Patent ID: 8259405

Claim:
A method for rewriting data to magnetic tape when an error is detected in a codeword object, comprising: forming a first synchronized codeword object (SCO) having first and second encoded processed user data units and one or more sync patterns, the first SCO being one of T SCOs in a first SCO set, the first user data unit being one of T user data unit in a first user data unit set within the first SCO set and the second user data unit being one of T user data unit in a second user data unit set within the first SCO set, where T is the number of physical tracks on the tape to which data is written simultaneously; writing the first SCO set to a first position on magnetic tape; reading the first SCO set immediately after the data is written; detecting an error in one of the user data units; forming a second SCO to include the user data unit set having the defective user data unit and, only if an error is not detected in a user data unit in the other user data unit set, to not include the other user data unit, the second SCO being one of T SCOs in a second SCO set; and rewriting the second SCO set to a position on the tape later than the first position.