I need some advice on how to go about troubleshooting a CDROM drive that is not working. It had been working after I first installed Mandrake, now it's not working. Seems to be a driver problem. I get an i/o error when I enter /mnt/cdrom.

My setup is this:
hda - HD
hdb - Internal Zip
hdc - The now not working 24x CDROM (not listed in dmesg)
hdd - working CDRW drive

The CDROM drive is the slave to the CDRW on the secondary IDE. I am using supermount. The terminal tells me that unmount is not a commmand -- I tried to unmount thinking I could then try to remount it.

I could really use some help from a nice person.

Thanks

Your shell is right! As always :-)
It's umount, not unmount!
But this will not solve your main problem. Your cdrom is not detected during boot-time?
Did you change hardware in your PC?
Did you tried to mount "by hand"?

No hardware changes since the install. Here's what I get with the mount command -- notice the device is listed on the last line.

[root@localhost /mnt]# mount
/dev/hda1 on / type ext2 (rw)
none on /proc type proc (rw)
none on /dev/pts type devpts (rw,mode=0620)
/dev/hda6 on /home type ext2 (rw)
/mnt/cdrom2 on /mnt/cdrom2 type supermount (rw,fs=iso9660,dev=/dev/cdrom2)
/mnt/floppy on /mnt/floppy type supermount (rw,fs=vfat,dev=/dev/fd0)
/mnt/zip on /mnt/zip type supermount (rw,fs=vfat,dev=/dev/zip)
/mnt/cdrom on /mnt/cdrom type supermount (rw,fs=iso9660,dev=/dev/cdrom)

Now when I check the drive/mount point:

[root@localhost /mnt]# ls
cdrom/ cdrom2/ disk/ floppy/ zip/
[root@localhost /mnt]# cd cdrom
bash: cd: cdrom: Input/output error

Info form dmesg:

ide0: BM-DMA at 0xd800-0xd807, BIOS settings: hda:DMA, hdb:pio
ide1: BM-DMA at 0xd808-0xd80f, BIOS settings: hdc:DMA, hdd:DMA
hda: Maxtor 72004 AP, ATA DISK drive
hdb: IOMEGA ZIP 100 ATAPI Floppy, ATAPI FLOPPY drive
hdd: Memorex CRW-1622, ATAPI CDROM drive
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
ide1 at 0x170-0x177,0x376 on irq 15
hda: Maxtor 72004 AP, 1916MB w/128kB Cache, CHS=973/64/63
Floppy drive(s): fd0 is 1.44M
FDC 0 is a post-1991 82077
md driver 0.90.0 MAX_MD_DEVS=256, MAX_REAL=12
Now later it says the following -- does this mean that it thinks the CDROM is SCSI?

sr0: CDROM not ready. Make sure there is a disc in the drive.
cdrom: open failed.

Why sr0 ?

Thanks for the help.

Please go into your /dev directory and search for "cdrom". It should be a soft link to /dev/hdc !
What do you see? Is it a link to sr0?

You might also try the following:
insert a CD in the cdrom-drive; then
umount /mnt/cdrom (maybe now you will see some errors)
mount -t iso9660 -o ro /dev/sr0 /mnt/cdrom

First something interesting -- I got a new 8GB HD for linux box (old one was 2.GB :( ). As a result, I reinstalled Mandrake using the CDROM in question. Worked fine. Once the install was completed and I was able to get to a prompt, I tried to access the CDROM (as root) and . . . nothing. I don't get it.

Now, In the /dev directory, I have 3 cdrom related shortcuts --cdrom, cdrom1, and cdrom2. Properites show cdrom one linked to /dev/hdc -- cdrom1 is linked to /dev/scd0 -- cdrom2 is linked to /dev/scd0.

/mnt/cdrom2 is my CDRW and it works. /mnt/cdrom (i assume) is my other CDROM (24x) which is not working. By the way, for what it is worth, HardDrake is showing this CDROM as SCSI for some reason -- it is IDE.

