Tape Drive CRC error
In the backup server log files Hiback \ log \ hiserv.log and / or Hiback \ log \ multiplexer.log you can see the following or similar messages
... nt_tapeeod (\\. \ Tape0 [A2B0S0L0]): Data error (CRC check)
Any backup to tape must place the tape on End Of Data. This happens with a Skip-to-EOD command to the tape drive.
This base command can not be executed due to a CRC error.
A CRC error is an uncorrectable SCSI transmission error.
When such an error becomes apparent, one can be sure that there are also undiscovered bit errors, because the CRC computes mod (2), so it is either 0 or 1 and will not be detected if the upset bits result in the same checksum.
So it may be that the bit errors already exist for a while.
There may be something in the event log of the backup server.
A look into it may give more clues as to how long and how often the problem occurs.
The problem may be on the SCSI link (adapter, cable, chassis).
One customer reported that the parity errors had only disappeared after the chassis had been replaced by HP.
It can also be on the medium or in the drive hardware.
In any case, the tape drive manufacturer must be involved in the analysis.