Cannot see external usb hard drive Ubuntu 20.04 X64

**simon-webb** · January 24th, 2021

Wow, that's really useful to know. It won't be the issue in this case (as this is a FAT32 drive) but it's a potentially serious problem I'd never heard of. I'm surprised Windows doesn't just unmount external drives prior to hibernation: I wonder if it warns users that they need to plug all such drives back in before powering back on...otherwise (if the external drive is simply unplugged and packed away when the computer comes out of hibernation) presumably the data corruption (that the locking of the external drive aims to avoid) could still happen. Seems like a good reason to stick to vfat on USB drives.

**ajgreeny** · January 24th, 2021

You can check the end lines of dmesg by piping the output to tail with command

Code:

dmesg | tail

which by default shows the final 10 lines, I think.

That is big help in situations like yours, saves a long search of huge text files.

**simon-webb** · January 25th, 2021

Yep, 10 lines by default...or if you want to see a few more, you can e.g.

Code:

dmesg | tail -n 20

to view the last 20 (same as for "head", which defaults to the first 10 lines but can dump as many or as few lines as you want with the -n switch).

Are you sure the drive is physically OK...do you have another machine with which you can confirm that it's still a working drive?

**TheFu** · January 25th, 2021

dmesg -w maybe easier. It is basically dmesg|tail -f

Also, sudo is not needed with dmesg ... er ... yet. There have been some discussions about properly locking log files, so sometime in the next few releases, sudo may become necessary.

As for the OP using fat32 or some other file system like exfat, it is possible to make a little mistake. On some linux distros, exfat support is not standard. Extra packages need to be installed.

**vafred69** · January 29th, 2021

OK Sorry it's been so long but I found the problem. It was a bad USB Port. I plugged another portable hard drive into the same port and it was found fine. Then I plugged the one I was having the problem with into another port and it is found fine.

Thank you all for all your help It was my fault as I should have checked that before.
Fred Watson

**TheFu** · January 29th, 2021

vafred69 - not uncommon. We've all done it. There's something about having to explain stuff to someone else that gets our troubleshooting hats working.
In general, best to try and isolate what you think is the issue as much as possible.

Hardware, software, cables. Think logically. Simplify and test. Do that over and over. until the only thing left is too small to split apart for testing, then replace that part/software/cable.