DVD not being detected mystery

[Clark Smith]

I have several 14.2 systems, and none of them seems to be able to
detect DVDs. That is, when I insert a DVD in the DVD unit, I can see
nothng whatsoever in /var/log/syslog, /var/log/messages, or dmesg in
those systems.

The thing is, I have another system running Debian, which can
detect the DVD without any problems. This is not happening with a
particular DVD alone - I have tried with several, and the outcome is
always the same: my 14.2 systems can't detect them, whereas the Debian
one can't.

I am reasonably certain that it is not the case that all those
DVD units are broken - I can certainly see the light turning on in them
when I insert the DVD, and I can hear the DVD spinning. Which makes me
think it must something to do with the way in which my 14.2 systems are
configured.

I am using 14.2 with all the patches applied, and I am not aware
of any configuration specifics to prevent the DVD unit from working. Do
you guys have any suggestions how to try and diagnose (and fix) this
problem? I have the feeling that I must be missing something obvious
here, but I am at a loss.

[Alexander Grotewohl]

I have several 14.2 systems, and none of them seems to be able to detect
DVDs. That is, when I insert a DVD in the DVD unit, I can see nothng
whatsoever in /var/log/syslog, /var/log/messages, or dmesg in those
systems.
The thing is, I have another system running Debian, which can
detect the DVD without any problems. This is not happening with a
particular DVD alone - I have tried with several, and the outcome is
always the same: my 14.2 systems can't detect them, whereas the Debian
one can't.
I am reasonably certain that it is not the case that all those
DVD units are broken - I can certainly see the light turning on in them
when I insert the DVD, and I can hear the DVD spinning. Which makes me
think it must something to do with the way in which my 14.2 systems are
configured.
I am using 14.2 with all the patches applied, and I am not aware
of any configuration specifics to prevent the DVD unit from working. Do
you guys have any suggestions how to try and diagnose (and fix) this
problem? I have the feeling that I must be missing something obvious
here, but I am at a loss.

Have you tried manually mounting the DVDs ?

I know at least for me when I was using KDE and Dolphin, some of that
stuff was automated / "Just Worked" .. but perhaps that has been broken?

Is your use a part of the group allowed access to the DVD drive (i.e. not
as root) ?

That's all I can think of for now..

Alex

[Jimmy Johnson]

Post by Clark Smith
I have several 14.2 systems, and none of them seems to be able to
detect DVDs. That is, when I insert a DVD in the DVD unit, I can see
nothng whatsoever in /var/log/syslog, /var/log/messages, or dmesg in
those systems.

From https://www.slackbook.org/html/filesystem-structure-mounting.html
/dev/dvd /mnt/dvd iso9660 ro 0 0
I use 'k3b' to mount and umount cd's and dvd's and don't need fstab for
that, but you may need to add a entry for those drives.

[Henrik Carlqvist]

I have several 14.2 systems, and none of them seems to be able to detect
DVDs. That is, when I insert a DVD in the DVD unit, I can see nothng
whatsoever in /var/log/syslog, /var/log/messages, or dmesg in those
systems.
Do you guys have any suggestions how to try and diagnose (and fix) this
problem?

I would start to check if the system is aware that it has a DVD reader.
In the output from dmesg, you should see the DVD reader being detected at
boot. If it was a long time since last reboot, those old line might be
lost from the dmesg command but can still be found in /var/log/dmesg. You
should find lines looking something like this:

[ 3.432517] scsi 0:0:0:0: CD-ROM ASUS BW-16D1HT
3.00 PQ: 0 ANSI: 5
[ 3.457515] sr 0:0:0:0: [sr0] scsi3-mmc drive: 48x/48x writer dvd-ram
cd/rw xa/form2 cdda tray
[ 3.457686] cdrom: Uniform CD-ROM driver Revision: 3.20
[ 3.457818] sr 0:0:0:0: Attached scsi CD-ROM sr0

Another way to see if your system is aware of your DVD reader is to study
the content of /proc/scsi/scsi , on my system it looks like this:

cat /proc/scsi/scsi
Attached devices:
Host: scsi0 Channel: 00 Id: 00 Lun: 00
Vendor: ASUS Model: BW-16D1HT Rev: 3.00
Type: CD-ROM ANSI SCSI revision: 05
Host: scsi1 Channel: 00 Id: 00 Lun: 00
Vendor: ATA Model: ST1000DM010-2EP1 Rev: CC43
Type: Direct-Access ANSI SCSI revision: 05

If your system is aware of your DVD reader I would double check that the
DVDs you insert are really supported. Maybe your are trying to put a DVD
disc in a CDROM reader? Maybe your DVD discs are dual layer and your
drive only supports single layer? Maybe you are putting a DVD+R disc in a
reader which only supports DVD-R?

