CD drive unavailable ...

[asearle]

I installed Knoppix 4.0 for a friend and it looks like the CD was badly connected at the time of install (wrong jumpers set). Somehow (however) the install ran through fine and everything (apart from the CD is working fine).

Now I am trying to clear the problem but find that I cannot get the system to talk to the CD:

I can see the CD declared at boot (Knoppix script) and I can see the cd (/dev/hdc) when I open qtparted but the CD doesn't appear in BIOS settings and also is not available from KDE:

When I click on the standard CD icon I get the message:

"Commnd not available: The file or directory file:///mnt/cdrom does not exist"

But when I look in /mnt/cdrom I see a shortcut with the properties saying it points to: /mnt/auto/cdrom ... which seems normal.

I then tried to create a new icon and found that a device /dev/cdrom (/cdrom) was available for selection. However, after creating the icon then, when I tried to open the device I got the following:

"Drive couldn't be attached. The error was: mount: /dev/cdrom is not a valid block- orietated device"

Does anyone have an idea for me here? Indeed, I believe that during installation, I confused the system and now, even though the CD is now available, it is having trouble linking it in.

But I believe that there must be a script that I can change to get the system to talk to the CD.

Any tips would be a great help for me as I am not sure whether I should correct this in the BIOS or in Knoppix/Debian. Or whether I should check to see if any connections/settings are (still) wrong (but I don't think so).

I just hope that I don't have to re-install.

Many thanks for any tips that you can give me.

Regards,
Alan Searle

[nad]

"it looks like the CD was badly connected at the time of install (wrong jumpers set)"

"the CD doesn't appear in BIOS settings"

First of all I would make certain that the jumpers and cabling are correct and that the device has _no_ recognition issues before going any further.

This alone may clear everything up. If not, have you looked in your startup log ( "I can see the CD declared at boot" ) to see what is going on at boot? The command: dmesg will show your current boot log from the file /var/log/messages. You may pipe the output through less, more, head or tail for convenience; man less, man more, man head, man tail; or view the file with any text editor.

If you continue to have problems, please post back with more information.

[asearle]

Hi Nad,

Thanks for your information and, yes, I have been trying out a few things: I tested with a CD that I took from another PC and found that ...

1. The BIOS didn't find the CD: The hard disk was recognised as Primary Master but the CD was not displayed (as secondary master?). I tried running autodetect (in BIOS) but the PC still only found the HDD.
2. I then went on to boot Knoppix and, in the early lines of the boot process, I saw:
activating DMA accelleration for: hda [myhdd]
activating DMA accelleration for: hdc [mycddrive]
3. After booting, Knoppix had added an icon to the desktop for the new CD drive
4. The CD drive was visible (and active) as hdc when viewed with QTPartEd
5. But when I inserted a data CD and right-clicked on 'open', I got the message "The command cannot be carried out. The file or the directory file:///mnt/cdrom does not exist".
6. So I went to take a look in /mnt and found that, yes, there was a file (a link) to 'cdrom'.

So I am quite confused now:

It looks like there is a problem with the BIOS (the cdrom doesn't appear) but knoppix recognises a cd drive and seems to install it OK. But then it refuses to read that drive.

I would like to diagnose this problem but am not sure whether I should concentrate on the BIOS or on Knoppix.

I'll do some more testing and then give more feedback to the forum: I'm hoping it's just a simple thing.

Many thanks for your help.

Regards,
Alan Searle.

[asearle]

I have been comparing the way other installations handle CDROM drives this and notice that ...

A. In /mnt there is a link called 'cdrom' which points to the directory /mnt/auto/cdrom
B. On my problem PC the link exists (and, if deleted, is recreated on boot) but the directory does not.

If anyone can help me further with this problem of the CD drive which is visible and detected but not readable, then that would be a great help.

Regards,
Alan Searle.

[asearle]

This is such a strange thing: When I put a new (data) cd in, I can hear the PC reading the contents. I then go to the CD symbol and try to open it and get the error message: ... the file or directory file:///mnt/cdrom does not exist.

I even tried manually creating the directory /mnt/auto/cdrom (which /mnt/cdrom points to) but the system didn't allow this (even though I was root).

I then tried to create a manual icon/link and found that, under device I could see /dev/cdrom (which had apparently been recognised) but once I had created the icon, I found that, when I tried to open it, I got "Drive could not be mounted. mount: /dev/cdrom is not a valid device".

This is so strange because Knoppix seems to have detected the drive and seems to be talking to it, but I cannot access it from the desktop or in the file system.

I'll trawl through my Knoppix manual again.

Regards,
Alan Searle

[OErjan]

to me, this sounds like jumpering or cable that is not corectly done (or wrong type). check again.
normally the cable should be like this

|
|motherboard----------slave----master
|

and the jumpers should match.
check and doublecheck, I try to avoid cable-select when jumpering, it is a frequent source of errors for me.

[nad]

Linux device drivers, out of necessity, read the wires. Try a dell system some time, I have found unused circuitry on many boards.

That being said, it is quite likey that knoppix sees the cd drive, yet, because the bios is not assigning resources for it, it is unavailable.

Please see the comment in my first post, "First of all I would make certain that the jumpers and cabling are correct and that the device has _no_ recognition issues before going any further".