Cannot open blank DVDs under 14.04

[Robert Heller]

At Fri, 19 Sep 2014 19:21:57 +1000 "Ubuntu user technical support,  not for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:

> 
> On 09/19/2014 06:07 PM, Colin Law wrote:
> > On 19 September 2014 08:55, Phil <phil_lor at bigpond.com> wrote:
> >> Thank you for reading this.
> >>
> >> I've spent most of the day trying to install Xubuntu on a friend's laptop
> >> that is currently running a very sick version of Vista.
> >>
> >> I have two laptops; one runs Kubuntu 14.04 and the other Xubuntu 14.04 but
> >> neither will detect blank DVDs. They both will open pre-recorded DVDs, so
> >> the drives are not faulty. Both had version 13.04 installed previously and
> >> did detect blank DVDs. So either I have missed something obvious or 14.04 is
> >> the problem.
> >>
> >> My Kubuntu laptop has Vista installed as well and it will detect blank DVDs.
> >> So I installed unetbootin under Windows, which was an exercise in
> >> frustration in itself, but unetbootin does not see my USB DVD drive (the
> >> internal drive is faulty).
> >>
> >> My friend wants to throw the laptop into the bin but I'd like to show that
> >> Linux can save a little bit of landfill. So, can anyone suggest why both of
> >> my DVD drives cannot see a blank disc but can see a pre-recorded disk? One
> >> of the pre-recorded disks was recorded under 13.04 on the same USB disc
> >> drive.
> >
> > What do you see added to the result of running, in a terminal
> > dmesg
> > when you plug in the USB disc and run dmesg again.
> >
> 
> Thanks KW and Colin for your replies, much appreciated.
> 
> Dmesg shows the following:
> 
> [  178.279530] usb 2-3: USB disconnect, device number 3
> [  347.084187] usb 2-3: new high-speed USB device number 5 using ehci-pci
> [  347.221066] usb 2-3: New USB device found, idVendor=0e8d, idProduct=1806
> [  347.221077] usb 2-3: New USB device strings: Mfr=1, Product=2, 
> SerialNumber=3
> [  347.221084] usb 2-3: Product: MT1806
> [  347.221091] usb 2-3: Manufacturer: MediaTek Inc
> [  347.221098] usb 2-3: SerialNumber: R8RZ6GAC600AYT
> [  347.225267] usb-storage 2-3:1.0: USB Mass Storage device detected
> [  347.225543] scsi7 : usb-storage 2-3:1.0
> [  348.234393] scsi 7:0:0:0: CD-ROM            ASUS     SDRW-08D2S-U 
>   F301 PQ: 0 ANSI: 0
> [  348.261948] sr1: scsi3-mmc drive: 24x/24x writer dvd-ram cd/rw 
> xa/form2 cdda tray
> [  348.262239] sr 7:0:0:0: Attached scsi CD-ROM sr1
> [  348.263008] sr 7:0:0:0: Attached scsi generic sg2 type 5
> 
> Is there anything there that points to a problem?
> 
> As I said, I can read pre-recorded discs but not blank discs. Resting 
> the mouse over the status bar USB icon shows "No device available".

What *exactly* do you expect?  A CD/DVD *burner* (which this obviously is) is 
NOT a 'normal' optical drive in the sense that a read-only drive (non-burner) 
is with media in place.  With readable (eg *recorded*) media, it shows up as 
either a ISO-9660 (of UDF) data file system OR a collection of CDDA audio 
tracks (eg an audio CD).  A *blank* CD-R or DVD-R does not show up as 
anything.  An ISO-9660 (of UDF) data file system is handled by the sr and 
iso9660 (or udf) kernel modules.  An audio CD or a *blank* CD-R or DVD-R is 
not ever handled by a specialized kernel module, but instead though the 
*generic* (sg) SCSI device driver by *usermode* programs (eg a media player or 
a program like cdrecord or growiso or wodim).  I believe some of the GUI file 
browser program (like nautlis) have a 'burn cd/dvd' function, that is a 
wrapper (or replacement) for cdrecord or growiso or wodim.

> 

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