Unrecognized DVD-RW / DVD-ROM

[slugman]

Hello. First off I'd like to thank everyone for participating in this forum. Its been a great source of information and has served as an invaluable reference in helping solve some of the more intricate problems I've encountered with my first expedition into the linux world.

I am using Slackware 12.2 on a Toshiba A215-S7427. I preformed a full install from the Slack 12.2 DVD. After spending several days of unsuccessfully configuring ndis wrapper for the RTL8187B chipset, I decided to ditch the 2.6.27 stock kernel for the 2.6.29 (first time for everything right?). Worked like a charm and this beast has never been sexier (excluding the ati drivers not compiling correctly but thats a different story for different day).

My problem is I can't seem to determine where my DVD drive is. Bios recognizes it as a Matshita DVD-RAM VJ-85D5. After looking around some of the other related posts, I'd thought I'd give a poke around dmesg, though I was w/o any luck in grep'ing dvd, cdrom, or related terms When I preform cdrecord -scanbus, or lsscsi for example, I only see my internal hard drive. My /etc/fstab seems to not have any related entry for my dvd drive either (quite odd).

I spent the last 8 or so hours trying to come to a solution w/o success. Hopefully a fellow slacker here may be able to point me in the right direction. I recently downloaded the fedora 11 dvd iso and was hoping to create a dvd and test drive it out.. alas I have a windows box still and will have to use that in the meantime.

Note, I had fedora 10 on this machine and was able to create disks just fine! Slackwares much faster though and I want to keep it!
Note2: dmesg mentions something about a "sd 0:0:0:0: Attached scsi generic sg0 type 0" tho methinks this refers to my card reader..

[HROAdmin26]

You can grep the /dev directory and usually find a CD/DVD link.

ls -alh /dev | grep -i cd

But with a newer kernel, it's likely to be /dev/sr0

eject /dev/sr0

If the CD tray pops open, that's it.

[slugman]

Thanks for the quick reply HRO!

Unfortunately, the first command did not return any results. The second command failed to eject as there doesn't seem to exist a sr0 device on my system. I did however try an

eject /dev/sg0

which made a return code 0, but nothing opened...

[HROAdmin26]

No, sg0 is normally the first HDD.

What does sginfo show?

sginfo -l

sginfo -l
/dev/scd0 /dev/sr0 /dev/sda 
/dev/sg0 [=/dev/sda  scsi0 ch=0 id=0 lun=0]
/dev/sg1 [=/dev/scd0  scsi3 ch=0 id=0 lun=0]

[slugman]

..interestingly I did not have that program, though thanks to the slacky.eu repository I was able to grab the sg3_utils package.

sginfo -l
/dev/sda 
/dev/sg0 [=/dev/sda  scsi0 ch=0 id=0 lun=0]

Thats what I got, still no dice. I'm quite confused because it looks like my machines trying to tell me its not there when BIOS says it is! I am about to test my new boot disk in a moment just to make sure! Once again thanks for the quick reply HRO!

[reed9]

Are you using udev and hal?

With those, you don't want an entry in /etc/fstab for the DVD drive.

[HROAdmin26]

..interestingly I did not have that program, though thanks to the slacky.eu repository I was able to grab the sg3_utils package.

sginfo -l
/dev/sda 
/dev/sg0 [=/dev/sda  scsi0 ch=0 id=0 lun=0]

Thats what I got, still no dice. I'm quite confused because it looks like my machines trying to tell me its not there when BIOS says it is! I am about to test my new boot disk in a moment just to make sure! Once again thanks for the quick reply HRO!

That is what it's telling you - that the kernel doesn't see a CD device. Did you compile then new kernel yourself? If so, I would assume that you left out a component you need and/or combined 1-2 modules that are not compatible.

[slugman]

are you using udev and hal?

I believe I am reed9, running a "ps aux | grep hal; ps aux | grep udev" returns the daemons w/ their respective PIDs. Also, why would you want to remove the dvd device from /etc/fstab if these are enabled? I noticed the line for my dvd device on my other (working) slackware box in /etc/fstab was commented out, so I removed the # thinking it was in error.

That is what it's telling you - that the kernel doesn't see a CD device. Did you compile then new kernel yourself? If so, I would assume that you left out a component you need and/or combined 1-2 modules that are not compatible.

I did compile the kernel myself HRO. I believe your answer has merit because I can't think of any other possibility. I booted from the Fedora 11 dvd iso I created last night and ran the disk integrity check w/o any errors--thus ruling out the posibility of a hardware error. I was certainly hoping to not have to compile a new kernel, but I suppose this gives me an excuse to try out the 2.6.30 series.

Are there any particular modules that I should avoid this time around? Whats the bare minimum to get this working from your guys' experience?

[reed9]

I believe I am reed9, running a "ps aux | grep hal; ps aux | grep udev" returns the daemons w/ their respective PIDs. Also, why would you want to remove the dvd device from /etc/fstab if these are enabled? I noticed the line for my dvd device on my other (working) slackware box in /etc/fstab was commented out, so I removed the # thinking it was in error.

I don't know too much about it, but I know fstab sets the device mount point, and options to mount the drive on boot. The HAL daemon takes care of that automatically for devices like USB sticks or CD/DVD drives. I assume there can be conflict if both are trying to.

A lot of what I know comes from the Arch Linux Wiki. Their Beginner's Guide states:

If you plan on using hal to automount media such as DVDs, you may wish to comment out the cdrom and dvd entries in preparation for hal, which will be installed later in this guide.

But it seems you're drive isn't being recognized at a more fundamental level, so maybe recompiling is a better option. Maybe also try running a stock kernel; if that fixes the problem, you can use that configuration as the base for your custom kernel.

[HROAdmin26]

I did compile the kernel myself HRO. I believe your answer has merit because I can't think of any other possibility. I booted from the Fedora 11 dvd iso I created last night and ran the disk integrity check w/o any errors--thus ruling out the posibility of a hardware error. I was certainly hoping to not have to compile a new kernel, but I suppose this gives me an excuse to try out the 2.6.30 series.

Are there any particular modules that I should avoid this time around? Whats the bare minimum to get this working from your guys' experience?

When I compile a kernel that I want to work "just the same" as the kernel I'm replacing, I load the existing .config for the current working kernel - that generally gets me the same settings for the new kernel.

Your current kernel's config is usually located at /boot/config*

Example on an openSuSE machine:

ls -alh /boot/config*
-rw-r--r-- 1 root root 94K 2008-12-04 22:01 /boot/config-2.6.27.7-9-pae