How to recover data from a defective CDROM

[Gene Heskett]

On Wednesday 20 May 2009, Jonathan Ryshpan wrote:
>My computer is no longer able to read a CDROM with some fairly valuable
>data.  I have been able to read this CDROM successfully in the past.
>
>Inserting the CDROM into the drive produces this in /var/log/message:
>
>May 20 14:31:05 localhost kernel: sr 2:0:0:0: [sr0] Result: hostbyte=DID_OK
> driverbyte=DRIVER_SENSE,SUGGEST_OK May 20 14:31:05 localhost kernel: sr
> 2:0:0:0: [sr0] Sense Key : Hardware Error [current] May 20 14:31:05
> localhost kernel: sr 2:0:0:0: [sr0] Add. Sense: Timeout on logical unit May
> 20 14:31:05 localhost kernel: end_request: I/O error, dev sr0, sector 0 May
> 20 14:31:05 localhost kernel: __ratelimit: 10 callbacks suppressed May 20
> 14:31:05 localhost kernel: Buffer I/O error on device sr0, logical block 0
> May 20 14:33:02 localhost kernel: sr 2:0:0:0: [sr0] Result: hostbyte=DID_OK
> driverbyte=DRIVER_SENSE,SUGGEST_OK May 20 14:33:02 localhost kernel: sr
> 2:0:0:0: [sr0] Sense Key : Hardware Error [current] May 20 14:33:02
> localhost kernel: sr 2:0:0:0: [sr0] Add. Sense: Timeout on logical unit May
> 20 14:33:02 localhost kernel: end_request: I/O error, dev sr0, sector 0 May
> 20 14:33:02 localhost kernel: Buffer I/O error on device sr0, logical block
> 0 May 20 14:33:02 localhost kernel: Buffer I/O error on device sr0, logical
> block 1 May 20 14:33:02 localhost kernel: Buffer I/O error on device sr0,
> logical block 2 May 20 14:33:02 localhost kernel: Buffer I/O error on
> device sr0, logical block 3
>
>An attempt to get some data using cat fails:
># cat /dev/sr0
>cat: /dev/sr0: Input/output error
>
>Thanks - jon

Can this drive still read other cd's?  Also, if the cd really is scratched, 
there are treatments to restore them at your local Wally World I believe.  In 
a one time pinch, you could use a century old darkroom technique we used for 
scratched negatives since long before my time, rub a bit of the grease from 
the side of your nose into the scratch.

But I'd almost bet a new drive would read it as it is.

-- 
Cheers, Gene
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