I know that in general this means that I have a "bad disk". But I'm after a more specific reason for why I am getting these messages from the kernel:

sd 15:0:0:0: [sda] Attached SCSI disk
sd 15:0:0:0: [sda] Unhandled sense code
sd 15:0:0:0: [sda]  Result: hostbyte=0x10 driverbyte=0x08
sd 15:0:0:0: [sda]  Sense Key : 0x3 [current] 
sd 15:0:0:0: [sda]  ASC=0x11 ASCQ=0xc
sd 15:0:0:0: [sda] CDB: cdb[0]=0x28: 28 00 00 00 00 00 00 00 20 00
end_request: critical target error, dev sda, sector 0

I've had a bit of a search and I see that 0x3 sense key means "Medium error" and ASC=0x11 means "Read error". But it is still a mystery as to what the ASCQ=0xc means.

The device is a bus powered USB drive which reports its model as "TOSHIBA MQ01ABB200"


From the SCSI2-Draft standard (the only one I have that isn't a PDF):

Table D.1  (continued)
|           D - DIRECT ACCESS DEVICE                                          |
|           .  .W - WRITE ONCE READ MULTIPLE DEVICE                           |
|           .  .  .O - OPTICAL MEMORY DEVICE                                  |
|           .  .  .  .                                                        |
| ASC ASCQ  DTLPWRSOMC  DESCRIPTION                                           |
| --- ----              ----------------------------------------------------- |

(obviously, that's not the entire table D.1)

  • 2
    FWIW, www.t10.org lets you download the most recent drafts of most all of their standards. www.t13.or for ATA standards, too. – etherfish Feb 12 '14 at 20:26
  • "Optical memory device"? Not sure what that means in this context. This is a rotating disk device. – Austin Feb 12 '14 at 20:27
  • SCSI is very old. Back in the day, there were optical drives. (one was the main drive in the NeXT cube) [think CD/DVD/Bluray these days] – Ricky Feb 12 '14 at 20:32
  • The interesting one is the "W"... write once cannot be rewritten. – Ricky Feb 12 '14 at 20:35
  • Well, that's even more mysterious. This is definitely a multiple write device. Also, it's strange advise to rewrite data onto a write once device. – Austin Feb 12 '14 at 21:07

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