I was attempting to create a bootable usb thumbdrive from the ubuntu install cd using UNetBootin. Unfortunately, I accidental wrote the live cd to my 500gb usb external drive (which was almost completely filled with important files). I noticed I had made this mistake almost as soon as it happened. I quickly unplugged the usb hard drive. Ubuntu is no longer able to mount the harddrive. I believe the disk was originally formated ntfs or ext3, but I forget.

I want to recover my data.

  1. How can I determine the file-system type(ntfs or ext3) without mounting the disk?
  2. Has anyone done this and recovered all or some of there data? How?
  3. What /suggestions does server-fault have?
  4. Can I recover in-place? That is do I need to find a >500GB harddrive onto which I can recover too?
  5. Is there anyway to just recover the file system.
  6. Can I see what files are intact?
  7. Any favourite/best tools for recovery?

Thanks, and feel free to tell me that keeping backups is important (A backup NAS is in the main).


  • I'm looking for free solutions
  • I have read this earlier question 'how-do-you-repair-a-damaged-or-corrupt-partition', but I'm unsure if it applies completely to my case. As in my case I likely overwrote a fairly small amount of contiguous data at the beginning of the disk.
  • As I was following verbatim the ubuntu directions on building a bootable usb drive, I'm assuming people have done exactly what I've done in the past, and I am interested in hearing how they solved it. Furthermore it is a case people are likely to run into in the future, so a set of clear directions on how to solve it would be extremely helpful for the community.

4 Answers 4


you can use this tool http://www.cgsecurity.org/wiki/TestDisk

  • I once used TestDisk to recover from accidental partition deletion on my USB drive. Not sure if it can help with accidental formatting but it may be worth a look. At the time I used it the documentation was slightly cryptic in places, but not too terrible. Jun 18, 2009 at 19:31
  • TestDisk has been my best friend for a few data recovery jobs and every time my Galaxy S5 (now my Blu R1HD - FML) trashed its SD card when it runs its battery out (the latter now backs up to my home PC every night). One thing to note is that it will create files with very unintuitive names, so some sifting will be necessary. Jan 3, 2018 at 2:33

When you recover a drive, it is always better to make a copy in an image file (with dd for example). I understand that in your case, 500GB can be difficult. But it avoids that you irreversibly damage your data using any tool you find on the internet, particularly if you have never used it and if you don't know if you can trust it.

Then, have a look at PhotoRec to recover files removed accidentally:


It is distributed under the GPL and supports NTFS as well as EXT2/EXT3 filesystems.

A last remark: "Keeping backups is important" :)

  • Looks like some great software! I've never heard of this before, thanks. Jun 18, 2009 at 22:50

Can I recover in-place? That is do I need to find a >500GB harddrive onto which I can recover too?

The first thing you should do is make a complete image copy of your drive, and work on that. Don't run the risk that you do something stupid to the good 499GB of your drive.


Zero Assumption Recovery (not free)


  • Thanks, I updated the question to specify free solutions, but I appreciate the help. Jun 18, 2009 at 18:59

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