length data that includes the field-checking code and the block-checking code, by using the field-checking code and the block-checking code created in the checking the code, and transferring the data to the storage unit.

A channel adapter that writes and reads data, according to instructions from an external unit, in and from a storage unit that manages a record in a variable-length data format including a predetermined field, by fixed-length data, comprising:

• a data processing unit that creates a descriptor for writing the record in the storage unit upon receiving the request for writing a record in the variable-length data format and receiving the record;
• a writing data storage unit that stores the record received;
• and
• a data sending unit that has a data reading function of reading the record from the writing data storage unit based on the descriptor, an FCC creating function of creating a field-checking code for each field in the record that is read, a BCC creating function of creating a block-checking code in units of the fixed-length data for the record that is read, and a data writing function that includes assembling fixed-length data that includes the field-checking code as well as the block-checking code, by using the data read by the data reading function, the field-checking code created by the FCC creating function, and the block-checking code created by the BCC creating function, transferring the data in the storage unit to thereby writing the data in the storage unit.