View Source: SCSI-IDENotes - Waikato Linux Users Group

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scsi-ide is an kernel driver that provides a [SCSI] interface to [IDE] HardDisk / CD / DVD Drives.
It is most commonly used for CD Burning as all burning apparently needs to be done over a SCSI interface.


!! [Kernel] support


To enable this in your kernel you must select the following options:
 ATA/IDE/MFM/RLL support
   IDE, ATA and ATAPI Block devices
     SCSI emulation support

You also need to enable generic SCSI support in your kernel.


You need the following [Kernel] modules, listed with their corresponding options:

; SCSI generic support : __sg.o__, CONFIG_CHR_DEV_SG
; %%% SCSI CD-ROM support : __sr.o__, CONFIG_BLK_DEV_SR
; %%% SCSI support : __scsi_mod.o__, CONFIG_SCSI
; %%% SCSI emulation support : __ide-scsi.o__, CONFIG_BLK_DEV_IDESCSI


!! Boot parameters


Then you will need to add a line similar to the following to your lilo/grub configuration (Example is for lilo)
  append="ignore=hdc,hde hdc=ide-scsi hde=ide-scsi"

This tells the kernel not to use the native IDE driver for hdc and hde and instead to use the ide-scsi driver.
This should give you
/dev/scd0  which would be /dev/hdc otherwise
/dev/scd1  which would be /dev/hde otherwise

Say your CDR is be __hdc__ and the [CDROM] is __hdd__, then you need to add this line to your __/etc/lilo.conf__ to boot with the necessary [Kernel] options:

 append="hdc=ide-scsi hdd=cdrom"



!! Module loading

Now you need to load the __ide-scsi__ module to emulate a [SCSI] interface on your existing [IDE] [CDROM] drive. Add the following entries to your __/etc/modules.conf__:

 alias       scd0   sr_mod               # load sr_mod upon access of scd0
 pre-install sr_mod modprobe -k ide-scsi # load ide-scsi before sr_mod
 pre-install sg     modprobe -k ide-scsi # load ide-scsi before sg

In [Debian] [Woody], these go into __/etc/modutils/scsi__. Running __update-modules__ will copy them into __/etc/modules.conf__.

!! Device files

__/dev/sr''X''__ is the device generally used for [SCSI] [CDROM] support. On Linux, the device files are normally called __/dev/scd''X''__, and the __sr''X''__ devices are [SymLink]s. To set them all up automatically, do

 # cd /dev && ./MAKEDEV sr

If you want to always use the __ide-scsi__ emulation, make __/dev/cdrom__ a symlink to __/dev/sr0__ and make sure __/etc/fstab__ uses __/dev/cdrom__ instead of __/dev/hd''X''__.



If you make ide-cd and ide-scsi both modules, you can change how the CD-ROM drive is accessed without rebooting, depending on which module is currently loaded.

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CategoryKernel
One page links to SCSI-IDENotes:
CDWritingNotes
Last edited on Monday, August 23, 2004 2:00:10 pm by PerryLorier
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