can't detect cdrom

[drg55]

I have had knoppix 3.3 and lin4astro (morphix) all working well on hd, but with 3.4 it can't find the cdrom when I click the desktop icon, or try to mount from the command line. This is using knoppix-installer in sbin as beginner.

I notice there is a dvd in mnt not cdrom, so tried

mount -t iso9660 /dev/hdc /mnt/dvd

and it said wrong fs type etc.

Has anyone else had this problem? I tried editing the knx-hdinstall from morphix and it installed but the templates caused an init scripts problem. on boot so I didn't get to find out if it worked.

David.

[drg55]

I hacked a solution to this, by editing /etc/fstab I put in an entry for cdrom (it had dvd) and that seems to have fixed it.

[rrfish72]

This is what my fstab is:

# /etc/fstab: filesystem table.
#
# filesystem mountpoint type options dump pass
/dev/hda3 / ext3 defaults,errors=remount-ro 0 1

proc /proc proc defaults 0 0
/dev/fd0 /floppy vfat defaults,user,noauto,showexec,umask=022 0 0
usbdevfs /proc/bus/usb usbdevfs defaults 0 0
sysfs /sys sysfs defaults 0 0
/dev/cdrom /cdrom iso9660 defaults,ro,user,noexec,noauto 0 0
/dev/cdrom1 /cdrom1 iso9660 defaults,ro,user,noexec,noauto 0 0
/dev/dvd /dvd iso9660 defaults,ro,user,noexec,noauto 0 0
/dev/cdaudio /cdaudio iso9660 defaults,ro,user,noexec,noauto 0 0
/dev/cdrom1 /mnt/auto/cdrom1 auto users,noauto,exec,ro 0 0
# Added by KNOPPIX
/dev/hda1 /mnt/hda1 ntfs noauto,users,exec,ro,umask=000 0 0
# Added by KNOPPIX
/dev/hda5 /mnt/hda5 ntfs noauto,users,exec,ro,umask=000 0 0

What do I need to change to get my cdrom and dvdrom to work?
And ZIP drive and floppy for that matter?

[drg55]

I am still finding its flakey. What I did was change "user" to "users" and deleted "noexec". It seemed to work on the next reboot and then not after that.

Also if I put a music cd in, I couldn't manage to mount it but surprise, if I started the play music cd pgm on the menu, that worked.

Just out of interest what system are you running on. Mine is an Athlon 1gz on a Gigabyte GA-7IXE4 Motherboard. As not too many others seem to have this problem maybe its a hardware glitch. However I did have 3.3 working nicely on the hd.

Warning, I am self taught and I recommend reading "man fstab" (enter this at a command line) first, I have just glossed over it.

David.

[Markus]

Audio CD's don't have a filesystem, so you can't mount them. You have to mount a data CD in order to browse it.
You can check how to build the fstab with:
dmesg|grep CD
dmesg|grep sr
dmesg|grep scd
dmesg|grep hdc
One of them should return something like:
markus@mrk-fujibox:~$ dmesg|grep hdc
ide1: BM-DMA at 0xb808-0xb80f, BIOS settings: hdcMA, hddMA
hdc: TDK CDRW241040B, ATAPI CD/DVD-ROM drive
hdc: attached ide-cdrom driver.
hdc: ATAPI 40X CD-ROM CD-R/RW drive, 2048kB Cache, UDMA(33)

And so the line in fstab would be:
/dev/hdc /cdrom iso9660 defaults,ro,users,noexec,noauto 0 0

[drg55]

actually I have had this problem previiously and "fixed it" by using a different installer, as the installers do the same thing maybe there is a glitch in my machine.

What is sr? I got this output.

