[lug] dd vs. cdrecord

[Tkil]

>>>>> "SCDM" == deedsmis  <SoloCDM> writes:

SCDM> Is it possible to use dd to burn a CD without using cdrecord?

If you are just cloning a data CD, you can use just dd:

   dd if=/dev/cd0 of=my-image.iso

If you want to put an arbitrary tree of files onto a CD, you do have
to create an ISO filesystem, so you do have to use mkisofs or similar.

(Ok, that's a bit of a fib -- most modern operating systems also
understand "UDF", which is an evolution of the ISO-9660 format [I
think].)

SCDM> Does an iso need to be made first when using dd?  

See above: if you're just cloning, you can use 'dd' to extract an ISO
image from an existing data CD-ROM, then use 'cdrecord' to burn it to
a blank CD-R.  

If you're burning an arbitrary tree, you have to use 'mkisofs',
although modern computers should have enough cpu, memory, and
bandwidth to do much of the 'mkisofs' work on the fly.  This is a mode
that is supported by some tools, where the output from 'mkisofs' is
fed directly into 'cdrecord' through a pipe, without creating an image
file first.  This is perhaps more convenient, but you lose the chance
to mount the image over loopback and do a quick QA before burning it
permanently.

SCDM> What would the dd syntax be to go from the directory to the CD
SCDM> or from the iso to the CD, whichever is the most appropriate?

See above: you can't really do this.  'dd' just moves data around;
when you go from "directory" to "cd", you need to impose some
structure.  ISO-9660 (and its derivatives, Rock Ridge, Joliet, and
maybe UDF) is the format that readers expect that structure to be in.
'mkisofs' is the most common utility used to create that structure.

t.