CD R/RW: reads or writes but not both
 

Hi, I'm newbie-ish, so please have pathience...

I recently replaced a broken CD-ROM with a CD R/RW. I'm using Mandrake 7.2 (old version), and when I booted, kudzu detected the new hardware and presumably configured it.

At first it functioned OK as a CD-ROM, but if I tried cdrecord -scanbus (as root) I got an error that it couldn't find an SCSI driver. Also, I was getting odd error messages about the CD R/RW when booting. I at least figured out that this was because I needed to load the ide-scsi module.

So I added hdc=ide-scsi to the end of the linux command line in /boot/grub/menu.lst and also put append="hdc=ide-scsi" in /etc/lilo.conf even though I don't use it. This caused boot-time messages to go away but cdrecord -scanbus still failed.

Then I added the line "ide-scsi" to /etc/modules and when I rebooted, kudzu came up again and reconfigured my CD R/RW, and cdrecord -scanbus appeared to work! I thought I had fixed everything but in actuallity, I can't even read from my CD anymore! Saying "ls /mnt/cdrom" gives me: "Input/Output error". Just clicking on the CD-ROM icon gives me a message box "You do not have access rights to this location".

Here's the output of cdrecord -scanbus
Cdrecord 1.9 (i586-mandrake-linux-gnu) Copyright (C) 1995-2000 Jörg Schilling
Linux sg driver version: 2.1.39
Using libscg version 'schily-0.1'
scsibus0:
0,0,0 0) 'CDWRITER' 'IDE5232 ' 'A030' Removable CD-ROM
0,1,0 1) *
...
0,7,0 7) *

Here are *two* entries in /etc/sysconfig/hwconf (kudzu's database):
-
class: CDROM
bus: IDE
detached: 0
device: hdc
driver: ignore
desc: "CD-RW IDE5232"
-
class: CDROM
bus: SCSI
detached: 0
device: scd0
driver: ignore
desc: "Cdwriter IDE5232"
host: 0
id: 0
channel: 0
lun: 0
-

Please help -- my head is starting to hurt badly :(

make sure /dev/hdc is read/write for all users. run:
(i think).

then look in fstab and make sure that the mount options are correct for /dev/hdc.
post your fstab if you have any questions about it.

Thanks for replying.

$ ls -l /dev/hdc
brw------- 1 daniel cdrom 22, 0 Sep 27 2000 /dev/hdc

Which should be good enough for me (daniel) but I tried

$ chmod a+rw /dev/hdc
$ ls -l /dev/hdc
brw-rw-rw- 1 daniel cdrom 22, 0 Sep 27 2000 /dev/hdc

anyways, and it still doesn't work. I get the same errors. Here is the relevant lines of /etc/fstab:
[edit]
/dev/cdrom is indeed a link to /dev/hdc, BTW
[/edit]

with ide-scsi module hdc changes device name.
look at output of:

and
to determine your device's new name.
likely it will be /dev/sr0 or /dev/scd0

Thanks for the reply.

I don't seem to have either of the programs/files sg_scan or sg_map. However, running on pure desperation, I removed /dev/cdrom and then linked it to /dev/scd0 like this:
stuck a CD in the tray and ls /mnt/cdrom worked! So, I guess thanks very much for the idea! :)

Now, is this really the right way to go about things? I haven't tried burning anything yet. If anyone can give me a reason why this is or isn't the correct way to fix the problem, I would still appreciate a few more replies.

Thanks a million, though!

I'm not familiar with Mandrake or Suse or auto/supermount.
Just wanted to say that first :D

If you're using a 2.4.xx kernel, AND loading the ide-scsi module AND passing the /dev/hdc=ide-scsi parameter at boot, then yes, mapping /dev/hdc to /dev/sr0(or scd0) is the right way.

Your distro may have a different way of doing things.

Well, just FYI, Mandrake 7.2 has a 2.2 kernel. I'm planning to upgrade but would kinda like to backup my home directory first which is why I am bothering with getting my CD burner to work. :)

Thanks again for the help!