Re: DVD "backup" trouble

[Reco <recoverym4n@enotuniq.net>]

	Hi.

On Sun, Jan 19, 2020 at 06:03:55PM +0100, Thomas Schmitt wrote:
> Reco wrote:
> > xorriso somehow read the DVD contents in full.
> > The question is - what did xorriso done differently?
> 
> It does it by talking nearly directly to the drive. Linux contributes
> its ability to transport SCSI commands and bring back drive replies.
> All other CD-ROM related brain of Linux gets circumvented.

Thanks.

> Another way to inquire the Linux kernel's idea of DVD size is
> 
>   $ lsblk -b -o SIZE -n /dev/sr0
>   4700372992

And the actual culprit was udftools package that was installed for
years (lsblk output):

sr0                            11:0    1   3.9G  0 rom
pktcdvd0                      252:0    1   1.2G  0 disk

Somehow /dev/pktcdvd0 managed to truncate the reads from /dev/sr0.
Blacklisting the offending udev rule ("touch
/etc/udev/rules.d/80-pktsetup.rules") fixed it.

Thank you for the idea.

Reco