If your system does not know anything about your DVD reader I would check
that the SATA cable is connected between the DVD reader and the
motherboard. I would also reboot to enter CMOS setup to check that your
motherboard is aware of the DVD reader and that the SATA channel hasn't
been disabled in CMOS setup.

I also have several 14.2 systems and they are all able to detect CDROM,
DVD and some of them BluRay. Depending on configuration the users will
also be able to mount such discs, usually the machines have the following
line in /etc/fstab:

/dev/cdrom /mnt/cdrom auto noauto,user,ro,comment=x-gvfs-show 0 0

However, even without users being able to mount the discs you should be
able to se information about the disc in the output from the command
dmesg. Did you configure your own custom kernel? To be able to use CDROM
and DVD you will need CONFIG_BLK_DEV_SR.

regards Henrik

[Lew Pitcher]

I have several 14.2 systems, and none of them seems to be able to detect
DVDs. That is, when I insert a DVD in the DVD unit, I can see nothng
whatsoever in /var/log/syslog, /var/log/messages, or dmesg in those
systems.

[snip]

I am using 14.2 with all the patches applied, and I am not aware
of any configuration specifics to prevent the DVD unit from working. Do
you guys have any suggestions how to try and diagnose (and fix) this
problem? I have the feeling that I must be missing something obvious
here, but I am at a loss.

I believe that the userland mechanics of cdrom autodetect are handled by
udev. Are you running udevd on your Slackware 14.2 systems?

[Rinaldi]

Post by Lew Pitcher

I have several 14.2 systems, and none of them seems to be able to detect
DVDs. That is, when I insert a DVD in the DVD unit, I can see nothng
whatsoever in /var/log/syslog, /var/log/messages, or dmesg in those
systems.

[snip]

I am using 14.2 with all the patches applied, and I am not aware
of any configuration specifics to prevent the DVD unit from working. Do
you guys have any suggestions how to try and diagnose (and fix) this
problem? I have the feeling that I must be missing something obvious
here, but I am at a loss.

I believe that the userland mechanics of cdrom autodetect are handled by
udev. Are you running udevd on your Slackware 14.2 systems?

I remember in years gone by having to "modprobe sg" to get DVD recognized.

Rinaldi

[Clark Smith]

Thanks everybody for your suggestions. Two 14.2 systems are
definitely affected, and I don't know why. The DVD device is correctly
detected in both. However, when I insert a DVD neither system is able to
detect it: when I try to mount it, in both cases I get a diagnostic to
the effect that no media is found.

Since, contrary to what I thought, other 14.2 systems do not have
any problems with the DVDs I was trying to read, I am guessing that
something must be borked in the DVD units in those two systems.

[Henrik Carlqvist]

Thanks everybody for your suggestions. Two 14.2 systems are definitely
affected, and I don't know why. The DVD device is correctly detected in
when I try to mount it, in both cases I get a diagnostic to the effect
that no media is found.
Since, contrary to what I thought, other 14.2 systems do not have
any problems with the DVDs I was trying to read, I am guessing that
something must be borked in the DVD units in those two systems.

What about CDROM? Are you able to read such discs?

regards Henrik

[Clark Smith]

Post by Henrik Carlqvist

Thanks everybody for your suggestions. Two 14.2 systems are definitely
affected, and I don't know why. The DVD device is correctly detected in
when I try to mount it, in both cases I get a diagnostic to the effect
that no media is found.
Since, contrary to what I thought, other 14.2 systems do not have
any problems with the DVDs I was trying to read, I am guessing that
something must be borked in the DVD units in those two systems.

What about CDROM? Are you able to read such discs?

