md5sum problem on reading CD's

[Jason Pyeron]

try

head -c SIZE /dev/scd0 | md5sum

if still broken

what is wc /dev/scd0


On Wed, 12 Oct 2005, Corinna Vinschen wrote:

> On Oct 11 22:03, Stilianos Kesisoglou wrote:
>> Hi,
>>
>> I've discovered an error in using the md5sum command
>> to create a hash for a CD.
>>
>> I was trying to burn a CD, from an ISO image of the
>> Solaris CD1 that I downloaded from Sun's Download
>> Center.
>>
>> Before the burning process, I've calculated the md5
>> hash for the ISO image using both Cygwin's md5sum
>> command and ISOBuster's (that allows also to make the
>> hash for 2048 and 2352 bytes/block).
>>
>> For Cygwin's md5sum I used the command:
>>
>>  %> md5sum sol-10-GA-x86-v1-iso.iso
>>
>> The results for the hashes are below:
>>
>> 3838f0e0560b4a1d9dc43a8cf754965a
>> *sol-10-GA-x86-v1-iso.iso (with Cygwin's md5sum)
>> 3838f0e0560b4a1d9dc43a8cf754965a *CD.tao (with
>> ISOBuster - 2048 bytes/block)
>> d1e3c9bbfc16cf0922d94afeeda2e756 *CD.bin (with
>> ISOBuster - 2352 bytes/block)
>>
>> So there is an agreement with for the hash (with the
>> 2048 setting).
>>
>> After burning the CD, I wanted to check the integrity
>> of the burn so I've run again ISOBuster and Cygwin's
>> md5sum.
>>
>> For Cygwin I've used the command:
>>
>>  %> md5sum /dev/scd0
>>
>> and I got the following results:
>>
>> eeba689f88d7a28e4ef54099db5c429c */dev/scd0 (with
>> Cygwin's md5sum)
>> 3838f0e0560b4a1d9dc43a8cf754965a *CD.tao (with
>> ISOBuster - 2048 bytes/block)
>> d1e3c9bbfc16cf0922d94afeeda2e756 *CD.bin (with
>> ISOBuster - 2352 bytes/block)
>
> I guess reading from /dev/scd0 reads all bits from the CD while ISOBuster
> only reads the exact number of bytes burned on CD.
>
> As I said, just a guess,
> Corinna
>
>

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