Here is the list of the LTO key sense code and description. Taken from the eighth edition of the IBM TotalStorage LTO Ultrium Tape Drive SCSI Reference (July 2007).
Sense Key 0 (No Sense)
No Additional Sense Information - (unsolicited, no CA/CC)
Sense Key 1 (Recovered Error)
Write Error: A write error occurred, but was recovered. Data was successfully written to tape.
Read Error: A read error occurred, but was recovered. Data was successfully read from tape.
Sense Key 2 (Not Ready)
Initializing Command Required: A tape is present in the drive, but it is not logically loaded.
Sense Key 3 (Medium Error)
Medium Error/WORM Medium - Integrity Check: Set when the drive rejects a Read operation
because the current cartridge is a Suspicious WORM cartridge, and the WTRE bit is set to 0.
Sense Key 4 (Hardware or Firmware Error)
Manual Intervention Required: A tape is present in the drive but could not be loaded or unloaded
without manual intervention.
Sense Key 5(Illegal Request)
Position Past Beginning of Medium: A command that required the medium to be at BOP was
attempted when the medium was not at BOP (for example, Set Capacity).
Sense Key 6 (Unit Attention)
Transceiver Mode Changed To LVD: The drive detected a transceiver mode change from MSE
mode to LVD mode
Sense Key 7 (Data Protect)
Data Protect/WORM Medium - Integrity Check: Set when the drive rejects a Write operation
because the current cartridge is a Suspicious WORM cartridge
Sense Key 8 (Blank Check)
The drive detected an overtemperature condition. The currently loaded medium has been ejected.
Sense Key B (Aborted Command)
Initiator Detected Error Message Received
Sense Key D (Volume Overflow)
End-of-Partition/Medium Detected
Sense Key 0 (No Sense)
No Additional Sense Information - (unsolicited, no CA/CC)
Sense Key 1 (Recovered Error)
Write Error: A write error occurred, but was recovered. Data was successfully written to tape.
Read Error: A read error occurred, but was recovered. Data was successfully read from tape.
Sense Key 2 (Not Ready)
Initializing Command Required: A tape is present in the drive, but it is not logically loaded.
Sense Key 3 (Medium Error)
Medium Error/WORM Medium - Integrity Check: Set when the drive rejects a Read operation
because the current cartridge is a Suspicious WORM cartridge, and the WTRE bit is set to 0.
Sense Key 4 (Hardware or Firmware Error)
Manual Intervention Required: A tape is present in the drive but could not be loaded or unloaded
without manual intervention.
Sense Key 5(Illegal Request)
Position Past Beginning of Medium: A command that required the medium to be at BOP was
attempted when the medium was not at BOP (for example, Set Capacity).
Sense Key 6 (Unit Attention)
Transceiver Mode Changed To LVD: The drive detected a transceiver mode change from MSE
mode to LVD mode
Sense Key 7 (Data Protect)
Data Protect/WORM Medium - Integrity Check: Set when the drive rejects a Write operation
because the current cartridge is a Suspicious WORM cartridge
Sense Key 8 (Blank Check)
The drive detected an overtemperature condition. The currently loaded medium has been ejected.
Sense Key B (Aborted Command)
Initiator Detected Error Message Received
Sense Key D (Volume Overflow)
End-of-Partition/Medium Detected