Release 10.1A: OpenEdge Data Management:
Database Administration

CRC codes and redundancy in backup recovery

To recover corrupted backup blocks, PROREST relies on:

CRC codes to identify bad blocks. A CRC code is automatically calculated for each database backup block whether or not you specify a redundancy factor.
Error-correction blocks to recover bad blocks. Error-correction blocks are included in the backup only if you explicitly request them with the -red parameter of the backup utility.