Re: [gentoo-user] Re: Damaged CD medium

[Joerg Schilling <Joerg.Schilling@fokus.fraunhofer.de>]

Mick <michaelkintzios@gmail.com> wrote:

> > This is an error at the layer above the audio sector. You may try to use:
> > 
> > cdrecord -noerror -edc-corr
>
> I think you meant to say:  
>
> readcd -noerror -edc-corr

You are of course correct.


> This is was I am getting.
>
> # readcd -noerror -edc-corr
> No target specified, trying to find one...
> Using dev=2,0,0.
> Read  speed: 22160 kB/s (CD 125x, DVD 16x, BD  4x).
> Write speed: 22160 kB/s (CD 125x, DVD 16x, BD  4x).
> Capacity: 250000 Blocks = 500000 kBytes = 488 MBytes = 512 prMB
> Sectorsize: 2048 Bytes
> Copy from SCSI (2,0,0) disk to file '/dev/null'
> end:    250000
> readcd: Input/output error. read_cd: scsi sendcmd: no error
> CDB:  BE 00 00 00 00 00 00 00 37 F8 00 00
> status: 0x2 (CHECK CONDITION)
> Sense Bytes: 70 00 05 00 00 00 00 0E 00 00 00 00 64 00 00 00
> Sense Key: 0x5 Illegal Request, Segment 0
> Sense Code: 0x64 Qual 0x00 (illegal mode for this track) Fru 0x0
> Sense flags: Blk 0 (not valid) 
> cmd finished after 0.016s timeout 40s
> readcd: Input/output error. Cannot read source disk
> readcd: Retrying from sector 0.
> .
> readcd: Input/output error. Error on sector 0 not corrected. Total of 1 
> errors.
> readcd: -noerror set, continuing ...
> .
> readcd: Input/output error. Error on sector 1 not corrected. Total of 2 
> errors.
> readcd: -noerror set, continuing ...
> .
> readcd: Input/output error. Error on sector 2 not corrected. Total of 3 
> errors.
> readcd: -noerror set, continuing ...
> .
> readcd: Input/output error. Error on sector 3 not corrected. Total of 4 
> errors.
> readcd: -noerror set, continuing ...
>
>
> The count of errors runs in the thousands, until I cancel the command.

As mentioned, the high level error correction in readcd can only help when the 
drive does not include a decent Reed Solomon implementation in it's firmware.

What you could do is to check other sector ranges to find out whether the hole 
capacity of the CD is unreadable or whether there are readable parts inside. 
Note however that if you come close to the outer edge of the CD (1-2cm) the 
error rate usually increases.

check the sectors= option in the man page...

Jörg

-- 
 EMail:joerg@schily.net                    (home) Jörg Schilling D-13353 Berlin
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