Re: vndconfig vs mount_cd9660

[Thomas Klausner <wiz%NetBSD.org@localhost>]

On Tue, Dec 29, 2020 at 08:02:19AM +0100, Martin Husemann wrote:
> On Mon, Dec 28, 2020 at 10:43:10PM +0100, Thomas Klausner wrote:
> > I wanted to mount an ISO image (on 9.99.77/amd64), so I did, following the guide:
> > 
> > # vnconfig -c vnd0 file.iso
> > # mount -t cd9660 /dev/vnd0a /mnt
> > mount_cd9660: /dev/vnd0a on /mnt: Invalid argument
> 
> May this image contain a UDF file system (instead of ISO9660)?

Yes!

> In that case you need to vnconfig it with a geometry specification,
> so the vnd gets 2048 byte blocks, and then use mount_udf instead of
> mount_cd9660 (I typically use /dev/vnd0d for that, unless something very
> special is going on or it is a Sun image with explicit disklabel).

That did the trick:

# vnconfig vnd0 file.iso  2048/1/1/1
# mount_udf -o ro /dev/vnd0a /mnt                                                                                                                                                      

disklabel was not more usable than before.

Is "2048/1/1/1" reasonable or should different values be used?

I'd like to add a concrete example to vnconfig and mount_udf(8).
 Thomas