Advanced Diagnostics SCSI Errors

SCSI POST error (QEET) codes

RETAIN H00727 SCSI Fixed Disk Diagnostic Error Return Codes [9XYY]

   The SCSI error codes for Advance Diagnostics are different from the SCSI POST error (QEET) codes provided in the HMM, Form #S52G-9971 - 01.  If SCSI errors occur during POST, the Advanced Diagnostics should be run prior to any parts being replaced.

   When the SCSI Fixed Disk Diagnostic Test detects a failure in a hard file, a 12 character error code is generated which consists of the 8 digit SCSI ERROR CODE, plus the 4 digit ERROR RETURN CODE.

   Error code 0210401H 9231 was provided by Advanced Diagnostics during an actual service incident. This error is decoded as:

    0210401H 9231     (actual error code)
    0210PLSC 9XYY     (decoding key)

   0210  - means non-removal fixed disk media (hard file).
   P     - PUN (Physical unit number, ie. SCSI ID=4)
   L     - LUN (Logical unit number, 0 on fixed disks)
   S     - micro channel slot of the SCSI adapter
   C     - capacity code of the specific fixed disk being tested

   9     --> UNIT REFERENCE CODE     (Important, See note below)
   X     --> SENSE KEY                   (Refer to Chart 1, below)
   Y |-----> ADDITIONAL SENSE CODE       (Refer to Chart 2, below
   Y |                                    00 - 5D are valid codes)

   The first 8 characters are not error specific and only point to the device under test.  The RETURN CODE is more specific to the failure and may be decoded by first referring to the SENSE KEY in Chart 1 and then referring to the ADDITIONAL SENSE CODES from chart 2 .  Some of the SENSE KEY and ADDITIONAL SENSE CODES represent a probable software problem.  Operating System software has the capability of receiving this information and using it to provide detailed error information to the user, or to execute error recovery processes.  The use of this capability varies by design from operating system to operating system.

Note: If the Unit Reference Code is other than a '9', the following SENSE KEY and ADDITIONAL SENSE CODES (Charts 1 and 2) have DIFFERENT meanings and SHOULD NOT be used.


NO SENSE KEY No sense key information is available
RECOVERED ERROR Last command completed successfully with recovery action performed by device.
NOT READY Logical unit addressed cannot be selected.
MEDIA ERROR Command terminated with non-recoverable error condition caused by an error in recorded data or a flaw in media (disk).
HARDWARE ERROR Device detected non-recoverable hardware error while performing a command or during diagnostic test.
ILLEGAL REQUEST Illegal parameter in command descriptor block or additional parameter supplied as data. Probable software error.
UNIT ATTENTION Device RESET by power-on sequence, bus DEVICE RESET message, HARD RESET, removable media was removed/inserted, or Mode Select command issued.
N/A (Unused)
ABORTED COMMAND Device aborted command.
N/A (Unused)
MISCOMPARE Source data did not match data read from media on Write Verify or Verify command.
N/A (Unused)


