This tool decodes SCSI Request Sense data and Command Descriptor Blocks (CDBs) to help diagnose issues with vintage SCSI devices. When BlueSCSI operates in initiator mode and encounters an error from a connected drive, the sense data reveals what went wrong.
Whether you're troubleshooting a stubborn hard drive, debugging a CD-ROM that won't mount, or diagnosing communication issues with a tape drive, this decoder translates cryptic hex bytes into human-readable error information.
When a SCSI device encounters an error, it returns Request Sense data containing detailed diagnostic information. This 18+ byte response includes:
To use this decoder, copy the hex bytes from your BlueSCSI log output after "RequestSense response:" and paste them below. The format should be space-separated hex values like 0x70 0x00 0x05 0x00...
A Command Descriptor Block (CDB) is the command packet sent from an initiator to a SCSI target device. Each CDB specifies an operation code and parameters like logical block addresses and transfer lengths.
Common SCSI commands include:
Paste your CDB hex bytes below to decode the command structure:
The sense key is a 4-bit code indicating the general category of error. Here are the standard SCSI sense keys:
| Code | Name | Description |
|---|---|---|
| 0x00 | No Sense | No error or no sense data available |
| 0x01 | Recovered Error | Command completed with recovery action by the device |
| 0x02 | Not Ready | Device is not ready (e.g., no media, spinning up) |
| 0x03 | Medium Error | Unrecoverable read/write error on the media |
| 0x04 | Hardware Error | Non-recoverable hardware failure |
| 0x05 | Illegal Request | Invalid command or parameter (common with incompatible commands) |
| 0x06 | Unit Attention | Device was reset or media changed |
| 0x07 | Data Protect | Write-protected media or read-only device |
| 0x08 | Blank Check | Blank or erased media encountered (tape drives) |
| 0x0B | Aborted Command | Device aborted the command |
| 0x0D | Volume Overflow | Physical end of media reached (tape drives) |
| 0x0E | Miscompare | Data comparison mismatch during verify |
BlueSCSI's initiator mode allows the device to act as the SCSI host, communicating with real SCSI devices like hard drives, CD-ROMs, and tape drives. When a connected device reports an error, BlueSCSI logs the Request Sense response in its log file. Use this tool to decode those responses and understand what the device is reporting.
For more information about BlueSCSI and its capabilities, visit the BlueSCSI homepage or check the BlueSCSI Docs.