Re: 2.9test9-mm1 and DAO ATAPI cd-burning corrupt

Jens Axboe
2003-11-05T10:02:28Z

On Wed, Nov 05 2003, Prakash K. Cheemplavam wrote:
> Jens Axboe wrote:
> >On Wed, Nov 05 2003, Prakash K. Cheemplavam wrote:
> >
> >>Jens Axboe wrote:
> >>
> >>
> >>>On Mon, Nov 03 2003, Prakash K. Cheemplavam wrote:
> >>>
> >>>
> >>>>Hi,
> >>>>
> >>>>well I am using k3b0.10.1 and either choosing cdrdao or cdrecord in
> >>
> >>DAO mode to burn the cd ends up in non-bit identical copies, wheres ion
> >>TAO (atleast with my 10x CD-RW I tested) the copy succeded. I tried
> >>several times, and always got this issue.
> >>
> >>>>bash-2.05b$ md5sum livecd-2.6_10-23-2003.iso
> >>>>f73f3a74239dfe94b322b85fd14a306e livecd-2.6_10-23-2003.iso
> >>>>
> >>>>TAO:
> >>>>bash-2.05b$ md5sum /dev/cdroms/cdrom1
> >>>>f73f3a74239dfe94b322b85fd14a306e /dev/cdroms/cdrom1
> >>>>
> >>>>DAO:
> >>>>bash-2.05b$ md5sum /dev/cdroms/cdrom1
> >>>>09e7e2a51af4c64685831513fbac18c2 /dev/cdroms/cdrom1
> >>>
> >>>
> >>>
> >>>Could you please try and cmp the two images, finding out how big the
> >>>corrupted chunks are and what kind of data they contain?
> >>
> >>
> >>After some further investigation I found out, that the data is NOT
> >>corrupted, but in a way truncated in DAO mode: When I read out the image
> >>from the CD-RW drive, about 5kbyte are missing at the end (and doing
> >>several burn, it is always the same amount). Strange enough if I read
> >>the DAO burnt disk out by my DVD-ROM, the image can be read out
> >>completely! Can you understand this behaviour? I don't think it is a
> >>problem of my burner, but rather of the atapi driver?
> >
> >
> >Is actual data missing at the end? If yes, I'd say this looks a lot more
> >like a cdrecord problem.
>
> Sorry, I wasn't precise: The data is on the disc, as my DVD-ROM restores
> the full image (md5sum matches), but the CD-RW does not.

You need to use the pad option to record.

--
Jens Axboe