verifying md5 of dvd iso burn

[cocoa117]

I had exact same problem, after I burn the dvd, i always use
md5sum /dev/cdrom
to verify the image, and it never the same. What's the solution here?

[rio2000]

i have same problem

so what the solution?

[HappyFeet]

i have same problem

so what the solution?

What app are you using to burn?

[rio2000]

What app are you using to burn?

i am using k3b (and also brasero)

i have no problem when verify CD iso, but i always fail verify dvd iso

[r_avital]

FWIW...

1. Downloaded Karmic amd-64 iso (bittorent/Azureus).
2. Launched k3b, allowed it to generate md5sum. Result matches the md5sum posted on the Ubuntu releases web site. So far so good.
3. Burned on fresh, blank, DVD-R media, after checking the "verify" option. Successful.
4. Verification comes back with an error.
5. In terminal, entered:

   md5sum /dev/dvdrw3

   The generated md5sum was: a4e4558cf95928b20e1ca1ec7e9d9229
6. This does not match the DVD Hash posted on https://help.ubuntu.com/community/UbuntuHashes , which is:

   dc51c1d7e3e173dcab4e0b9ad2be2bbf ubuntu-9.10-desktop-amd64.iso

   Could this be because we're comparing a burned dvd with a compressed ISO? This seems to be what everyone else on this thread is reporting.

However:
I entered the following in a terminal (in the /media/Ubuntu 9.10 amd64 directory, which is where the burned DVD is mounted):

md5sum -c md5sum.txt | grep -v "OK$"

This generates an md5sum hash of each and every file on the DVD and compares them to the hash values in the file named md5sum.txt on the same DVD, and will output all the non-matching file names. No output was generated, so I must conclude that the burning was successful and accurate.

Am I incorrect in any of the above?

If I'm correct that all the files on the CD/DVD are ok, then the instructions posted in the "Check the CD" section at https://help.ubuntu.com/community/HowToMD5SUM are incorrect, as they lead you to check your burned CD/DVD, meaning a decompressed/un-archived collection of files against an ISO archive.