I had to do some digging around, for I got rid of most of my
CDROMs long ago. Anyway, I did find a few, and I can indeed mount them
without any problems using the troublesome DVD units. Notice that those
devices are DVD RW devices. It is still the case that they can't
recognize the medium when insert a DVD in them.

[Henrik Carlqvist]

Notice that those devices are DVD RW devices. It is still the case that
they can't recognize the medium when insert a DVD in them.

Could it be that they are old DVD-RW devices and you try to insert DVD+R
or DVD+RW discs? Have you tried any DVD-R disc?

regards Henrik

[Clark Smith]

Post by Henrik Carlqvist

Notice that those devices are DVD RW devices. It is still the case that
they can't recognize the medium when insert a DVD in them.

Could it be that they are old DVD-RW devices and you try to insert DVD+R
or DVD+RW discs? Have you tried any DVD-R disc?

I'll try to find a DVD-R, if I still have any. The thing is,
those two systems just refuse to recognize even commercial DVDs with pre-
recorded video material - movie DVDs.

Other than this, I used the inxi -Fxd command to obtain
information about the drives, and here's what I am getting in the
offending 14.2 systems:

Optical-1: /dev/sr0 vendor: TSSTcorp model: CDDVDW SH-S223L rev: SB03
dev-links: cdr,cdr0,cdrom,cdrom0,cdrw,cdrw0,dvd,dvd0,dvdr,dvdr0,
dvdrw,dvdrw0,dvdwriter,dvdwriter0
Features: speed: 48 multisession: yes audio: yes dvd: yes
rw: cd-r,cd-rw,dvd-r,dvd-ram state: running

Optical-1: /dev/sr0 vendor: hp model: CDDVDW SH-216BB rev: HE30
dev-links: cdr,cdr0,cdrom,cdrom0,cdrw,cdrw0,dvd,dvd0,dvdr,dvdr0,dvdrw,
dvdrw0,dvdwriter,dvdwriter0
Features: speed: 40 multisession: yes audio: yes dvd: yes
rw: cd-r,cd-rw,dvd-r,dvd-ram state: running

And here is the matching output for a 14.2 system that has no
problems with DVDs:

Optical-1: /dev/sr0 vendor: SONY model: DVD RW DW-D26A rev: JYS2
dev-links: cdr,cdr0,cdrom,cdrom0,cdrw,cdrw0,dvd,dvd0,dvdr,dvdr0,
dvdrw,dvdrw0,dvdwriter,dvdwriter0
Features: speed: 48 multisession: yes audio: yes dvd: yes
rw: cd-r,cd-rw,dvd-r state: running

[root]

Post by Clark Smith
Other than this, I used the inxi -Fxd command to obtain
information about the drives, and here's what I am getting in the
Optical-1: /dev/sr0 vendor: TSSTcorp model: CDDVDW SH-S223L rev: SB03
dev-links: cdr,cdr0,cdrom,cdrom0,cdrw,cdrw0,dvd,dvd0,dvdr,dvdr0,
dvdrw,dvdrw0,dvdwriter,dvdwriter0
Features: speed: 48 multisession: yes audio: yes dvd: yes
rw: cd-r,cd-rw,dvd-r,dvd-ram state: running
Optical-1: /dev/sr0 vendor: hp model: CDDVDW SH-216BB rev: HE30
dev-links: cdr,cdr0,cdrom,cdrom0,cdrw,cdrw0,dvd,dvd0,dvdr,dvdr0,dvdrw,
dvdrw0,dvdwriter,dvdwriter0
Features: speed: 40 multisession: yes audio: yes dvd: yes
rw: cd-r,cd-rw,dvd-r,dvd-ram state: running
And here is the matching output for a 14.2 system that has no
Optical-1: /dev/sr0 vendor: SONY model: DVD RW DW-D26A rev: JYS2
dev-links: cdr,cdr0,cdrom,cdrom0,cdrw,cdrw0,dvd,dvd0,dvdr,dvdr0,
dvdrw,dvdrw0,dvdwriter,dvdwriter0
Features: speed: 48 multisession: yes audio: yes dvd: yes
rw: cd-r,cd-rw,dvd-r state: running

Try switching the drive between the machines. If the problem sticks
with the drives replace the failed drive.