When I goto /dev/mnt/cdrom it lets me into the directory. When I type ls it just returns another prompt -- no message. I typed umount /mnt/cdrom and got no messages, just another prompt. When I typed mount -t iso9660 -o ro /dev/sr0 /mnt/cdrom I got mount: No medium found (but there is a cd in the drive). I tried mount -t iso9660 -o ro /dev/hdc /mnt/cdrom and got mount: /dev/hdc is not a valid block device.

new dmesg - info

ide_setup: hdd=ide-scsi
ide_setup: hdb=ide-floppy

ide0: BM-DMA at 0xd800-0xd807, BIOS settings: hda:DMA, hdb:pio
ide1: BM-DMA at 0xd808-0xd80f, BIOS settings: hdc:DMA, hdd:DMA
hda: Maxtor 90845D4, ATA DISK drive
hdb: IOMEGA ZIP 100 ATAPI Floppy, ATAPI FLOPPY drive
hdd: Memorex CRW-1622, ATAPI CDROM drive
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
ide1 at 0x170-0x177,0x376 on irq 15
hda: Maxtor 90845D4, 8063MB w/512kB Cache, CHS=1027/255/63
Floppy drive(s): fd0 is 1.44M
FDC 0 is a post-1991 82077
scsi : 0 hosts.
scsi : detected total.
scsi0 : SCSI host adapter emulation for IDE ATAPI devices
scsi : 1 host.
Vendor: Memorex Model: CRW-1622 Rev: D4.0
Type: CD-ROM ANSI SCSI revision: 02
Detected scsi CD-ROM sr0 at scsi0, channel 0, id 0, lun 0
sr0: scsi3-mmc drive: 2x/6x writer cd/rw xa/form2 cdda tray
Uniform CDROM driver Revision: 2.56
hdb: 98304kB, 96/64/32 CHS, 4096 kBps, 512 sector size, 2941 rpm
hdb: The drive reports both 100663296 and 0 bytes as its capacity

sr0: CDROM not ready. Make sure there is a disc in the drive.
cdrom: open failed.
sr0: CDROM not ready. Make sure there is a disc in the drive.
cdrom: open failed.
sr0: CDROM not ready. Make sure there is a disc in the drive.
cdrom: open failed.

(spaces indicate skiped items -- these are all the ide/hd/scsi references I found.) Thank You !!!!

harddrake is showing the cdrom OR the cdrw as a scsi-device?
If it is showing the cdrom as a scsi-device, then your fstab-settings are wrong.
Looks to me like your cdrw AND cdrom should be configured as scsi-devices. Btw: You need the scsi-emulation for burning CD's.
Let's find out, what's the correct devicename for your cdrom is. Type the following command and watch the LED on your cdrom-device:
cat /dev/scd0 .../scd1 ..../scd2 and so on.
cat /dev/hdc .../hdc1 ...and so on.
Did you see a short blinking of the LED on the cdrom?
If yes, you have found the correct devicename!

Maybe now we can solve the problem.

Devnull, thanks for your help. Here's what i got.

Found that, yes, /dev/scd0 is the CDRW -- When I type cat /dev/scd0 I get giberish and beeps but the drive light does blink. Again, so far I have been able to access this device with no problem.

cat /dev/scd1 ... scd2 ... etc. gives me "No such device"

cat /dev/hdc gives me cat: /dev/hdc: Device not configured -- same for /dev/hdc1 .. 2 .. etc.

Now, here is what I don't understand. This tells me that the device is not configured, but when I type mount to get the mount information, I get the following:

/dev/hda1 on / type ext2 (rw)
none on /proc type proc (rw)
none on /dev/pts type devpts (rw,mode=0620)
/dev/hda6 on /home type ext2 (rw)
/mnt/cdrom on /mnt/cdrom type supermount (rw,fs=iso9660,dev=/dev/cdrom)
/mnt/cdrom2 on /mnt/cdrom2 type supermount (rw,fs=iso9660,dev=/dev/cdrom2)
/mnt/floppy on /mnt/floppy type supermount (rw,fs=vfat,dev=/dev/fd0)
/mnt/zip on /mnt/zip type supermount (rw,fs=vfat,dev=/dev/zip)
automount(pid423) on /misc type autofs (rw,fd=5,pgrp=423,minproto=2,maxproto=3)


neovox

Oh, one other thing. I just checked Hardrake again. Under cdrom I have a listing for my Memorex CDRW then an entry under that called Unknown. Unknown shows up as Device and Vendor Unknown. Device /dev/scd0 and Bus type SCSI. So, this has to be my CDRW too. Given that, there is no entery for the other CDROM. However, a mount point for that cd is still shown as part of mount. (see output above) Now, I would guess that this does not gurentee that it is associated with the actual CDROM device. Is there a way for me to figure out which device /dev/hd? is associated with the CDROM.

