I have a hot-swap DVD/CDRW drive for my HP xt6050 laptop. I have spent quite some time on the internet to figure out how to make the drive real "hot-swap". And I found something on the Gentoo forum.

I need to load the modules in the following order:

scsi_mod 83876 2 [sr_mod ide-scsi]
ide-scsi 8752 0
cdrom 29504 0 (autoclean) [ide-cd sr_mod]
sr_mod 14392 0 (autoclean) (unused)
ide-cd 30036 0 (autoclean)

In gentoo, there's a file modules.autoload where I can specify the loading order. But in RH9, how do I do that?

Or is there any other way to make my hot-swap drive "hot-swap"? It's very annoying to have to reboot whenever I need to use the drive. (I usually don't have drive plugged in to make my laptop more portable. And after the suspend to ram, I lost the drive too)

Thanks

I think the file you're after is /etc/modules.conf (or /etc/conf.modules). Read the man page for it to learn how to use it; basically, it allows you to specify in detail which modules are loaded before which other modules.

Thanks wapcaplet, I read the manual, and found 2 methods:

1. Use OR Entry for these two:
[add] above module module_list
This directive makes it possible for one module to "pull in"
another set of modules on top of itself in a module stack, as
seen in the output of the lsmod(8) command. The above directive
is useful for those circumstances when the dependencies are more
complex than what can be described in the modules.dep dependency
file. This is an optimized case of the post-install and pre-
remove directives. Note that failure of installing the module
will not influence the exit status of modprobe. The optional
add prefix adds the new list to the previous list instead of
replacing it.

[add] below module module_list
This directive makes it possible for one module to "push"
another set of modules below itself in a module stack, as seen
in the output of the lsmod(8) command. The below directive is
useful for those circumstances when the dependencies are more
complex than what can be described in the modules.dep dependency
file. This is an optimized case of the pre-install and post-
remove directives. Note that failure of installing the module
will not influence the exit status of modprobe. The optional
add prefix adds the new list to the previous list instead of
replacing it.

Will they specify the order?

2. Use OR , then in rc.local modprobe in the order I want.

Are these two the methods you intent to show me? Coz my /etc/modules.conf only has some lines about the sound card and netword card, and nothing else. So I think there is a place where you specify what modules to load and their order.

Thanks

Hi...

I can suggest u the way in which i have loaded modules to my startup.

1. As written by you, arrange the modules to be loaded in the required sequence and create a file .......lets suppose u name it

'start_hotswap.sh'

2. Save this shell script in the directory

/usr/local/bin

3. Now open the rc.local file, go to the end and add the following line:

/usr/local/bin/start_hotswap.sh

4. Save the file and exit.

Now next time when u reboot, this script will be loaded automatically at the time of startup.

note - This may not be the most efficient way of getting files loaded at startup, but since i find this way easier and that does not need me to edit the /etc/modules.conf file, so i chose this way.

thanks

Actually what I had in mind was the pre-install, post-install and similar commands. Ex:

pre-install ide-scsi insmod scsi_mod

will load scsi_mod before loading ide-scsi. Though, in my experience, modprobe usually takes care of that stuff for you. Now that I look at your list of modules, it looks more like a simple dependency issue. Since ide-scsi depends on scsi_mod, scsi_mod must be loaded first. Apparently ide-cd depends on all of the previous ones.

What happens if you simply type "modprobe ide-cd"? If it doesn't work, try this (as root):

cd /lib/modules/`uname -r`
depmod -ae

Then try modprobe again. It ought to work; if not, maybe the pre-install commands and such will help you out. Good luck!

Thanks, wapcaplet and coolamit78.

I finally figured out the problem. It is not the order that matters. It is the stupid "updating /etc/fstab" thing. If I boot my laptop without the cdrom drive, it will delete my cdrom mount entry in /etc/fstab and won't load scisi emulation, thus I have no devices in /dev to mount even though I plug in the drive later.

Now I just make the /etc/fstab not writable. Is there another way telling the system not to update /etc/fstab every time I boot?

Thanks for all your help.