[wellylug] Creating CD's accurately - a solution

[Nigel Walters]

Hi

The problem seems to be the way the CD is written, usually has padding
after the iso image file has been written. cdrecord's default mode is
TAO (track at once.) If one has an iso to write then
DAO (disk at onCe equivalent to SAO I think) seems to write just the
image without padding. 

cdrecord -v -doa dev=0,0,0 image.iso

allows dd to correctly read back the image

dd if=/dev/scd0 of=image.iso 

the resulting image has the correct checksum.

Now if one already has a cd which has padding added then it can be
verified by the line 

dd if=/dev/cdrom | head -c `stat --format=%s original.iso` | md5sum

which just reads back the size of the original image, ignoring
subsequent padding.

Let me know if I have got any of this wrong !!

Thanks to those who helped.

Nigel


-- 
Nigel Walters <nigel.walters at ihug.co.nz>