Sorry to ask this question which has been asked by dozens of other people, but it seems that though the symptoms may be the same, most people have different issues. I installed Ubuntu 12.10 on my Acer Aspire5100-5023 computer which has its own issues (particularly that there isn't a compatible graphics driver for the onboard video and I'm using openGL, but that's a different story altogether).
The build in dvd-rw doesn't seem to be detected by ubuntu and an external dvd drive, an asus SDR-08B1-U slim dvd reader, doesn't seem to want to mount. It may be malfunctioning hardware, but it seems to unlikely that both should fail. Right now this question will focus on my external usb dvd reader, the asus SDR-08B1-U.
So the output of sudo lshw -C disk is
*-disk
description: SCSI Disk
product: 10EACS External
vendor: WD
physical id: 0.0.0
bus info: scsi@2:0.0.0
logical name: /dev/sda
version: 1.65
serial: WD-WCAU40146829
size: 931GiB (1TB)
capabilities: partitioned partitioned:dos
configuration: ansiversion=4 sectorsize=512 signature=44fdfe06
*-disk
description: SCSI Disk
physical id: 0.0.0
bus info: scsi@5:0.0.0
logical name: /dev/sdb
size: 14GiB (15GB)
capabilities: partitioned partitioned:dos
configuration: sectorsize=512 signature=c3072e18
*-disk
description: SCSI Disk
physical id: 0.0.0
bus info: scsi@6:0.0.0
logical name: /dev/sdc
size: 7441MiB (7803MB)
capabilities: partitioned partitioned:dos
configuration: sectorsize=512 signature=c3072e18
*-cdrom
description: DVD reader
product: SDR-08B1-U
vendor: ASUS
physical id: 0.0.0
bus info: scsi@7:0.0.0
logical name: /dev/cdrom
logical name: /dev/dvd
logical name: /dev/sr0
version: 1.00
capabilities: removable audio dvd
configuration: status=busy
I tried to mount the drive manually by creating a directory /media/myusername/cdrom0 and typing in
sudo mount /dev/sr0 /media/myusername/cdrom0
but that results in
mount: /dev/sr0 already mounted or /media/myusername/cdrom0 busy
so then I tried
umount /dev/sr0
which returns
umount: /dev/sr0 is not mounted (according to mtab)
The drive is making sounds as if it is restarting itself constantly. The light indicating that it is operating is on. Now, previously when I used it with windows, it seemed to work, however, since then, on boot up, I get a fixed disk error with my harddrive and have been booting Ubuntu from and external usb harddrive since, which works remarkably well! But I can't verify that the drive is working 100%. However, rather than jump to the conclusion "it must be a hardware issue, gtfo" I would appreciate any possible suggestions to see it there is something else I can do. Alternatively, I'm opened to suggestions about my built in optical drive. It doesn't even show up when I use lshw but the drive does light up when I insert media.
So here's the output of dmesg | grep /dev/sr0
[48868.707336] sr0: scsi3-mmc drive: 24x/24x cd/rw xa/form2 cdda pop-up
[48868.707807] sr 5:0:0:0: Attached scsi CD-ROM sr0
Okay, so I looked around other questions and online forums for people with similar issues. Here's one command used to get information, though I'm not quite sure what the command actually does or what the information reflects. Sorry, I'm not an expert. Running wodim --prcap dev=/dev/sr0 returns
wodim: Operation not permitted. Warning: Cannot raise RLIMIT_MEMLOCK limits.
Device type : Removable CD-ROM
Version : 0
Response Format: 2
Capabilities :
Vendor_info : 'ASUS '
Identification : 'SDR-08B1-U '
Revision : '1.00'
Device seems to be: Generic mmc2 DVD-ROM.
Drive capabilities, per MMC-3 page 2A:
Does read CD-R media
Does not write CD-R media
Does read CD-RW media
Does not write CD-RW media
Does read DVD-ROM media
Does read DVD-R media
Does not write DVD-R media
Does not read DVD-RAM media
Does not write DVD-RAM media
Does not support test writing
Does read Mode 2 Form 1 blocks
Does read Mode 2 Form 2 blocks
Does read digital audio blocks
Does restart non-streamed digital audio reads accurately
Does not support Buffer-Underrun-Free recording
Does read multi-session CDs
Does read fixed-packet CD media using Method 2
Does not read CD bar code
Does read R-W subcode information
Does not return R-W subcode de-interleaved and error-corrected
Does read raw P-W subcode data from lead in
Does return CD media catalog number
Does return CD ISRC information
Does support C2 error pointers
Does not deliver composite A/V data
Does play audio CDs
Number of volume control levels: 256
Does support individual volume control setting for each channel
Does support independent mute setting for each channel
Does not support digital output on port 1
Does not support digital output on port 2
Loading mechanism type: pop-up
Does not support ejection of CD via START/STOP command
Does not lock media on power up via prevent jumper
Does not allow media to be locked in the drive via PREVENT/ALLOW command
Is not currently in a media-locked state
Does not support changing side of disk
Does not have load-empty-slot-in-changer feature
Does not support Individual Disk Present feature
Maximum read speed: 4233 kB/s (CD 24x, DVD 3x)
Current read speed: 4234 kB/s (CD 24x, DVD 3x)
Maximum write speed: 0 kB/s (CD 0x, DVD 0x)
Current write speed: 0 kB/s (CD 0x, DVD 0x)
Rotational control selected: CLV/PCAV
Buffer size in KB: 198
Copy management revision supported: 1
Number of supported write speeds: 0
CONFIRMED: A friend tested this drive on a netbook running windows 7 and it was able to run a dvd (starcraft 2 if anyone cares) without issues. Windows was able to access the drive without any drivers, just plug n play. So there is not an hardware issue/defect. Again, it sounds as though the drive restarts every few seconds when I plug it into Ubuntu 12.10. So the question is whether this is a bug or something else that can be fixed.
And here's the product spec page http://usa.asus.com/Optical_Storage/External_Slim_DVD_Drive/SDR08B1U/#specifications
