Re: Using cd9660

[adr <adr%sdf.org@localhost>]

On Mon, 27 Jan 2025, Todd Gruhn wrote:

> Date: Mon, 27 Jan 2025 18:54:58 -0500
> From: Todd Gruhn <tgruhn2%gmail.com@localhost>
> To: Mike Pumford <mpumford%mudcovered.org.uk@localhost>
> Cc: Netbsd-Users-List <netbsd-users%netbsd.org@localhost>
> Subject: Re: Using cd9660
>
> I have CD-RW disks that I mount using
> mount -t cd9660  ...
>
> Is there something I cant coppy from this CD-RW to another CD-RW ??
>
> On Mon, Jan 27, 2025 at 5:49 PM Mike Pumford <mpumford%mudcovered.org.uk@localhost> wrote:
> > On 27/01/2025 21:52, Todd Gruhn wrote:
> > > I wrote it to a CD-RW.
> > >
> > > But I can't  cd to /cdrom and delete stuff (or copy to).
> > > What did I miss here... ?
> > >
> > >
> > > I used:
> > >
> > >    mkisofs -o FOO.iso -l -J -R -allow-leading-dots FOO
> > >
> > >    cdrecord -v -ignsize -multi -data speed=4 dev=31,0,0 FOO.iso
> >
> > UDF is writable on CD-RW and DVD-RW. ISO9660 is write once. To rewrite a
> > CD-RW containing an ISO9660 filesystem you have to erase it and rewrite
> > a complete new image.
> >
> > You can leave an ISO9660 disk open which allows writing but old data is
> > then masked not overwritten if you change it so you don't reclaim the space.
> >
> > Mike

I remember using rewritable cd/dvds back in the Pleistocene... with
linux. For cd-rw and dvd-rw a special devices were used to achieve
random access writing, but that was very crappy. DVD-RAM could do
random access writing without these devices and yes, you needed udf
(ueftools?).

I know what you wan to do Todd, and I don't recommend it. My advice:
backup everything you have on those discs and use sd cards if you
want to have separated small storage devices (and maintain backups
for those too). Oh, and don't go cheap with sd cards (they are
already cheap enough) if you don't want surprisses (like the ones
you'll have with those *-rw once they wear out)

Regards.
adr