/dev/hda = Main HD
/dev/hdb = IDE Zip Deive
/dev/hdc = ?
/dev/scd0 = CDRW

It's confusing!
Let's resume. /dev/scd0 (/dev/cdrom1 ?!) is your cdrw!
(/dev/cdrom1 is the link to /dev/scd0 ???)
/dev/cdrom (aka /dev/hdc) should be your cdrom-device.

I would like to do the following:
1. backup your /etc/fstab
2. replace the two lines concerning the cdrom/cdrw with the following lines:
/dev/scd0 /mnt/cdrom2 auto user,noauto,nosuid,exec,nodev,ro 0 0

/dev/hdc /mnt/cdrom auto user,noauto,nosuid,exec,nodev,exec,ro 0 0

3. reboot
4. watch the messages at boot-time !
5. now "mount -t iso9660 -o ro /dev/hdc /mnt/cdrom" or just "mount /dev/cdrom"

Another question: What's your kernel-version? Original 2.2.x or an upgrade to 2.4.x?

You might also try the cdrecord-software.
Do an "cdrecord -scanbus" and check if the CDR-devices are identified.

Sorry, but it's hard to do it remotely!

Sorry I did not reply to your post sooner. I had a heck of a week. But here we go again. . .


The following info comes from going to the /dev directory and right clicking on the associated cdrom device and viewing properities:

dev/cdrom points to hdc
dev/cdrom1 points to /dev/scd0
dev/cdrom2 points to scd0


If I type mount at the prompt I get this:

/dev/hda1 on / type ext2 (rw)
none on /proc type proc (rw)
none on /dev/pts type devpts (rw,mode=0620)
/dev/hda6 on /home type ext2 (rw)
/mnt/cdrom on /mnt/cdrom type supermount (rw,fs=iso9660,dev=/dev/cdrom)
/mnt/cdrom2 on /mnt/cdrom2 type supermount (rw,fs=iso9660,dev=/dev/cdrom2)
/mnt/floppy on /mnt/floppy type supermount (rw,fs=vfat,dev=/dev/fd0)
/mnt/zip on /mnt/zip type supermount (rw,fs=vfat,dev=/dev/zip)
automount(pid422) on /misc type autofs (rw,fd=5,pgrp=422,minproto=2,maxproto=3)


If I look at the properities of the KDE desktop Icons related to the cdroms I get:

Icon called CDROM shows a URL of /mnt/cdrom
(This one points to the not working CDROM)

Icon called CDROM2 shows a URL of /mnt/cdrom2
(This one points to the working CDRW)


If I type cdrecord -scanbus at the prompt I get:

Cdrecord 1.8.1 (i686-pc-linux-gnu) Copyright (C) 1995-2000 Jörg Schilling
Using libscg version 'schily-0.1'
scsibus0:
0,0,0 0) 'Memorex ' 'CRW-1622 ' 'D4.0' Removable CD-ROM
0,1,0 1) *
0,2,0 2) *
0,3,0 3) *
0,4,0 4) *
0,5,0 5) *
0,6,0 6) *
0,7,0 7) *

Just tried changing fstab file. I'm going to reboot and then I'll post another message.

The kernel is version 2.215-4mdk

Thanks

Ok, just restarted wit the lines you provied for fstab. Now if I go to the /mnt directroy and do a ls on /mnt/cdrom or mnt/cdrom2 I jut get another prompt. No error but no list either. If I go into KDE and try by clicking on the icons I get a blank folder with no contents and no error.

When I typed mount /dev/cdrom or mount -tiso9660 -o ro /dev/hdc /mnt/cdrom I get the message /dev/hdc is not a valid block device.

Perplexing . . .

What does "Not a valid bolck device mean?"

SUCCESS!!!

I found the problem. The Acer CDROM I was using, seems to not be supported by Linux. Go Figure. I swapped it out for another one, and now it works. Guess I should have tried that first. This still doesn't explain what it worked for a while after the first install. And during the install. Anyway, thank you very much for your help.