The Question is:
backup forced error in last sector read while backing up .rda files
The Answer is :
BACKUP is telling you that there might well be an error in the data
stored in the specific original disk sector involved -- this flag
indicates that BACKUP was not able to reliably read the data from
the disk, and flags the potential corruption.
Rewriting the faulty disk sector will trigger automatic bad block
recovery, and a good block will replace the faulty block.
Please contact Oracle if assistance in recovering data structures or
data stored in the particular sector of the Oracle Rdb database,
assuming that a BACKUP is not available. (The RDA file extension is
commonly used with the Oracle Rdb database environment. If this RDA
file is not part of an Oracle Rdb database, please disregard.)
$ HELP/MESSAGE FORCEDERROR
FORCEDERROR, forced error flagged in last sector read
Facility: SYSTEM, System Services
Explanation: This message applies only to devices governed by the mass
storage control protocol (MSCP). The data in this sector is
copied from another sector that had unrecoverable read errors.
This data is written with the Forced Error Indicator set to
show subsequent readers that the data is questionable.
User Action: Be aware that the contents of the sector are only a close
approximation of the data. Use the Backup utility to make a
copy of the original file and recover its contents.