/dev/cdrom invalid block device.
 

Last night I tried several times to install Debian (Woody) on a couple of spare partitions.
All went well until just after the reboot. When it came to the time to install packages from the cd it wouldn't find the cd. I kept getting the message "/dev/cdrom is not a valid block device. I tried again with the 2.2 kernel and with the 2.4 kernel with the same result.
Has anyone any ideas?

Thanks in advance legin

I had this, still don't know why, but when I'd type /dev/cdrom, I got nothing. /dev/cdrom0, however, worked just fine... :(

Hope it helps.

if the cdrom is loaded with ide-scsi, it would be /dev/scd0 instead of
/dev/cdrom.

if you run cdrecord --scanbus
at the terminal and your cdrom drive shows up there, that's what it is.

should'nt /dev/cdrom be a symlink to a block device??
mine goes to /dev/hdc

for instance if /dev/cdrom was symlinked to /dev/hdc, a cdrom or cdrw
drive, and was setup that way, then ide-scsi was used during boot,
so the drive could be used as a cdwriter, /dev/hdc and thus /dev/cdrom
would no longer be a valid block device.

that's my guess anyway.

I have to reopen this thread, since I'm having the same trouble on my unstable (knoppix 3.2 installed to HD) system. I've tried kernel 2.4.22, 2.4.24 & 2.6 (as well as the suggestions in this thread), to no avail. Here's the relevant output from dmesg, it looks like /dev/sd0 should be valid, right?

=========================================
hdd: CD-224E, ATAPI CD/DVD-ROM drive
ide-cd: passing drive hdd to ide-scsi emulation.
hdd: attached ide-scsi driver.
SCSI subsystem driver Revision: 1.00
scsi0 : SCSI host adapter emulation for IDE ATAPI devices
Vendor: TEAC Model: CD-224E Rev: K.0B
Type: CD-ROM ANSI SCSI revision: 02
=========================================

Any & all suggestions would be appreciated!!

OK, I booted my trusty, crusty old kernel via floppy & the cdrom attached fine. Here's dmesg from that boot:

========================================
Mar 12 12:54:06 gwlap kernel: SCSI subsystem driver Revision: 1.00
Mar 12 12:54:06 gwlap kernel: scsi0 : SCSI host adapter emulation for IDE ATAPI devices
Mar 12 12:54:06 gwlap kernel: Vendor: TEAC Model: CD-224E Rev: K.0B
Mar 12 12:54:06 gwlap kernel: Type: CD-ROM ANSI SCSI revision: 02
Mar 12 12:54:06 gwlap kernel: Attached scsi CD-ROM sr0 at scsi0, channel 0, id 0, lun 0
Mar 12 12:54:06 gwlap kernel: sr0: scsi3-mmc drive: 24x/24x xa/form2 cdda tray
Mar 12 12:54:06 gwlap kernel: Uniform CD-ROM driver Revision: 3.12
========================================

Looks like what's missing in the first instance is the last three lines. sr0 is symlinked to sda1 in /dev.

??????

sda1 is a scsi hard drive

on my machine /dev/scd0 is the first scsi emulated hard drive.

see if any drives show up under
cdrecord --scanbus
as root

the 2 modules that need to be loaded are ide-scsi and sg

if cdrecord sees the drives, the modules are loaded.

I'll apt-get cdrecord, but I know ide-scsi is loading, from reading dmesg, so I guess sg is not. Is there a way to make sg load, or to build/install it??

Run modconf as root to get those modules to load.

OK, I apt-getted cdrecord & here's the output of --scanbus:

========================================================
Linux sg driver version: 3.1.25
Using libscg version 'schily-0.8'.
scsibus0:
0,0,0 0) 'TEAC ' 'CD-224E ' 'K.0B' Removable CD-ROM
========================================================

So both of the necessary modules are loaded. What is this telling me that my cdrom drive is? in /dev, cdrom is a symlink to /dev/scd0. sr0 is a symlink to scd0 (not /dev/scd0).

Thanks for all the prompt responses.

what are you trying to do that's not working.
i thought you were trying to burn a cd.

having the symlink correct is for cd players and rippers mostly.

having the ide-scsi and sg are for cdrecord.

if you have your boot loader ignore the cdrom drive, so you can set it
up as ide-scsi for cdrecord, and it doesn't get set up right, you can't
do anything with the drive.

it looks like you are set up properly for both.

I'm just trying to get my cd player to show up properly. It's not a burner, but cdreord was useful to know if the system would see it.

I'm stumped ... it is set up in fstab, on boot it's getting passed to the ide-scsi driver, sg is being utilized, but I keep getting the "not a valid block device" error. I've compiled my kernel with SCSI & SCSI generic support, I've tried using /dev/sda1, /dev/scd0, /dev/sr0. The only way I can get it to show up is to boot my original kernel, Knoppix installed to the hard disc.

you can try mounting a data disk as various devices to see what is up with the disk.

mkdir /mnt/cdrom
mount /dev/scd0 /mnt/cdrom
mount /dev/hdc /mnt/cdrom
mount /dev/hdd /mnt/cdrom

* Tried those, still no joy.

root@gwlap:/# mount -t iso9660 /dev/hdd /cdrom
mount: wrong fs type, bad option, bad superblock on /dev/hdd,
or too many mounted file systems
(could this be the IDE device where you in fact use
ide-scsi so that sr0 or sda or so is needed?)

root@gwlap:/# mount -t iso9660 /dev/sr0 /cdrom
mount: /dev/sr0 is not a valid block device

root@gwlap:/# mount -t iso9660 /dev/sda /cdrom
mount: /dev/sda is not a valid block device

root@gwlap:/# mount -t iso9660 /dev/so /cdrom
mount: special device /dev/so does not exist

* I recompiled my 2.4.22 kernel without SCSI emulation, now HDD is being picked up by ide-cdrom.

Mar 14 10:17:23 gwlap kernel: Kernel command line: BOOT_IMAGE=2.4.22 ro root=306 hda=scsi hdb=scsi hdc=scsi hde=scsi apm=power-off nomce
Mar 14 10:17:23 gwlap kernel: ide_setup: hda=scsi
Mar 14 10:17:23 gwlap kernel: ide_setup: hdb=scsi
Mar 14 10:17:23 gwlap kernel: ide_setup: hdc=scsi
Mar 14 10:17:23 gwlap kernel: ide_setup: hde=scsi
Mar 14 10:17:23 gwlap kernel: hdd: attached ide-cdrom driver.
Mar 14 10:17:23 gwlap kernel: hdd: ATAPI 24X CD-ROM drive, 128kB Cache, DMA
Mar 14 10:17:23 gwlap kernel: Uniform CD-ROM driver Revision: 3.12

* But I don't know how or where to mount it!!

mount -t iso9660 /dev/hdd /cdrom
hdd:communication error: status=0x51 <<<<<<PANIC!!>>>>>>>

This may have been an audio CD, but I assume I need to change fstab to /dev/hdd /cdrom, correct??