No Additional Sense 
Information Is Available
No Index Or Sector
Was Found
Low-level format drive. If diags run error-free, drive is serviceable.
Seek Incomplete Time required to physically move head/arm assembly or switch heads exceeds specified limits. Probable hardware failure.
Write Fault. Track position or write circuit fault detected during write. Not always a hardware failure.  A physical jolt to drive during write operation could cause this. Isolated occurrence does not mean a hardware failure.
Drive Not Ready Spindle motor speed out of spec or device requires a motor start command, command not issued.  Power-off-on and retest drive.
Track Following Error Actuator position can't be maintained over given track.  Probable hardware failure.
Write Error Failure occurred during write (probably with Verify on) and auto-reallocation of sector failed or not supported on this type drive. Low-level format or sector re-assigned.  If diags run error-free, drive is serviceable.
ID CRC Read error detected in ID field of sector during read or write.  Low-level format drive.  If diags run error free HD is serviceable.
Unrecoverable Read Error Occurred in the data field of the sector that could not be corrected.  Sector should be re-written, reassigned, or low-level format done. If diags run error-free, drive is serviceable.
No Record Found SCSI device can't find requested record.  Low-level format drive, retest.  If no errors occur, drive is serviceable.
Seek Positioning Error Positioning of head/arm assembly to a new location failed.  Probable hardware failure.
Data Synchronization 
Mark Error
Sync byte at data field cannot be detected.  Low-level format drive.  If diagnostics run error-free, the disk is serviceable.
Recovered Read Data
without ECC
ECC check bytes calculated from data read during first read operation doesn't match ECC check bytes appended to data field and did match on subsequent read operation.  Possible minor media defect. Rewrite, re-assign sector, or low level format drive and re-run diagnostics.  If no error is detected, disk is serviceable.
Recovered Read 
Data With ECC
ECC check bytes calculated from data read during first read doesn't match ECC check bytes appended to data field, ECC correction applied on subsequent read.  Possible minor media defect. Rewrite re-assign  sector or low level format drive and re-run diagnostics. If no error, fixed disk is serviceable.
Defect List Error Data error detected while reading manufacturing defect list or while reading or writing grown defect list.  Low-level format, ignore grown defect list, retest drive.  If no errors, drive is serviceable.
Parameter List
Length Error
Command operation code received by device invalid. Probable software problem.
Synchronous Data
Transfer Error
Error during data transmission.  Check cable connections, cable termination, excessive cable length, and retest.
Compare Error Data read from media doesn't match data written to media on a Write with Verify command.  Probable hardware problem.
Invalid Command
Operation Code
Command operation code received by device is not supported.
Illegal Logical 
Block Address
Logical block address requested outside range supported by device.  Probable software problem.
Illegal Field
In The CDB
Device detects unexpected values in any field of CDB (Command Descriptor Block) Probable software problem.
Illegal LUN LUN field in CDB not supported.  Probable software problem.
Illegal Field In The 
Parameters List
Device detects unexpected values in any field of parameter list.  Probable software problem.
Removable Medium
(Not applicable for fixed disk drives.)
Power-On Reset
Bus Device Reset
POR / bus device reset sense code indicates device (drive) reset.  Reset due to software issued commands or defective hardware.
Mode Select
Parameters Changed
Not a hardware failure. Software or diagnostic code problems [?].
Media Format
Media format appears corrupted or interrupted (power down, reset, etc.) prior to completion of Format Unit command. Format Unit command should be re-issued and must complete successfully for this error condition to be removed.
No Defect Spare
Location Available
Reassign Block Command cannot successfully complete because all available spare sectors used. Low-level format, ignore grown defect list, and retest drive.  If no errors, drive is serviceable.
Operating Condition 
On The Device Has 
Been Changed
This is probably a software error.
Component Failure Drive self-test diagnostics detected failure (Hardware) in device.
Message Reject Error Inappropriate or unexpected Message Reject received from SCSI Adapter/A or SCSI Adapter/A rejects a message twice.
Internal Controller Error Internal microprocessor detects incorrect status or receives an illegal request from device electronics.  Hardware failure.
Select/Re-Select Failed SCSI Adapter fails to respond to re-selection within 250ms after device gains bus arbitration.  Re-selection attempted second time before setting select/re-select failed status.
SCSI Interface 
Parity Error
Device detects incorrect parity on SCSI data bus (CABLE). Check cable connections, termination, length (max 6m or approx. 20 feet).
Initiator Detected Error SCSI Adapter/A detects error, sends retry message, detects error again, sends retry message 2nd time. Probable hardware problem.
Illegal Message
SCSI Adapter/A sends message that is not supported or is not in a logical sequence.  Probable software error.
Logical Unit Failed 
Self Configuration
Probably a hardware failure in device being tested.
Overlapped Commands 
Probable software error.
Predictive Failure 
Analysis Threshold
Predetermined number of errors reached. Back-up data and service/replace fixed disk as appropriate.

9595 Main Page