Yet another 'missing' CDROM thread...

**TheDevilsJester** · 04-15-2005, 04:03 AM

I just installed knoppix 3.8 (debian style), and while my CD ROM was detected and working perfectly in the live version, the hdd version fails to detect it.

Now I have read the many posts on this topic, but all of the solutions say to link to /dev/sr0 or similar (which isnt a valid device on my system).

When I look at dmesg, I get:

Code:

hdc: SONY DVD RW DRU-710A, ATAPI CD/DVD-ROM drive

and

Code:

ide-cd: passing drive hdc to ide-scsi emulation.

Nothing else in dmesg seems relevent.

I tried symlinking to /dev/hdc, but even that wont work.

This is using only the 2.6 kernel (3.8 doesnt install anything else)

My relevent lilo.conf portion is:

Code:

image=/boot/vmlinuz-2.6.11
	label="Linux(2.6)-1"
	initrd=/boot/initrd.img-2.6.11
	append="ramdisk_size=100000 lang=en apm=power-off hda=scsi hdb=scsi hdc=scsi hdd=scsi hde=scsi hdf=scsi hdg=scsi hdh=scsi nomce "
	read-only

Any assistance on this would be appreciated.

**mr_ed** · 04-15-2005, 05:39 AM

Good for you for doing your homework!

Every new version of something brings new surprises, eh?

Your dmesg shows that the drive is being detected - it's just not where you can find it. To see where Knoppix put the thing do this: $ cat /etc/fstab. Here's part of mine, from my shiny-fresh installation of 3.8.1:

Code:

# /etc/fstab: filesystem table.
#
# filesystem  mountpoint  type  options  dump  pass

/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

Now, where are you having problems? From the KDE desktop? When I hovered my mouse over the CD-ROM icon, I saw that the shortcut pointed to /mnt/cdrom.

Well, that won't work! To change it, I right-clicked on the icon, left-clicked on Properties, left-clicked on the URL tab, and changed it to just /cdrom.

Does that help?

-- Ed

**eco2geek** · 04-15-2005, 08:27 AM

I don't use LILO, so please take anything I say about it with a grain of salt.

Please try it again after nuking all the "hdx=scsi" entries from lilo.conf and rerunning (here's the "take with a grain of salt" part) /sbin/lilo. This kernel doesn't use SCSI emulation for CD drives any more and, in my experience, often won't mount them if the "hdx=scsi" parameter is there.

Knoppix includes an automounter daemon by default, so you can usually easily tell when you've got it set up correctly by firing up Konqueror with a CD in the drive and clicking the "+" by the /mnt directory in the left-hand pane. The automounter should detect that there's a CD in the drive and create a symlink to /mnt/cdrom.

**mr_ed** · 04-15-2005, 09:38 AM

Oh. Yeah. What he said.

You absolutely must run lilo after making any changes to the file /etc/lilo.conf in order for those changes to get written to the boatloader.

Ummm, about those 8 hard drives (hda ... hdh).... LILO notation is hd and then a letter for each physical drive, and then a number for each partition on that drive.

One of my computers has only one hard drive, and it has these partitions: hda1, hda2, hda3, (hda4 is an extended partition), and hda5 ... hda11.

The other computer has two hard drives, so if I had LILO installed instead of GrUB the partitions would be: hda (Windows has the whole drive), hdb1, hdb2, hdb3.

... firing up Konqueror with a CD in the drive and clicking the "+" by the /mnt directory in the left-hand pane

Okay, I give.

There have been times when clicking on the little disk icon on the desktop hasn't worked for me when it was set to /mnt/cdrom, with both Knoppix 3.7 and 3.8.1. And now it does.

So I'll withdraw my suggestion about changing the icon and let you focus on your /etc/lilo.conf.

-- Ed

**TheDevilsJester** · 04-15-2005, 11:57 PM

If I remove all of the hd*=scsi flags from the kernel line, the kernel fails to boot (it wont even get past the "Loading Linux................" portion) I tried this after reading someone else post before I even posted...

However, something I just tried, if I remove just the hdc=scsi portion (and leave the rest), my cdrom works perfectly.

It seems to me that the kernel wants =scsi for my harddrive or it wont boot up...odd

So problem fixed.

**eco2geek** · 04-16-2005, 02:06 AM

It seems to me that the kernel wants =scsi for my harddrive or it wont boot up...odd

That's very interesting. Will have to remember that.

<edit>
If you feel like experimenting, you might try it without the ramdisk (i.e. delete the "initrd=/boot/initrd.img-2.6.11" line, and the "ramdisk_size=100000" parameter), then see if it works without the "hdx=scsi" parameters.

The ramdisk may be why the "hdx=scsi" parameters are still necessary for you.

(Unless you do, in fact, have a SCSI hard disk...)

**CrashedAgain** · 04-18-2005, 01:23 AM

Originally Posted by TheDevilsJester

I just installed knoppix 3.8 (debian style), and while my CD ROM was detected and working perfectly in the live version, the hdd version fails to detect it.

Now I have read the many posts on this topic, but all of the solutions say to link to /dev/sr0 or similar (which isnt a valid device on my system).

Actually it's /dev/scd0 you must link to. For a permanent fix with a Knoppix install I had to modify /etc/init.d/knoppix-autoconfig. See this post: http://www.knoppix.net/forum/viewtopic.php?t=13601

I would have thought *they* would have fixed this by now, this bug first appeared in 3.4 with the introduction of the 2.6 kernel. This is one of the reasons I have switched to Kanotix; it has fewer bugs like this and those that do appear get fixed.