ISO file Hash value mismatch.

[cvmanjoo]

Hi, friends this is my first post.

 

Well I had a iso file and Hashed with SHA-1 I noted that value,

and burned that ISO to DVD..

 

But after few days I Read that to DVD to ISO file.

Now this new SHA-1 hash is not matching to the old value.

 

So where i gone wrong?

 

Note: There is not even a light scratch on the DVD.

 

is there any some settings or something?

 

Thank you All

[LIGHTNING UK!]

Did you burn it to a DVD+ format disc?

 

If the image size wasn't already a multiple of 16 sectors, it will be now - and that's where the MD5 / SHA-1 will go wrong.

[cvmanjoo]

Yes I burned that to DVD+R, So is that wrong?

Should i use DVD-R. ?

[cvmanjoo]

Guess I lost original ISO file.

 

 

So Whats the procedure to retain the same iso file in future DVD Burn and reading.?

[LIGHTNING UK!]

Everything up until the end of the original ISO will be exactly the same... so you haven't really 'lost' anything.

 

When burning to DVD+ format discs the drive just pads the end (with zeros) so it's a multiple of 16 sectors (1 ECC block). So at most it will have added 15 sectors worth of zeros (15 * 2048 bytes).

 

Even if you went back to the original ISO, it would still end up the same the next time you burnt it (to a DVD+ disc).

 

I don't know what kind of ISO it is that you're burning (what it contains), but is it really a deal breaker if it's larger?

 

When ImgBurn 'builds' ISO files it always makes their size a multiple of 16 sectors for this very reason.

[cvmanjoo]

I don't know what kind of ISO it is that you're burning (what it contains),

Its a Movie in a DVD or DVD DL's ISO.

 

We have private torrent site to share movies of my local language.

Where sometimes we share DVD5 and DVD9 ISO's over private torrent.

After Downloading i used to burn them to DVD's and watch it on my DVD-Player,

 

The problem occurs when i need to reseed that torrent.

It is recommended me from administrator to seed the same torrent instead of creating new one.

If its avi or any other media file no problem.

the problem occurs with the ISO.

 

Guess I Cleared to you.

[LIGHTNING UK!]

Ok well I guess you can try an image that isn't a multiple of 16 sectors and see if your drive also pads DVD-R to that level.

 

If it doesn't then you're ok.

 

If it does then you're stuck! You'd have to record the original ISO length in a document and manually trim it after reading the disc back to a new ISO.

[cvmanjoo]

Hmmm

 

manually trim it after reading the disc back to a new ISO.

 

fine, Get me one simple tool to trim that extra bytes

[LIGHTNING UK!]

Any hex editor will do.

[cvmanjoo]

Suggest me ur favorite free Hex Editor.

Not all editor will allow to edit those huge files.