Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

I need to check the integrity of burned DVDs so that I can be sure about my backed-up data.

I use DL-DVDs to take the backup. Earlier I used VSO Inspector software for the same but the day I switched to DL-DVDs the VSO Inspector gives me errors upon checking. I think the errors are because the switching of layer writing involves some dummy data somewhere. Secondly, it's damned slow for checking. I believe if there is a utility that can read all files (not the disk surface) and report if some files are unreadable would do the job. But it should be quick! Nobody wants to sit for disk checking for 3-4 hours after a quick 30 min data burn!

I am looking for such a utility on Windows or Linux. Even scripts (python, etc) will do. I just want to be assured that the data is safe.

Can someone help me in this?

Thanks.

share|improve this question
    
Not directly an answer, but have you considered DVD-RAM as backup medium. They are designed for that (in terms of "how long can I store them withour losing the data") and the writer will check that the data is written correctly while it's writing. So no need for a separate cycle afterwards. –  Joey Dec 5 '09 at 12:09
    
Nero has a "verification" process you can optionally use after burning DVDs. –  Breakthrough Dec 7 '09 at 2:15
add comment

1 Answer

up vote 1 down vote accepted

I add a textfile containing MD5 hashes of all files on the disc. I use Cygwin and bash for the basic tools, but they're also available in standalone Windows versions. Here's the process:

  1. Create a folder containing the files I want to burn, e.g. at X:\DVD-Backup-1.

  2. In a Cygwin terminal, find all files in the set to be burned, calculate an MD5 hash for each, and store it into the file:

    # cd into your backup directory
    $ cd /cygdrive/x/DVD-Backup-1
    
    
    # create the sums file outside CWD so it won't be summed as well
    $ find . -type f -print0 | xargs -0 md5sum >> ../dvd-backup-1.md5.txt
    
    
    # don't forget to move the sums file into CWD so it'll be burned too
    $ mv ../dvd-backup-1.md5.txt .
    
  3. Burn the contents of X:\DVD-Backup-1 to DVD with whatever data-burning tool you prefer.

  4. Verify the contents were burned correctly:

    # cd into the DVD drive 
    $ cd /cygdrive/y
    
    
    # run this to get a printout of every file and an OK/failed message
    $ md5sum -c < dvd-backup-1.md5.txt
    
    
    # run this for less output -- only prints files that fail
    $ md5sum -c < dvd-backup-1.md5.txt | perl -lne 'print if not /OK$/'
    

You can substitute sha1sum or sha256sum for md5sum in the above process if you'd prefer using the SHA-1 or SHA-256 hashing algorithms.

share|improve this answer
    
Thankyou ~quack verymuch... if superuser had allowed me... i would have upvoted 100 times for this one.. :) awsome reply!! –  ashishsony Dec 7 '09 at 18:51
    
and i love the soln more because its linux based.. :) and linux is fast.. –  ashishsony Dec 7 '09 at 18:54
add comment

Your Answer

 
discard

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.