Re: Should both my IDE CD drives use ide-scsi?
hi,
On Thu, Mar 28, 2002 at 01:57:58AM -0800, Bill Moseley wrote:
> Hello,
>
The magic works because cdrecord is actually looking for the /dev/sg*
devices. You have one /dev/sg for each scsi device on your system,
native SCSI or ide-scsi. And if you examine the configuration you'll see
that this is the key of the whole thing.
Try this:
strace -e trace=file cdrecord -scanbus
to convince your self.
You could also try
below sg ide-scsi sr_mod
instead of the pre-install line. It's nicer because the modules are then
automatically unloaded. You'll also not need the scd0 line anymore.
Ionut
> I assume this magic happens because of what I added to /etc/modutils/aliases (and thus to modules.conf after running update-modules):
>
> options ide-cd ignore=hdd # tell the ide-cd module to ignore hdd
> alias scd0 sr_mod # load sr_mod upon access of scd0 only
> pre-install sg modprobe ide-scsi # load ide-scsi before sg
> pre-install sr_mod modprobe ide-scsi # load ide-scsi before sr_mod
> # I've got ide-cd compiled in now
> #pre-install ide-scsi modprobe ide-cd # load ide-cd before ide-scsi
>
> I don't really see from man modules.conf why "alias scd0 sr_mod" makes that happen on demand. It makes sense that a device request to /dev/scd0 might trigger a kmod request. I guess I'm just missing something the modules.conf man page.
>
> My ide-cd is compiled in
>
> bumby:~# fgrep IDECD /boot/config-2.4.17-k7t266
> CONFIG_BLK_DEV_IDECD=y
>
> So I'm disabling ide for /dev/hdd in lilo.conf
>
> bumby:~# fgrep hdd /etc/lilo.conf
> append="apm=on apm=power-off hdd=ide-scsi"
>
> So the "options" line above doesn't seen necessary (as the pre-install I've commented out).
>
> That's the setup.
>
> So I wonder:
>
> 1) cdrecord -scanbus only shows one ide-scsi drive (/dev/hdd -- my CD-R). And also xcdroast only lists that one drive. Should I add hdc=ide-scsi to lilo.conf and run both my CD/DVD (/dev/hdc) and my CD-R as ide-scsi?
>
> 2) if I did run both as ide-scsi, would that change the way I need to access my CD/DVD drive? Currently I've got /dev/cdrom symlinked to /dev/hdc. Would I then need to link it to /dev/scd0 so things like xmms still work?
>
> Currently, in xmms in input plugin CD Audio Player's setup shows:
>
> Device: /dev/cdrom
> Directory: /cdrom
>
> If both /dev/hdc and /dev/hdd were ide-scsi would/could I say Device: /dev/hdc instead? Or would /dev/hdc no longer work if it was ide-scsi?
>
> 3) If I setup both CD drives as ide-scsi, then I suppose I need another "alias scd1 sr_mod" to auto-load modules on requests to that device, too. True?
>
> 4) the modules setup still confuses me. I don't really understand the reason for loading the modules on-demand instead of just loading them on boot or compiled in. If I had ide-cd as a module, could I unload ide-scsi and end up with just IDE CD drives again? And if so, what would be the reason for doing so? With 1/2G RAM I'm not really worried about a few 100K of memory the modules take up.
>
> 5) I suppose I need to set those on-demand modules as "autoclean" so they will unload?
>
> 6) Back to question 4, I wonder if there's even reason to bother with this on-demand loading and the settings in modules.conf these days (with so much RAM). Should I just load the ide-scsi support in an init.d script?
>
> 7) Finally, where does modconf fit in with all this? Is it part of the modules.conf setup, or just a front-end for selecting and loading modules. Where does it store what is loaded?
>
> Thanks very much -- especially if you made it this far!
>
> --
> Bill Moseley
>
>
> --
> To UNSUBSCRIBE, email to debian-user-request@lists.debian.org
> with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org
>
--
***************
* Ionut Georgescu
* http://www.physik.tu-cottbus.de/~george/
* Registered Linux User #244479
*
* "In Windows you can do everything Microsoft wants you to do; in Unix you
* can do anything the computer is able to do."
--
To UNSUBSCRIBE, email to debian-user-request@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org
Reply to: