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

Prakash K. Cheemplavam
2003-11-09T10:47:09Z

Jens Axboe wrote:
> On Thu, Nov 06 2003, Prakash K. Cheemplavam wrote:
>
>>Prakash K. Cheemplavam wrote:
>>
>>>bill davidsen wrote:
>>>
>>>
>>>>In article <3FA8CA87.2070201@gmx.de>,
>>>>Prakash K. Cheemplavam <prakashkc@gmx.de> wrote:
>>>>
>>>>| 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.
>>>>
>>>>There is a problem with ide-scsi in 2.6, and rather than fix it someone
>>>>came up with a patch to cdrecord to allow that application to work
>>
>>>b) The writing or reading issue mentioned above. It is a bit hard to
>>>find out, whether cdrecord actually *writes* an incomplete image
>>>(without using -pad), ie. throwing away the last 4096 bytes, which
>>>*only* happens in non-TAO mode. The programme CDRDAO shows the same
>>>behaviour. Strange enough reading this DAO written image out with my
>>>DVD-ROM makes this (missing?) 4096 bytes reappear... Well, maybe I
>>>should patch the image and put some other bytes instead of the 00s at
>>>the end to see, whether it is a write issue, a read issue of the writer
>>>or a read issue of the reader. Anyway, it doesn't sound right to me,
>>>what is happening at the moment...
>>
>>So tested further: I patched the very last byts of the image and these
>>are my findings:
>>
>>In DAO mode, the complete image is actually written, but the writer is
>>not able to read it out! The last 4096 bytes are not read. I put the
>>CD-RW into my DVD-ROM, and it reads it out completely.
>>
>>So: Is cdrecord/cdrdao making something wrong (yes, I know I can use
>>-pad, but I want an *identical copy*) or has the kernel ATAPI reading
>>routine a bug? (Or has my drive a bug???? Well, I need to read the disc
>>out in windows I guess...)
>
>
> See one of my mails from a few days ago. It's a hardware issue, some
> drives need a bit of pad at the end.

Yup, I verified it in windows. Same issue, so it is a hardware and not
software issue.

Prakash

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