drg@Tbird:~$ dmesg|grep sr
end_request: I/O error, dev sr0, sector 0
Buffer I/O error on device sr0, logical block 0
Buffer I/O error on device sr0, logical block 1
Buffer I/O error on device sr0, logical block 2
Buffer I/O error on device sr0, logical block 3
Buffer I/O error on device sr0, logical block 4
Buffer I/O error on device sr0, logical block 5
Buffer I/O error on device sr0, logical block 6
Buffer I/O error on device sr0, logical block 7
Buffer I/O error on device sr0, logical block 8
Buffer I/O error on device sr0, logical block 9
Buffer I/O error on device sr0, logical block 10
Buffer I/O error on device sr0, logical block 11
Buffer I/O error on device sr0, logical block 12
Buffer I/O error on device sr0, logical block 13
Buffer I/O error on device sr0, logical block 14
Buffer I/O error on device sr0, logical block 15
Buffer I/O error on device sr0, logical block 16
Buffer I/O error on device sr0, logical block 17
Buffer I/O error on device sr0, logical block 18
Buffer I/O error on device sr0, logical block 19
Buffer I/O error on device sr0, logical block 20
Buffer I/O error on device sr0, logical block 21
Buffer I/O error on device sr0, logical block 22
Buffer I/O error on device sr0, logical block 23
Buffer I/O error on device sr0, logical block 24
Buffer I/O error on device sr0, logical block 25
Buffer I/O error on device sr0, logical block 26
Buffer I/O error on device sr0, logical block 27
Buffer I/O error on device sr0, logical block 28
Buffer I/O error on device sr0, logical block 29
Buffer I/O error on device sr0, logical block 30
Buffer I/O error on device sr0, logical block 31
end_request: I/O error, dev sr0, sector 0
Buffer I/O error on device sr0, logical block 0
Buffer I/O error on device sr0, logical block 1
end_request: I/O error, dev sr0, sector 0
Buffer I/O error on device sr0, logical block 0
Buffer I/O error on device sr0, logical block 1
Buffer I/O error on device sr0, logical block 2
Buffer I/O error on device sr0, logical block 3
Buffer I/O error on device sr0, logical block 4
Buffer I/O error on device sr0, logical block 5
Buffer I/O error on device sr0, logical block 6
Buffer I/O error on device sr0, logical block 7
Buffer I/O error on device sr0, logical block 8
Buffer I/O error on device sr0, logical block 9
Buffer I/O error on device sr0, logical block 10
Buffer I/O error on device sr0, logical block 11
Buffer I/O error on device sr0, logical block 12
Buffer I/O error on device sr0, logical block 13
Buffer I/O error on device sr0, logical block 14
Buffer I/O error on device sr0, logical block 15
Buffer I/O error on device sr0, logical block 16
Buffer I/O error on device sr0, logical block 17
Buffer I/O error on device sr0, logical block 18
Buffer I/O error on device sr0, logical block 19
Buffer I/O error on device sr0, logical block 20
Buffer I/O error on device sr0, logical block 21
Buffer I/O error on device sr0, logical block 22
Buffer I/O error on device sr0, logical block 23
Buffer I/O error on device sr0, logical block 24
Buffer I/O error on device sr0, logical block 25
Buffer I/O error on device sr0, logical block 26
Buffer I/O error on device sr0, logical block 27
Buffer I/O error on device sr0, logical block 28
Buffer I/O error on device sr0, logical block 29
Buffer I/O error on device sr0, logical block 30
Buffer I/O error on device sr0, logical block 31
end_request: I/O error, dev sr0, sector 0
Buffer I/O error on device sr0, logical block 0
Buffer I/O error on device sr0, logical block 1

I got no response on the other items

root@Tbird:/home/drg# dmesg|grep hdc
root@Tbird:/home/drg# dmesg|grep scd
root@Tbird:/home/drg# dmesg|grep dvd
root@Tbird:/home/drg# dmesg|grep cd
root@Tbird:/home/drg# dmesg|grep cdrom

David.

[Gozar]

Are you sure that that is all you get out of:
dmesg|grep sr

Because that don't make any sence. The wery first lines should tell you what device it is.

from my box
[code]
hl@sid:~$ dmesg |grep sr
sr0: scsi3-mmc drive: 6x/48x cd/rw xa/form2 cdda tray
Attached scsi CD-ROM sr0 at scsi0, channel 0, id 0, lun 0
sr1: scsi3-mmc drive: 32x/32x writer cd/rw xa/form2 cdda tray
Attached scsi CD-ROM sr1 at scsi1, channel 0, id 0, lun 0
hl@sid:~$
[/code/]

Try this:
dmesg|grep sr|less

[drg55]

Today i get nothing from dmesg|grep sr and blank couple of pages from dmesg|grep sr|less.

Is this for scsi devices? I don't have any and I had to "knoppix noscsi" in the boot options as otherwise it would hang.

I'm going to get a burner sometime not too far off and that will allow me to run from the cd again and have the dvd working as well.

Regards,

David.

[Markus]

Don't quote me on this while I could be wrong but I believe sr is for scsi emulation needed by the 2.4 kernel. AFAIK 2.6 doesn't need it anymore, although I'm not sure what happens with the noscsi cheatcode. So even if you have no scsi devices they still could get treated as such.

If dmesg is too filled with mysterious messages you can grep from syslog as root:
grep hdc /var/log/syslog |tail
grep CD /var/log/syslog |tail
grep scd /var/log/syslog |tail
grep sr /var/log/syslog |tail

[drg55]

Its working again today, I haven't done anything else. Now I can't umount it, "devise is busy" when it is not, I have killed the konqueror browser and no terminals are active in that directory. Go figure...

There are no entries in dmesg, completely blank.

I was thinking whether having enabled plug and play in the bios has anything to do with it?

I don't like to change this without good reason. I haven't had a problem with other linux installs such as Fedora. I did have to change it in my laptop to get the sound driver to work (CS4237B card). I believe its better if "plug and play" is not enabled, but anyhow the cd is (sort of) working tonight.

I am not sure if my hard drive is on the way out, I have had trouble with the partition table, so possibly it is not loading correctly. Seems to be a minority problem but others have experienced it. Maybe if we can get enough communication we can identify the common factor.

David.