If an error occurs when a record is being written, an attempt is made to successfully write the error record. If writing is not successful after several retries and error recovery is not requested, SORT terminates. If error recovery is requested, SORT marks the row of the disk containing the error record as bad disk. If possible, SORT continues in full error recovery mode; otherwise, SORT displays “SORT ERROR #32” and continues with error recovery reset. If SORT is in the stringing phase, an attempt is made to write the error record and if the attempt is unsuccessful, SORT terminates. If SORT is in the merge phase, it backtracks to the desired point of restarting the merge phase. At most, one row of disk is marked for each occurrence of an output error for the work file.