Bug 88936

Summary: Checksum for iso-image on CD/DVD differs from ISO file on disk
Product: [Applications] k3b Reporter: Winfrid Tschiedel <Winfrid.Tschiedel>
Component: generalAssignee: Sebastian Trueg <trueg>
Status: RESOLVED NOT A BUG    
Severity: normal    
Priority: NOR    
Version: unspecified   
Target Milestone: ---   
Platform: openSUSE   
OS: Linux   
Latest Commit: Version Fixed In:
Attachments: session for creating DVD from iso-file

Description Winfrid Tschiedel 2004-09-06 13:53:51 UTC 
Version:            (using KDE KDE 3.2.1)
Installed from:    SuSE RPMs
OS:                Linux

If I create from an ISO a CD or DVD 
the checksum after burning ( md5sum /dev/cdrom ) differs
from the checksum of the iso file on disk.

Comparing the files logically shows that the created CD/DVD
is identical to the files within the iso-file.

It looks to me, that your utility strips of nonrelevant bytes at the end of the iso-file. It would be highly appreciated, that
you copy the iso without any change in length to the CD/DVD.

Many thanks in advance,

Winfrid

PS.: Windows Tools like Nero do it correct ! CD/DVDs created e.g. with NERO can be checked easily with md5sum.
Comment 1 Winfrid Tschiedel 2004-09-07 14:07:21 UTC 
Created attachment 7436 [details]
session for creating DVD from iso-file

The originial size of the iso file was	4359987200 bytes.
After writing the iso-image to a DVD, I checked the length of the image on the
DVD ( the size was now	4700372992 ). After this I compared the first
 4359987200 bytes of the DVD image with the file on the disk -
these  4359987200 bytes are identical. So again the request, do not change
the size of the iso file during burning !

Winfrid Tschiedel
Comment 2 Sebastian Trueg 2004-09-14 08:50:22 UTC 
it's the lead-out. checking with md5sum only works with DVD-R (and I think DVD+R). We do not change sizes anywhere. And if the size would be changed it would be a growisofs issue, not k3b.
Comment 3 wirechief 2008-05-08 15:00:04 UTC 
Using verify it gives a error that track one does not compare with the data
being burnt to the cd-r, this is occurring on different distros not just Ubuntu. If I run md5sum /dev/cdrom i get a good md5sum it matches my download.
thus making verify not reliable indicator of success.