Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

All of a sudden I am not able to use properly my external HDD and Pendrives.

The disks are correctly mounted, but navigating them is extremely slow and when I try to copy files from my laptop hard-disk to external drives, the copy starts, but then fails.

I have tried several devices on both my usb ports (one 3.0, one 2.0).

How can I diagnose what is the problem and possibly fix it?

share|improve this question
Have you tested the HDD and Pendrives in other pc? – ThiagoPonte Oct 1 '12 at 22:41
yes they work fine.. – lucacerone Oct 2 '12 at 6:39
up vote 0 down vote accepted

First of all you must check both discs (internal and external) for bad sectors or other problems.

Tools for this can be:


Install by typing in console:

sudo apt-get install gsmartcontrol

Perform some tests to see if there's something wrong.

I also really advise you to read The Beginner’s Guide to Linux Disk Utilities

Also check /var/log/messages for errors or run dmesg after the copy of files failed.

If unmounting of the filesystem is needed, the best option is to use a livecd with a set of tools to help diagnose and repair a bad filesystem, for example:

Hirens Boot CD

Download and burn into a CD, boot that CD, and use the existing tools for Disc Diagnose and Repair.

Go to your discs manufacturer website, and look for any disc utility they can have, to scan for problems. I know that Maxtor and Samsung, have tools of their own.

Important question: Your external HDD and Pendrives work OK in other operating systems or in another PC?

This is important, as it can help rule out the defective hardware (the external drives, your USB ports, or your internal disc)

share|improve this answer
It is a bit a vague answer, can you give me some more details? – lucacerone Oct 2 '12 at 6:40
My advise is that you use some tools to test your discs to see if they work ok. Doing some tests with the tools i said would help to se if the discs are OK. After that, if tests are OK, you should try to see the errors that are displayed when copying files. – LnxSlck Oct 2 '12 at 11:35
Using gsmartcontrol didn't find any error. – lucacerone Oct 3 '12 at 11:03
I would like to use fsck and badsector as explained in the guide.. but I am not sure if I can unmount safely my main hd.. is there a way I can do it without using a live distribution? I don't have any on cd and since my usb doesn't work I can't install one there.. – lucacerone Oct 3 '12 at 11:08
See my updated answer – LnxSlck Oct 3 '12 at 11:34

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.