Incorrect md5 sum after burninig ISO

You can report problems, make suggestions, about the new BETA versions in this forum. For stuff related to final releases, please post a message in other forums
Post Reply
kfgz
Posts: 69
Joined: 02 Mar 2008, 18:00

Incorrect md5 sum after burninig ISO

Post by kfgz » 31 May 2010, 18:40

Hi,

The title says it all ;) After burning toooo many CD-RWs I was begining to think WTF ;) : is it my dvd burner fault or maybe it's medium fault? Then I remeber that with 1.5.5 beta new feature showed up:

Code: Select all

The ISO image is now hybrid so it can be copied to an usb stick using dd
Md5 sum of 1.5.4 is OK.

EDIT:

François, If you use

Code: Select all

isohybrid sysrccd.iso


after ISO is created, IMHO everything should be fine.

kfgz
Posts: 69
Joined: 02 Mar 2008, 18:00

Re: Incorrect md5 sum after burninig ISO

Post by kfgz » 01 Jun 2010, 10:28

This bug is still present in 1.5.6-beta1.

admin
Site Admin
Posts: 2715
Joined: 17 Jul 2003, 09:44

Re: Incorrect md5 sum after burninig ISO

Post by admin » 01 Jun 2010, 11:19

Sorry, I don't see what the problem is. The md5sum is generated after the ISO is processed by isohybrid, and the md5sum of the ISO image corresponds to the md5 sum on the website, so what's wrong ?

kfgz
Posts: 69
Joined: 02 Mar 2008, 18:00

Re: Incorrect md5 sum after burninig ISO

Post by kfgz » 01 Jun 2010, 11:38

admin wrote:Sorry, I don't see what the problem is. The md5sum is generated after the ISO is processed by isohybrid, and the md5sum of the ISO image corresponds to the md5 sum on the website, so what's wrong ?
md5sum_of_isohybrid_iso_image != md5sum_of_burned_CD. That might be a problem if your hardware has a failure. Then you are not sure if the burned CD is OK, because md5sums are incorrect even if hardware or CD media is OK.

gernot
Posts: 1130
Joined: 07 Apr 2010, 16:19

Re: Incorrect md5 sum after burninig ISO

Post by gernot » 01 Jun 2010, 14:50

To make sure all data is readable CD-burnig software pads some Blocks after the ISO-image. This blocks makes the checksum wrong.

I tried isoinfo -d -i /dev/scd0 , but this gives also the wrong size and is also incorrect.

Gernot

admin
Site Admin
Posts: 2715
Joined: 17 Jul 2003, 09:44

Re: Incorrect md5 sum after burninig ISO

Post by admin » 01 Jun 2010, 16:07

So you just have to check the md5 sum before you burn the image. There is a binary for windows.
I think it makes more sense to publish the checksum we get on the ISO image because most users check it before they burn it.

Post Reply