With Slackware 12.1 and KDE 3.5.9, I boot to the full GUI run level 4 or 5, and using only that huge SMP kernel, with no initial RAM disk. So if I do make a initrd, can I boot up with just the smaller generic kernel, and what is better when booting that way ? Is there a readme file for how to do that in the boot folder, right ? Also some kernels have a version with a "PAE" at the end, what is that ? Thanks for any help on this.

With the huge SMP kernel you *can* sometimes get into trouble, e.g. if two drivers claim the same device because as many drivers as possible are in this case "built-in", instead of compiled as modules. On the contrary, in the case of the generic kernel most drivers are compiled as modules. The main reason because you could need an initrd if you use a generic kernel is that as in this case most file systems are compiled as modules, in many cases you need to load at time of booting the driver for your root filesystem's root partition, otherwise you couldn't boot. For instance as I use reiserfs for my root partition I use a initrd wich is so to speak a bundle of the kernel and the reiserfs module.

By the way all that is explained in the file CHANGES_AND_HINTS.TXT at the top level of you installation CD and yes, you will find instructions for making and using an initrd in the file /boot/README.initrd

Sorry for my bad English, I'd better post in French next time

Yes, if you look in the /boot directory you will see the README.initrd that explains how to create an initrd.
You then have to edit lilo.conf to boot the generic kernel and then rerun lilo.

Well I see then, and thanks for the replies. So if I need that other type of kernel, (the generic smaller one), I can install it from either my DVD or with the built in package tool or that slackpkg tool, right ?

If you did a full install of Slackware, or at least if you installed everything from the a/ series:
http://slackware.oregonstate.edu/sla...2/slackware/a/
...then you already have the generic kernels installed. If not, then yes, you can install the generic kernels from the Slackware DVD with pkgtool. As per the Slackware Changes and Hints.txt you should run the generic-smp kernel unless you have a specific reason to not use the smp kernel.

If you are not sure whether or not you installed the generic kernels, just look for them listed in your /var/log/packages directory or find the kernels in your /boot directory.

I did follow the initial ram disk readme file steps to create a initrd, and then made the changes in my main grub boot menu file, and it booted up just fine. Yes right, I did have all the kernels installed from my full default Slackware install, (2 generic, and 2 huge). I did not really notice any thing different during the boot and load process with initrd. So should it be faster to GUI desktop, and use less system memory too ?

You can try, just keep two entries in Grub, one for the huge-smp and one for the generic-smp.

I do not expect you will find a noticeable difference in memory usage unless you blacklist a lot of "heavy" modules -- but some applications are a lot more memory hungry than the kernel itself anyway.

You should not see any speed difference with GUI desktop either.

As far as I know, the main advantage is the ability you get to choose the driver which will be loaded for a specific device, thus avoiding problems such as the same device claimed by different drivers.

initrd is required only if you don't want to compile required modules into kernel. "required modules" mean root filesystem support, maybe something hardware-specific, etc. I believe it is also required if root partition is encrypted. If this is not your case, you don't have to use initrd.