MD5 does not match, repair corrupted ISO easily

After downloading a huge file you might face a horrible moment. Say, you download a linux distribution's ISO file with a download manager (using direct link) which size is 2 gb. When you try to run it or after burning it in a DVD- when you try to install it, you find that the installer does not perform your desired task. In this time what will you do? Download that ISO file again? Or think that the ISO supplier company is a cheater? Now, friend do not think this way. There is an option to repair it. Yes, it is true. You do not need to download that huge file again nor think bad about the supplier company. Lets come to know the happy method of repairing a corrupted or problematic ISO file. So, you should ask: How to repair a download corrupted ISO file? Really?

You know I have download LinuxMint13 (Mate) but it failed to run on Virtualbox. I checked it's md5 following this How to check md5sum of ISO on Linux method. I am sorry to say that md5 hash does not match with supplied number. That is both number are not same. So, I have done some Googling and found a nice and helpful way to repair my corrupted ISO file.

size does not match downloaded linuxmint13.iso file
size does not match downloaded linuxmint13 iso
Look at the image above. The ISO file properties saying that it is  898.0 MB, but BitTorrent client display 655.7 MB size of that file. This is the problem. We like to use direct link to download, but it is risky for this reason. It could download as a corrupted file. So, no more talk and lets start the method to repair a corrupted downloaded ISO file.

You should have a torrent client to do this job. Download a torrent client. Most of them are free to download and use. I am using Transmission BitTorrent Client on my Ubuntu machine.


First of all find a torrent of the exact ISO and download it for about a minute. Then, stop and close the client. Now replace the torrent data file that you were downloading using the client with the corrupted ISO. Re-open the client and start the download. The client will perform a hash MD5 check on the current data to see what file segment downloads are necessary. If you correctly found a torrent of the exact ISO, the client will re-download the segment of the corrupted data and rebuild the file. In the end, you should be good to go!

3 comments:

  1. I have same problem about Linuxmint13. It is corrupted after downloaded with free internet download manager. I thought that I have to download same file again. I will try your solution now.

    ReplyDelete
  2. Thanks for this valuable suggestion. It has worked well for me but in a SLIGHTLY DIFFERENT way:

    Instead of:

    downloading the file through torrent for a minute, then closing it, then replacing by corrupted file and then restarting the download;

    what I did was that:

    put the corrupted iso image in the location* where the file will be downloaded by torrent, BEFORE STARTING THE TORRENT CLIENT. And then when I started the torrent client it checked the file and downloaded 10 or 15 MB of corrupted data and when I checked the md5sum with Cygwin. . . voila! it matched with the correct one. I was saved from re-downloading the 701 MB file on my costly 3G data pack.

    *(this location can be known by starting the client from the torrent file and looking at the location it prompts to save the file)

    I did this for "ubuntu-12.04-desktop-i386.iso".

    ReplyDelete
  3. Hello

    I repaired 4.1GiB file just by downloading 1.8MiB :)

    Thanks for your solution

    you made me very happy and teach me a good thing :)

    I hope enjoy your life

    ReplyDelete

Please help me to improve my English. Please Email me or comment below. Thanks...