CDRW drives (was Re: [Techtalk] wireless woes)

[Conor Daly]

On Tue, Jan 21, 2003 at 02:14:11AM -0500 or so it is rumoured hereabouts, 
Andrew thought:
> On Monday 20 January 2003 10:37 pm, you wrote:
> > Oh wait, there's more! It appears as though although my cd-rom works, the
> > burning part doesn't. I'm not sure how my kernel was compiled but I feel
> > like a whole lot of options didn't make the cut somehow. (Friend of a
> > friend compiled the kernel for me and managed to NOT get: printing, usb or
> > my cdburner working.)
> >
> > debian:/usr/src/linux# cdrecord -scanbus
> > Cdrecord 1.10 (i686-pc-linux-gnu) Copyright (C) 1995-2001 Jörg Schilling
> > cdrecord: No such file or directory. Cannot open SCSI driver.
> > cdrecord: For possible targets try 'cdrecord -scanbus'. Make sure you are
> > root
> >
> > Just makes me want to cry.
> Emma Jane Hogbin,
> 
> 	Take heart, the cdrom problem is likely a common one. I just went through it!
> Unfortunately I risk making fellow listers upset, at least those 
> who helped me a lot, but I don't feel yet able to trouble shoot your 
> situation. 

Andrew,

It takes a while to get to the stage where you feel comfortable
troubleshooting someone else's problem but don't worry, you'll get there.
It's often helpful, both to the questioner and to the wannabe helper, to
detail "this is what _I_ did to make it work".  The helper gets to review
what (s)he did and can do it again with a new machine later while the
questioner gets to say "Ah!  I missed _that_ step!".

As to the question of annoying fellow listers, you won't annoy folks just
by asking lots of questions _so long_ as they can see that _you_ have
already made an effort to answer the question yourself first.  It's
worthwhile reading Eric S Raymond's "How to ask good questions" (or
something like that).  It's available somewhere under
http://tuxedo.org/~esr/writings(.html?) 

Just rereading your words above, it looks to me like you're worrying that
people will be annoyed that you didn't regurgitate the help _you_ received
for the same problem.  Again, the newbie not feeling comfortable thing
means that you may not be happy to post _advice_ yet.  What you _can_ do,
is to look up the archives, find the thread that helped _you_ and post a
"I had the same problem, I got a lot of help here, here's a URL for the
thread in the archives" response.  Remember to include the URL to the
archive though!  That allows you to help without worrying that you might
be giving out bad advice...



Emma Jane,

I posted a brief "getting my IDE CDRW drive to work" on techtalk last
September.  It's in the archive at:

http://mailman.linuxchix.org/pipermail/techtalk/2002-September/015877.html

Essentially there are three steps:

1.  Tell the kernel that /dev/hdx is to be handled with the ide-scsi
    emulator.  Add 

	append="hdx=ide-scsi"

    to your lilo.conf and do 'lilo' to install.  Or add

	hdx=ide-scsi

    to the "kernel=" line in your grub.conf.

2.  Make cdrecord available to users (so you don't have to be root).

	chmod +x /usr/bin/cdrecord

3.  Tell cdrecord where to find the CDRW drive.

	cdrecord -scanbus

    Put the numbers returned by this into /etc/cdrecord.conf along with
    stuff like the max writing speed for the drive (cdrecord.conf is well
    commented so you should have no trouble with that bit)

Thassit!

Note:  /dev/hdx should be replaced with the actual device for your drive.
       eg. /dev/hdc for the secondary master IDE device

The error you received from cdrecord -scanbus means one of two things:

1.  You didn't run it as root and it's not suid (step 2 above) so you
    don't have permission to access the ide-scsi device.  Run as root and
    see if you get a result.

2.  The ide-scsi module isn't loaded.  As root do

	lsmod

    and see if ide-scsi is in the list.  If it isn't, do

	modprobe ide-scsi

    and try lsmod and cdrecord -scanbus again (If you compiled ide-scsi
    directly into the kernel, lsmod and modprobe won't help).

If neither of the above work, you can test if the hdx=ide-scsi kernel
parameter worked by doing the following:

Insert a CD containing data into the CDRW drive.  As root, do

	mount -t iso9660 /dev/hdx /mnt/cdrw

(assuming /mnt/cdrw exists and substituting the real CD device for
/dev/hdx).  

[root at Valkerie root]# mount -t iso9660 /dev/scd0 /mnt/cdrom/
mount: block device /dev/scd0 is write-protected, mounting read-only
#### This is the ide-scsi emulation ####

[root at Valkerie root]# mount -t iso9660 /dev/hdc /mnt/cdrom/
mount: /dev/hdc is not a valid block device
#### I think there's no drive here ####

[root at Valkerie root]# mount -t iso9660 /dev/hdd /mnt/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?)
#### This is my CDROM but ide-scsi has the device instead ####

If the mount command works for /dev/hdx then the kernel ide-scsi parameter
didn't take effect.  Did you run 'lilo' after you edited /etc/lilo.conf?
 

On my system:

in /etc/lilo.conf

image=/boot/vmlinuz
	label=Rh70-scsi
	read-only
	root=/dev/hda4
	append="hdd=ide-scsi mem=128m"

in /etc/grub.conf

kernel /boot/vmlinuz ro root=/dev/hda1 mem=127M vga=0xf07 hdc=ide-scsi hdd=ide-scsi

[root at Valkerie root]# lsmod
Module                  Size  Used by
ide-scsi                7776   0 

in /etc/cdrecord.conf

CDR_DEVICE=phillips
#CDR_DEVICE=LG

# 
# The default speed, if not specified elswhere
#
CDR_SPEED=2

# drive name	device	speed	fifosize driveropts
#
phillips=	0,0,0	12	4m	""


[root at Valkerie root]# cdrecord -scanbus
Cdrecord 1.10 (i686-pc-linux-gnu) Copyright (C) 1995-2001 Jörg Schilling
Linux sg driver version: 3.1.19
Using libscg version 'schily-0.5'
scsibus0:
cdrecord: Warning: controller returns wrong size for CD capabilities page.
	0,0,0	  0) '  ATAPI ' '52X CDROM       ' '1.40' Removable CD-ROM
        ^^^^^
device scsi id.

Actually, the CDRW drive isn't in this machine just now so you only see
the CDROM drive but the principle is the same.


Conor
-- 
Conor Daly <conor.daly at oceanfree.net>

Domestic Sysadmin :-)
---------------------
Faenor.cod.ie
  9:09pm  up 78 days,  5:53,  2 users,  load average: 0.08, 0.02, 0.01
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