# USB Hardisk powers on but not in /dev

## Amity88

Hi,

      I have a WD Elements USB 3.0 external disk which doesn't seem to be recognized in any OS after I accidentally pulled out the cable while copying a bunch of files. I can hear the disk power on, the LED lights up and lsusb seem to recognize it but the disk doesn't get listed in /dev. I couldn't even find it when I tried 

```
fdisk -l
```

fdisk only listed the other disks in my system. I've tried it on multiple computers and I've also tried using a different cable but I just can't seem to access the disk. I really would appreciate any tips/advice on getting this thing to work again.

----------

## NeddySeagoon

Amity88,

Power up your system,  then attach the HDD.

There should be something at the end of dmesg to say a usb device has been detected.

Is the HDD bus powered or does it have a separate PSU?

If its bus powered, be sure its connected to a USB3 port on the PC.

USB1/2 can only provide 500mA but USB3 will provide 900mA.  It matters to a HDD.

----------

## Amity88

Neddy,

          Good to see you again, just the sorta person I wanted to ask this question. The disk is bus powered and I did try with the USB3 ports. On my linux laptop, it still doesn't show up in /dev but on my Windows desktop it shows up. However, it seems impossible to initialize the device. It gives an I/O error when I try it. I've posted the output of dmesg below:

```

[  122.831951] usb 1-1: new high-speed USB device number 2 using

xhci_hcd

[  122.848112] usb 1-1: device descriptor read/8, error -71

[  122.967871] usb 1-1: device descriptor read/8, error -71

[  123.127589] hub 1-0:1.0: unable to enumerate USB device on port 1

[  123.367256] usb 1-1: new high-speed USB device number 4 using

xhci_hcd

[  123.415682] usb 1-1: New USB device found, idVendor=1058,

idProduct=10a8

[  123.415689] usb 1-1: New USB device strings: Mfr=1, Product=2,

SerialNumber=3

[  123.415693] usb 1-1: Product: Elements 10A8

[  123.415696] usb 1-1: Manufacturer: Western Digital

[  123.415699] usb 1-1: SerialNumber: 575837314138333435383332

[  123.570757] Initializing USB Mass Storage driver...

[  123.570903] scsi7 : usb-storage 1-1:1.0

[  123.570975] usbcore: registered new interface driver usb-storage

[  123.570977] USB Mass Storage support registered.

[  124.570247] scsi 7:0:0:0: Direct-Access     WD       Elements 10A8 

  1042 PQ: 0 ANSI: 6

[  124.571950] sd 7:0:0:0: Attached scsi generic sg3 type 0

[  124.572990] sd 7:0:0:0: [sdc] Spinning up

disk..................................................ready

[  175.056019] sd 7:0:0:0: [sdc] 1953458176 512-byte logical blocks:

(1.00 TB/931 GiB)

[  175.056369] sd 7:0:0:0: [sdc] Write Protect is off

[  175.056382] sd 7:0:0:0: [sdc] Mode Sense: 53 00 10 08

[  175.056734] sd 7:0:0:0: [sdc] No Caching mode page found

[  175.056742] sd 7:0:0:0: [sdc] Assuming drive cache: write through

[  175.058022] sd 7:0:0:0: [sdc] No Caching mode page found

[  175.058030] sd 7:0:0:0: [sdc] Assuming drive cache: write through

[  184.414545] sd 7:0:0:0: [sdc]  Result: hostbyte=DID_OK

driverbyte=DRIVER_SENSE

[  184.414554] sd 7:0:0:0: [sdc]  Sense Key : Aborted Command

[current] 

[  184.414560] sd 7:0:0:0: [sdc]  Add. Sense: No additional sense

information

[  184.414566] sd 7:0:0:0: [sdc] CDB: Read(10): 28 00 00 00 00 00 00

00 08 00

[  184.414578] end_request: I/O error, dev sdc, sector 0

[  184.414585] Buffer I/O error on device sdc, logical block 0

[  195.006142] sd 7:0:0:0: [sdc]  Result: hostbyte=DID_OK

driverbyte=DRIVER_SENSE

[  195.006151] sd 7:0:0:0: [sdc]  Sense Key : Aborted Command

[current] 

[  195.006157] sd 7:0:0:0: [sdc]  Add. Sense: No additional sense

information

[  195.006163] sd 7:0:0:0: [sdc] CDB: Read(10): 28 00 00 00 00 00 00

00 08 00

[  195.006175] end_request: I/O error, dev sdc, sector 0

[  195.006181] Buffer I/O error on device sdc, logical block 0

[  205.586753] sd 7:0:0:0: [sdc]  Result: hostbyte=DID_OK

driverbyte=DRIVER_SENSE

[  205.586761] sd 7:0:0:0: [sdc]  Sense Key : Aborted Command

[current] 

[  205.586767] sd 7:0:0:0: [sdc]  Add. Sense: No additional sense

information

[  205.586773] sd 7:0:0:0: [sdc] CDB: Read(10): 28 00 00 00 00 00 00

00 08 00

[  205.586785] end_request: I/O error, dev sdc, sector 0

[  205.586792] Buffer I/O error on device sdc, logical block 0

[  216.177369] sd 7:0:0:0: [sdc]  Result: hostbyte=DID_OK

driverbyte=DRIVER_SENSE

[  216.177377] sd 7:0:0:0: [sdc]  Sense Key : Aborted Command

[current] 

[  216.177383] sd 7:0:0:0: [sdc]  Add. Sense: No additional sense

information

[  216.177389] sd 7:0:0:0: [sdc] CDB: Read(10): 28 00 00 00 00 00 00

00 08 00

[  216.177401] end_request: I/O error, dev sdc, sector 0

[  216.177408] Buffer I/O error on device sdc, logical block 0

[  222.366828] hp_wmi: Unknown event_id - 10 - 0x1

[  223.414065] hp_wmi: Unknown event_id - 10 - 0x1

[  226.768905] sd 7:0:0:0: [sdc]  Result: hostbyte=DID_OK

driverbyte=DRIVER_SENSE

[  226.768913] sd 7:0:0:0: [sdc]  Sense Key : Aborted Command

[current] 

[  226.768919] sd 7:0:0:0: [sdc]  Add. Sense: No additional sense

information

[  226.768925] sd 7:0:0:0: [sdc] CDB: Read(10): 28 00 00 00 00 00 00

00 08 00

[  226.768937] end_request: I/O error, dev sdc, sector 0

[  226.768944] Buffer I/O error on device sdc, logical block 0

[  226.768998] ldm_validate_partition_table(): Disk read failed.

[  237.348547] sd 7:0:0:0: [sdc]  Result: hostbyte=DID_OK

driverbyte=DRIVER_SENSE

[  237.348555] sd 7:0:0:0: [sdc]  Sense Key : Aborted Command

[current] 

[  237.348561] sd 7:0:0:0: [sdc]  Add. Sense: No additional sense

information

[  237.348567] sd 7:0:0:0: [sdc] CDB: Read(10): 28 00 00 00 00 00 00

00 08 00

[  237.348579] end_request: I/O error, dev sdc, sector 0

[  237.348586] Buffer I/O error on device sdc, logical block 0

[  248.084077] sd 7:0:0:0: [sdc]  Result: hostbyte=DID_OK

driverbyte=DRIVER_SENSE

[  248.084085] sd 7:0:0:0: [sdc]  Sense Key : Aborted Command

[current] 

[  248.084092] sd 7:0:0:0: [sdc]  Add. Sense: No additional sense

information

[  248.084097] sd 7:0:0:0: [sdc] CDB: Read(10): 28 00 00 00 00 00 00

00 08 00

[  248.084109] end_request: I/O error, dev sdc, sector 0

[  248.084116] Buffer I/O error on device sdc, logical block 0

 

```

----------

## Roman_Gruber

 *Quote:*   

> [  123.415693] usb 1-1: Product: Elements 10A8
> 
> [  123.415696] usb 1-1: Manufacturer: Western Digital
> 
> [  123.415699] usb 1-1: SerialNumber: 575837314138333435383332 

 

Well, the usb - hdd controller works and sends back some informations. so the hdd itself seems to be present, but I wonder about the partition table here.

 *Quote:*   

> [  226.768937] end_request: I/O error, dev sdc, sector 0
> 
> [  226.768944] Buffer I/O error on device sdc, logical block 0
> 
> [  226.768998] ldm_validate_partition_table(): Disk read failed.

 

No idea if the parittion table is dead or something else.

WARNING: you may run gparted and re/create a new partition table, but that will destroy your data or make it unaccessable. not recommended. Than you may run testdisk and recover the data to a spare drive.

It may be also advised to check the wiring, if the connectors in the enclosre are proper mounted to the drive / outside of the drive.

--

Because you mentioned windows. is the drive useable in windows? is the data accessable?

----------

## NeddySeagoon

Amity88,

Well, the drive electronics still work.

It looks like the drive spins up, becomes ready and responds to the identify command.

Then, when the kernel tries to read the MSDOS partition table in LBA 0, it can't.

Does /dev/sdc exist or did the failure prevent even  /dev/sdc being created.

If you have /dev/sdc, you can try to get LBA 0 to relocate by writing to it.

