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

NeddySeagoon · Posted: Thu Oct 08, 2015 6:06 pm Post subject:

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.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Amity88 · Posted: Sat Oct 10, 2015 2:11 pm Post subject:

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:

Roman_Gruber · Posted: Sat Oct 10, 2015 5:09 pm Post subject:

NeddySeagoon · Posted: Sat Oct 10, 2015 6:53 pm Post subject:

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.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Amity88 · Posted: Sun Oct 11, 2015 3:11 am Post subject:

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:

NeddySeagoon · Posted: Sun Oct 11, 2015 10:15 am Post subject:

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

Amity88 · Posted: Tue Oct 13, 2015 1:43 am Post subject:

Neddy,
I checked online for the warranty status. Fortunately it's still in warranty!

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).
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