[techtalk] ide-scsi emulation

[Almut Behrens]

On Tue, Jul 24, 2001 at 11:15:46PM -0400, Raven Brooke wrote:
> 
> Anyone have an idea how to reverse this process? I followed some fairly
> simple directions to set it up, without recompiling the kernel, and all
> was well 'til I upgraded to RH 7.1. Now I seem to have _both_ cd devices
> emulating scsi, as revealed by scanbus:
>
> <snip>
> 
> This doesn't present a problem for recording, but I am unable to mount my
> cdrom. Be nice if I could return the cdrom to normal. None of the sources
> I've managed to turn up searching have been helpful in this regard.

...seems like the upgrading process left something in an inconsistent
state ;)

In addition to what Julie said, a few other things to investigate:

* what does /etc/fstab contain?
  (the cdrom entry might not have been updated properly)

* where is the symlink /dev/cdrom pointing to?

* what is showing up under /proc/scsi and/or /proc/ide?
  (i.e. which directories/files exist and what do they contain)

* what is the bootlog saying WRT your ide/scsi devices?
  (try dmesg, /var/log/boot.msg, (var/log/boot.log, /var/log/dmesg,
  /var/log/kern.log, or whichever you have...)

* can you mount the cdrom using "mount -t iso9660 /dev/scd0 /cdrom"?
  ("scd0" might be "scd1" or something else, see bootlog)

Also, in scsi emulation drivers for older kernels (2.0,2.2), there was a
lilo option to tell which devices to emulate (don't know if this still
holds for 2.4 -- YMMV). I think that's now in modules.conf. Still, you
might want to check for something like the following in /etc/lilo.conf

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

(where hd[abcd] depends on which ide bus the device(s) are connected to
physically and whether they're configured master/slave)

Generally, I believe there should be no problem accessing the cdrom via
ATAPI/SCSI hostadapter emulation now, if the rest of the system feels
that this is the appropriate form of doing it (i.e. you shouldn't need
to revert to using the old ide driver). Things just need to be
configured consistently the one or the other way.

Good luck!

- Almut