This will destroy your MSDOS partition table in the process but its gone angway..

If you use GPT you don't care.

You can use testdisk to scan the drive and find potential filesystem starts, then recreate your partition table.

Don't let testdisk write the partition table for you.  You only need the primary partitions back and the logical partions will just magically appear.

----------

## Amity88

Hi guys,

            I think it has gotten worse now, the dmesg has changed and seems to keep complaining about a reset. At this point I don't care about the data, so I've tried dd-ing zeros to /dev/sdc but then I get an error saying "no such device or address" despite showing up in /dev. I'm really surprised how easily this drive got sick, all I did was interrupt a copy by accidentally pulling the USB plug.

here is the new dmesg:

```

[19427.149742] usb 4-2: new SuperSpeed USB device number 4 using

xhci_hcd

[19427.166371] usb 4-2: New USB device found, idVendor=1058,

idProduct=10a8

[19427.166378] usb 4-2: New USB device strings: Mfr=1, Product=2,

SerialNumber=3

[19427.166382] usb 4-2: Product: Elements 10A8

[19427.166385] usb 4-2: Manufacturer: Western Digital

[19427.166388] usb 4-2: SerialNumber: 575837314138333435383332

[19427.167042] scsi10 : usb-storage 4-2:1.0

[19432.175662] scsi 10:0:0:0: Direct-Access     WD       Elements 10A8

   1042 PQ: 0 ANSI: 6

[19432.177366] sd 10:0:0:0: Attached scsi generic sg3 type 0

[19432.178320] sd 10:0:0:0: [sdc] Spinning up disk.....

[19464.901073] usb 4-2: reset SuperSpeed USB device number 4 using

xhci_hcd

[19469.910368] usb 4-2: device descriptor read/8, error -110

[19470.014197] usb 4-2: reset SuperSpeed USB device number 4 using

xhci_hcd

[19475.023744] usb 4-2: device descriptor read/8, error -110

[19475.183597] usb 4-2: USB disconnect, device number 4

[19475.183604] sd 10:0:0:0: Device offlined - not ready after error

recovery

[19475.183646] ready

[19475.183675] sd 10:0:0:0: rejecting I/O to offline device

[19475.183701] sd 10:0:0:0: rejecting I/O to offline device

[19475.183716] sd 10:0:0:0: rejecting I/O to offline device

[19475.183726] sd 10:0:0:0: [sdc] READ CAPACITY failed

[19475.183732] sd 10:0:0:0: [sdc]  Result: hostbyte=DID_NO_CONNECT

driverbyte=DRIVER_OK

[19475.183740] sd 10:0:0:0: [sdc] Sense not available.

[19475.183815] sd 10:0:0:0: [sdc] Write Protect is off

[19475.183820] sd 10:0:0:0: [sdc] Mode Sense: 00 00 00 00

[19475.183903] sd 10:0:0:0: [sdc] Asking for cache data failed

[19475.183914] sd 10:0:0:0: [sdc] Assuming drive cache: write through

[19475.184753] sd 10:0:0:0: [sdc] READ CAPACITY failed

[19475.184767] sd 10:0:0:0: [sdc]  Result: hostbyte=DID_NO_CONNECT

driverbyte=DRIVER_OK

[19475.184779] sd 10:0:0:0: [sdc] Sense not available.

[19475.184890] sd 10:0:0:0: [sdc] No Caching mode page found

[19475.184901] sd 10:0:0:0: [sdc] Assuming drive cache: write through

[19475.184911] sd 10:0:0:0: [sdc] Attached SCSI disk

[19475.185562] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called

with disabled ep ffff880283dbdcc0

[19475.185570] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called

with disabled ep ffff880283dbdd00

```

----------

## NeddySeagoon

Amity88,

Try smartmontools on it but you need a /dev node for that.

If its under warranty, send it back.

The WD Warranty Checker says Invalid Serial Number: 575837314138333435383332.

I only tried the UK as thats where I am

Compared to WD drives I've returned, it does look a bit odd.

From smartctl, one of min shows

```
Model Family:     Western Digital Caviar Green (AF)

Device Model:     WDC WD20EARS-00MVWB0

Serial Number:    WD-WCAZA1872552
```

This makes me think the identify command ran but returned rubbish.

The data returned by the identify command is held in persistant memory on the drive.

Speculating further, its in FLASH memory, or rather, was in FLASH memory.

----------

## Amity88

Neddy,

          I checked online for the warranty status. Fortunately it's still in warranty!   :Very Happy:   Hopefully my little tinkering wouldn't disqualify me (WD Elements outercasing is just clipped on and very easy to remove, don't even need tools).

----------

