Re: Nonreadable (?) DVD and strange console message

[Christian Koch <cfkoch%sdf.lonestar.org@localhost>]

Hi Thomas,

On Thu, Jul 24, 2014 at 01:58:56AM +0000, Thomas Mueller wrote:
> I have a DVD I can't read, so far I've tried with FreeBSD and NetBSD, get the
> message on mounting:
> 
> CD mmc 16, mmc_cur 0x80, mmc_cap 0xd3b
> 
> I mount with 
> 
> mount_cd9660 /dev/cd0a /cdrom  (/dev/cd0 in FreeBSD), run "ls" and get 
> nothing at all.
> 
> But running "mount" by itself shows the DVD mounted on /cdrom .
> 
> Running df shows
> 
> Filesystem    1K-blocks       Used      Avail %Cap Mounted on
> /dev/dk15      13910362    4401974    8812870  33% /
> ptyfs                 1          1          0 100% /dev/pts
> tmpfs           8357564          4    8357560   0% /var/shm
> /dev/dk3      121863804   52260992   59853708  46% /BETA1
> /dev/dk4      142191228    8022048  122793884   6% /home
> /dev/cd0a       1832610    1832610          0 100% /cdrom
> 
> so there seems to be something on the DVD.  This happens in a drive capable of
> reading other DVDs.
> 
> This is the Seagate Business Storage installation-recovery DVD.
> 
> I haven't connected the Seagate Business Storage NAS yet, thought I'd first
> get an overview of the DVD.
> 
> I assume this would be a data DVD rather than a music/movie DVD.
> 
> I read "man mount_cd9660" but saw no hint regarding the console message I saw.
> 
> Tom

Can you confirm that the DVD is readable in _any_ drive? Not just the ones with
your FreeBSD and NetBSD systems?

Are you sure you want /dev/cd0a instead of /dev/cd0d?

Can you confirm that the data on the DVD isn't garbage? Here's a slightly crazy
idea: use dd(1) to copy the data from /dev/rcd0a into a disk image, then mount
it with the help of vnconfig(8). You can also run file(1) on the disk image and
see what it thinks it is.

In my experience, Seagate often does silly stuff, like hiding things. For
example, my "fresh-out-of-the-box" 1TB hard disk from them actually had a bunch
of dotfiles and $hidden-Windows$ stuff on it. So it's worth running "ls -a" in
addition to "ls" as you mentioned. Seagate probably doesn't want you to consume
its data in "irregular" ways, like using NetBSD ;)

-Christian