Quantum DLTtape DLT 4000, Product Manual

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SCSI Commands
Quantum DLT 4000 Tape Drive 5-119
READ Command (08h) (continued)
Filemark, End-of-Data, and End-of-Medium/Partition Handling
If the tape drive reads a Filemark, it returns a CHECK CONDITION status.
Within the sense data, the Filemark and Valid bits are set and the Sense Key
field is set to NO SENSE. The information fields contain the residue count. The
Additional Sense Code and Additional Sense Code Qualifier fields are set to
FILEMARK DETECTED. Upon termination, the medium is logically positioned
after the Filemark (EOM).
If the drive detects End-of-Data (EOD) during a READ, the drive returns a
CHECK CONDITION status. Within the sense data, the Valid bit is set and the
Sense Key field is set to BLANK CHECK. The End-of-Medium (EOM) bit may be
set if the drive determines that the tape is positioned past the PSEN marker. The
information fields contain the residue count. The Additional Sense Code
Qualifier fields are set. Upon termination, the medium is physically positioned
before EOD and after the last block on tape.
The meaning of EOD is different for a READ command than for a WRITE-related
command. EOM is reported only when the physical EOM or End-of-Partition
(EOP) is encountered. The drive returns a CHECK CONDITION status. The
EOM and Valid bits are set and the Sense Key is set to MEDIUM ERROR. The
information fields contain the residue count and the Additional Sense Code and
Additional Sense Code Qualifier fields are set to EOM/P DETECTED. The tape
is physically positioned at EOM/P.
If any READ command cannot be successfully completed, the drive returns a
CHECK CONDITION status. Further commands should attempt to move past
the anomaly and to complete successfully.