External hard drive not recognized?

[KGIII]

Also, I've noticed this with USB devices from time to time. If you've plugged it in and plugged it, or if you've tried numerous operations on it, you have to reboot the whole computer for it to work.

This is a long page that I'm going to link next. It's my 'go to' when you find USB devices that can't be formatted.

Can't format my usb drive. I have already tried with mkdosfs and gparted

I have a MicroSD card in a USB adapter (which plugs into a USB port on my machine, and acts like a USB flash drive). I was using Unetbootin to make this a bootable USB flash drive with Kubuntu. But I

askubuntu.com

There's also a chance that the drive is just plain failing. If it's spinning platter and took a solid whack, that can happen.

 

[sphen]

I have salvaged USB flash drives by wiping the partition data from the drive. All data is utterly lost and unretrievable. This is a fix of last resort. There is no turning back. When you are done, you may be able to use the drive for new data. Can you trust it?

I wipe the USB drive from the Terminal on a Mac. Why Mac? Because that is what I have and use today. I am convinced the same solution will work from Linux.

SEVERE DATA LOSS WARNING:
-> You must be sure of the proper IDENTIFIER for your USB drive. If you make a mistake, you could easily wipe all of the data from your primary drive or another drive. BE VERY CAREFUL!!

dd bs=4096 if=/dev/zero of=/dev/IDENTIFIER

sudo dd bs=4096 if=/dev/zero of=/dev/IDENTIFIER

If you are impatient, you can stop the command with CTRL-C - the partition table is wiped quickly, and wiping the rest of a flash drive is unimportant.

Once the partition table is wiped, I format the USB drive using Mac, Windows, or Linux.
-> Sometimes it helps to format the drive just plain old FAT (MS DOS) with MBR. Once that works, you should be able to format it any way you want.

Mac Only Hints:
Find IDENTIFIER names:

diskutil list

Unmount a drive that you want to wipe. First ask yourself, why is it mounted??? Are you sure you have the correct drive??? ... then ask both questions again ...

diskutil unmountDisk /dev/IDENTIFIER

.

Sorry to be posting a Mac-based solution, but it is what I use that works for me. I am convinced that the same solution works from Linux. I confess that I struggle to figure out which device IDENTIFIER to use with Linux. It is just a web search away.

Note that USB drives can fail in various permanent ways that cannot be recovered. If the USB drive is old and has been used extensively with many writes, it could be "used up" with a unrecoverable failure.

I just looked online, and the price of USB flash drives is so low that recovering one for reuse does not seem worth the hassle or risk to me.

 

[bob466]

OP,

Did you solve your problem...if so let us know...did any advice given help. ?