CDROM not recognised/opening after install

[mr_ed]

Before running the MAKEDEV script to try fixing the mess made by Knoppix-installer, let's see whether Linux knows that you have a CD drive and where it really put it (as opposed to all the misleading clues about its location from Knoppix-installer).

Information about hardware detection is in the text that flies by during boot-up. It should still be there on your system.

If you have a scrolling terminal, type

$ dmesg

If your terminal doesn't scroll, type

$ dmesg|less

Look for a description of your drive, probably near the bottom of everything. You should see Vendor, Model, Rev., Type.... If you can't find this at all, then Linux doesn't even know the drive exists. But since this is Knoppix, it most probably was found.

There might be a line like this (reading from my dmesg)

> sr0: scsi3-mmc drive: 40x/40x writer cd/rw et cetera

Then maybe a line like this:

> Attached scsi CD-ROM sr0 at scsi0, channel 0, id 0, lun 0

If so, congratulations! Your drive is at /dev/sr0.

Then when I type

$ ln -l /dev/sr*

I see that /dev/sr0 is symlinked -> scd0

Then I type

$ ln -l /dev/scd*

and see that yes, /dev/scd0 really exists. So I can call it /dev/sr0 or I can call it /dev/scd0, but now this command (sudo or su to root) really and truly makes my CD drive work:

# mount -t iso9660 /dev/sr0 /cdrom

If you find that your CD drive was autodetected, and that the mount command works, then edit that line in your /etc/fstab file.

Change
> /dev/cdrom

to
> /dev/whatever

This will take effect the next time you boot.

-- Ed

[raj1478]

If your CDROM is working well in windows, then just follow the steps:
1. cd /dev
2. ls -l /dev/scd*
3. If there are scd0 or scd1 etc. listed and your CDROM is Secondary Master then
2. ln -s /dev/scd0 cdrom

Then try to mount to the CDROM...

[mr_ed]

Tangential advice: if you know how to fish, teach others. Then they can feed themselves - and teach even more people - rather than coming back again and again for more fish.

-- Ed

[raj1478]

Final advice: if you know how to fish, teach others. That way they can feed themselves - and teach even more people - rather than coming back again and again for more fish.

-- Ed

I couldn't understnd the meaning of this post...

Please clarify...

[Victor Warner]

raj1478 and Ed

Thanks again. I tried what you both suggested.

Using dmesg, I did the same message as Ed (Attached scsi CD-ROM sr0 at scsi0, channel 0, id 0, lun 0)

I typed "mount -t iso9660 /dev /sr0 /cdrom"

But I got this message in return:

mount: block device /dev/sr0 is write-protected, mounting read-only
mount: wrong fs type, bad option, bad superblock on /dev/sr0,
or too many mounted file systems

From this I am not sure what if anything I need to change in the fstab file.

I would be grateful to know what the next step is...

Victor Warner

[raj1478]

Thanks again. I tried what you both suggested.

Victor Warner[/quote]
Hi, I've seen in my knoppix harddisk-install that /dev/cdrom is a symbolic link to /dev/scd0, that is why I'd suggested you to give the command "ln -s /dev/scd0 cdrom" in the "/dev" directory. Had you tried it?

If yes then simply type "mount /cdrom" at the prompt or click on the CDROM icon you created.

Post the results...

[mr_ed]

Victor, knoppix-installer sprayed so many different references to the CD drive around, and we've been hacking against it so long, that two possibilities come to mind:

- the latest attempt conflicts with something k-i put in place;

- something you did earlier in the session already tied up the drive.

These could have happened either on the /dev side of things or with the mount point (/cdrom, /mnt/cdrom, etc.).

Also, k-i did something just enough different in my case that what worked for me might not work for you. (It gave me two entries for CD-ROM drives in /etc/fstab as well as a third for a DVD drive - all for one physical unit - and the CD drives were mounted to nonexistant points in /mnt/auto.)

If adding another link doesn't work, you could try:

- unmounting (umount) the drive before trying to mount it again - you can specify the /dev view of it or the mount-point view;

- rebooting to clear out any temporary silliness that may have happened;

- manually going through and deleting the extra, useless directory entries - first on the mount side of things (/mnt/cdrom etc.) and then, if desperate, in /dev.

-- Ed

[Victor Warner]

I am still no further forward

Raj1478:

I did type in "ln -s /dev/scd0 cdrom": I got this reply:
[quoteln: `cdrom': File exists
[/quote]

I then typed in "mount/cdrom" and then got this reply:

mount: wrong fs type, bad option, bad superblock on /dev/cdrom,
or too many mounted file systems

Ed: I tried what you suggested (as far as I understood it) but still no go.

What I am not clear exactly what (and exactly where) I should be deleting things.

Victor Warner

[raj1478]

Check your boot parameters and post them. The parameters can be found in "/etc/lilo.conf" or "/boot/grub/grub.conf" depending upon whether you are using "lilo" or "grub" as boot loader.

Is this CDROM doing well in Windows? There is an entry of DVD drive in your "fstab" file. Do you have DVD drive or combo drive? If yes, where is it connected?

[Victor Warner]

raj1478

1. It is a CDROM and not a DVDROM
2. The CDROM does perform well in Windows (Win2k)
3. Since there is a no DVDROM should I be deleting the reference to the DVD drive in the fstab file


Below is the lilo.conf file and the fstab file

Victor Warner

LILO.CONF

# /etc/lilo.conf - See: 'lilo(' and 'lilo.conf(5)',
# --------------- 'install-mbr(', '/usr/share/doc/lilo/',
# and '/usr/share/doc/mbr/'.

