Does 'dd if=/dev/cd0d' (replace d with c for various platforms)
	work?

-- 
		David/absolute		-- www.netbsd.org: No hype required --


On Wed, 31 Oct 2001, Peter Fairbrother wrote:

> Is there some way to read blocks on a cdrom, eg using dd if=/dev/cd0a etc,
> without unmounting the CD?
>
> I want to read numbered blocks, but as the CD has dd (and root, no HDD) on
> it I can't easily unmount it. Using dd if=/cdrom only reads the first 2k,
> and if I use dd if=/dev/cd0a when mounted I get "device busy".
>
> (It's to verify the contents of the CD by reading random blocks, hashing
> them, and comparing with the result from a known-good CD. I could put dd on
> a mfs, but I'd prefer another solution as this is hard (only a single
> unionfs works, anyone know why?) and needs more memory)
>
> Thanks
>
> -- Peter Fairbrother
>
>