Subject: Re: Multisession CD-ROMs
To: None <current-users@NetBSD.ORG>
From: Ty Sarna <tsarna@endicor.com>
List: current-users
Date: 04/18/1996 22:49:12
In article <199604161543.LAA28393@ginger.cmf.nrl.navy.mil>,
Ken Hornstein  <kenh@cmf.nrl.navy.mil> wrote:
> >when you are at it perhaps you can find out how to read multivolume cds too.
> >Dont ask me what it is but our software (gear) allows to make cds in
> >this format. With it it seems you can burn several cds in one without
> >reading the filetree and produce a new filetree image.
> >I made such a CD once but was not able to read it with any OS yet.
> 
> Ummm, I was under the impression that's what multisession cd's are, but
> hey, what do I know? :-)  If you find a reference to more info on this,
> just let me know.

I think they're the logical inverses of each other, actually...  A
multisession CD is multiple filesystems (or other data) on a single CD,
while a multivolume CD9660 filesystem is a single fs that spans two or
more CDs (vaguely like a ccd, but at the FS level rather than the block
level).

AFAIK, this is one of those capabilities that ISO loves to specify, but
that nobody ever implements because it's too much work for something not
that useful. All the ISO specs (networking, X.400, etc) seem to be full
of junk like this. 

(Maybe someone really does use it somewhere, but it's certainly rare)