# +---------------------------------------------------------------+
# | !! Reminder !! |
# | |
# | Don't forget to run 'lilo' after you make changes to this |
# | conffile, '/boot/bootmess.txt', or install a new kernel. The |
# | computer will most likely fail to boot if a kernel-image |
# | post-install script or you don't remember to run 'lilo'. |
# | |
# +---------------------------------------------------------------+

# Support LBA for large hard disks.
#
lba32

# Overrides the default mapping between harddisk names and the BIOS'
# harddisk order. Use with caution.
#disk=/dev/hde
# bios=0x81

#disk=/dev/sda
# bios=0x80

# Specifies the boot device. This is where Lilo installs its boot
# block. It can be either a partition, or the raw device, in which
# case it installs in the MBR, and will overwrite the current MBR.
#
boot=/dev/hda

# Specifies the device that should be mounted as root. ('/')
#
root=/dev/hda1

# Enable map compaction:
# Tries to merge read requests for adjacent sectors into a single
# read request. This drastically reduces load time and keeps the
# map smaller. Using 'compact' is especially recommended when
# booting from a floppy disk. It is disabled here by default
# because it doesn't always work.
#
# compact

# Default menu for Debian. (Using the images from debian-bootscreen)
# from Philipp Wolfer <phil@newswriter.org>.
bitmap=/usr/share/lilo/contrib/debian.bmp
bmp-colors=1,,0,2,,0
bmp-table=120p,173p,1,15,17
bmp-timer=254p,432p,1,0,0

# Install the specified file as the new boot sector.
# LILO supports built in boot sectory, you only need
# to specify the type, choose one from 'text', 'menu' or 'bitmap'.
# new: install=bmp old: install=/boot/boot-bmp.b
# new: install=text old: install=/boot/boot-text.b
# new: install=menu old: install=/boot/boot-menu.b or boot.b
# default: 'menu' is default, unless you have a bitmap= line
# Note: install=bmp must be used to see the bitmap menu.
# install=menu
# install=bmp
install=bmp

# Specifies the number of _tenths_ of a second LILO should
# wait before booting the first image. LILO
# doesn't wait if DELAY is omitted or if DELAY is set to zero.

delay=20

# Prompt to use certaing image. If prompt is specified without timeout,
# boot will not take place unless you hit RETURN
prompt
timeout=50

# Specifies the location of the map file. If MAP is
# omitted, a file /boot/map is used.
map=/boot/map

# Specifies the VGA text mode that should be selected when
# booting. The following values are recognized (case is ignored):
# NORMAL select normal 80x25 text mode.
# EXTENDED select 80x50 text mode. The word EXTENDED can be
# abbreviated to EXT.
# ASK stop and ask for user input (at boot time).
# <number> use the corresponding text mode. A list of available modes
# can be obtained by booting with vga=ask and pressing [Enter].
vga=791

# You can set a password here, and uncomment the 'restricted' lines
# in the image definitions below to make it so that a password must
# be typed to boot anything but a default configuration. If a
# command line is given, other than one specified by an 'append'
# statement in 'lilo.conf', the password will be required, but a
# standard default boot will not require one.
#
# This will, for instance, prevent anyone with access to the
# console from booting with something like 'Linux init=/bin/sh',
# and thus becoming 'root' without proper authorization.
#
# Note that if you really need this type of security, you will
# likely also want to use 'install-mbr' to reconfigure the MBR
# program, as well as set up your BIOS to disallow booting from
# removable disk or CD-ROM, then put a password on getting into the
# BIOS configuration as well. Please RTFM 'install-mbr('.
#
# password=tatercounter2000

# You can put a customized boot message up if you like. If you use
# 'prompt', and this computer may need to reboot unattended, you
# must specify a 'timeout', or it will sit there forever waiting
# for a keypress. 'single-key' goes with the 'alias' lines in the
# 'image' configurations below. eg: You can press '1' to boot
# 'Linux', '2' to boot 'LinuxOLD', if you uncomment the 'alias'.
#
# message=/boot/bootmess.txt
# prompt
# single-key
# delay=100
# timeout=100

# Kernel command line options that apply to all installed images go
# here. See: The 'boot-prompt-HOWO' and 'kernel-parameters.txt' in
# the Linux kernel 'Documentation' directory.
#
# append=""
# Boot up Linux by default.
#
default="Linux"

image=/boot/vmlinuz
label="Linux"
initrd=/boot/initrd.img
append="ramdisk_size=100000 init=/etc/init lang=us apm=power-off nomce quiet"
read-only
image=/boot/vmlinuz-2.4.26
label="Linux(2.4)-1"
initrd=/boot/initrd.img-2.4.26
append="ramdisk_size=100000 init=/etc/init lang=us apm=power-off nomce quiet"
read-only

image=/boot/vmlinuz-2.6.5
label="Linux(2.6)-2"
initrd=/boot/initrd.img-2.6.5
append="ramdisk_size=100000 init=/etc/init lang=us apm=power-off nomce quiet"
read-only

# If you have another OS on this machine to boot, you can uncomment the
# following lines, changing the device name on the 'other' line to
# where your other OS' partition is.
#
# other=/dev/hda4
# label=HURD
# restricted
# alias=3
other=/dev/hda3
label="Windows(hda3)"

FSTAB

# /etc/fstab: filesystem table.
#
# filesystem mountpoint type options dump pass
/dev/hda1 / 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/dvd /dvd iso9660 defaults,ro,user,noexec,noauto 0 0
/dev/cdaudio /cdaudio iso9660 defaults,ro,user,noexec,noauto 0 0
# Added by KNOPPIX
/dev/sda1 /mnt/sda1 vfat noauto,users,exec,umask=000 0 0
# Added by KNOPPIX
/dev/hda2 none swap defaults 0 0
# Added by KNOPPIX
/dev/hda3 /mnt/hda3 vfat noauto,users,exec,umask=000 0 0