Recipe 11.3. Enabling SCSI Emulation for IDE/Atapi CD and DVD Writers
11.3.1 Problem
Your CD-writing program
(whether it's cdrecord or one
of the good graphical programs such as X-CD-Roast or K3b) reports
that it cannot find any drives on your system, or it sees your
CD-R/RW drive just fine but does not see your CD-ROM drive, so you
can't copy discs.
11.3.2 Solution
Make sure the IDE-SCSI emulation system is enabled and your drives
are configured to use it. This applies only to the
2.4 Linux kernel, because the 2.6
kernel supports IDE/ATAPI drives directly, using the standard
/dev/hd* designations.
First, verify that the ide-scsi pseudo-device
driver is available:
$ locate ide-scsi.o
/lib/modules/2.4.21/kernel/drivers/scsi/ide-scsi.o
Next, there are two text files to edit:
/etc/modules.conf,
and the configuration file for your bootloader. (Debian users, please
refer to the "Discussion" section
of this recipe, as file locations are different.) First, find the
device names for your drives:
$ dmesg | grep '^hd.:'
hda: IBM-DTLA-305020, ATA DISK drive
hdb: TOSHIBA DVD-ROM SD-M1202, ATAPI CD/DVD-ROM drive
hdc: LITE-ON LTR-24102B, ATAPI CD/DVD-ROM drive
The CD drives are hdb and
hdc. Add the following to
/etc/modules.conf:
alias scsi_hostadapter ide-scsi
options ide-cd ignore="hdb hdc"
alias scd0 sr_mod
pre-install sg modprobe ide-scsi
pre-install sr_mod modprobe ide-scsi
pre-install ide-scsi modprobe ide-cd
Next, LILO users, add the following to the end of
lilo.conf, using the hd*
designations for your devices:
append="hdb=ide-scsi"
append="hdc=ide-scsi"
GRUB users, add the following to /etc/grub.conf
at the end of the kernel line, using the hd*
designations for your devices:
hdb=scsi hdc=scsi
It should look like this, all on one line:
kernel /boot/vmlinuz-2.4.21 root=/dev/hda1 ro hdb=scsi hdc=scsi
Reboot, then verify that the ide-scsi module
loaded:
$ lsmod | grep ide-scsi
ide-scsi 9456 1
scsi_mod 55124 2 [ide-scsi sr_mod]
Now when you run cdrecord -scanbus it should
show SCSI device names for all the drives you configured to use
IDE-SCSI, and you should be ready to start CD writing.
Note that the device names are changed now, so when you mount the
discs the device names won't be
/dev/hd* any more, but rather
/dev/scd*. You'll probably want
to update /etc/fstab with the new
/dev names.
11.3.3 Discussion
Debian's module configuration files are in different
locations. First, Debian uses /etc/modules and
/etc/modutils/idecd_opts. Add:
ide-scsi
to /etc/modules. Then add:
options ide-cd ignore="hdb hdc
to /etc/modutils/idecd_opts.
There is no downside to running all of your CD/DVD drives under the
IDE-SCSI subsystem, except for having different device names.
The 2.6 kernel needs no special steps. Simply use the
/dev name:
$ cdrecord dev=/dev/hdc <commands>
Remember, you can use a cdrecord group to grant
permissions to users for cdrecord.
11.3.4 See Also
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