8.4. Installing a Kernel with Support for up to 4GB RAM and Multi-Processors[id=smp]
Due to the limited amount of space available on one CD, there is only one Linux kernel available on the Skolelinux/Debian-edu CD. So, the chosen Linux kernel is based on the lowest common denominator, which means that it should work on most kinds of hardware.
You can find out what kind of kernel you are running at the moment with the command uname -a, use this command later to verify that you have changed to a different kernel, if you choose to do so.
If you want a kernel for the newer servers with plenty of RAM and multi-processors, you must download and install it afterward, which thanks to the genius package system of Debian, is very easy to do.
Have a look at Section 8.9 for a more detailed description of apt-get and dpkg.
The keyword to look for when you want a Linux kernel with support for more RAM than LOWMEM=940M and more than one CPU, is SMP, aka Symmetric Multi-Processors. This command issued from a shell, will list available Linux kernels, ready for installation:
apt-cache search kernel-image|grep smp
At the time this is being written, this returns:kernel-image-2.4.18-1-686-smp - Linux kernel image 2.4.18 on PPro/Celeron/PII/PIII/PIV SMP. kernel-image-2.4.16-686-smp - Linux kernel image 2.4.16 on PPro/Celeron/PII/PIII SMP. kernel-image-2.4.18-686-smp - Linux kernel image 2.4.18 on PPro/Celeron/PII/PIII/PIV SMP. kernel-image-2.4-686-smp - Linux kernel image for version 2.4 on PPro/Celeron/PII/PIII/PIV SMP. kernel-image-2.4-k7-smp - Linux kernel image for version 2.4 on AMD K7 SMP. kernel-image-2.4.26-1-686-smp - Linux kernel image for version 2.4.26 on PPro/Celeron/PII/PIII/PIV SMP. kernel-image-2.4.26-1-k7-smp - Linux kernel image for version 2.4.26 on AMD K7 SMP.There is really no reason not to choose the latest available kernel, in this case, version 2.4.26. You are then left with the following choices:
kernel-image-2.4.26-1-686-smp - Linux kernel image for version 2.4.24 on PPro/Celeron/PII/PIII/PIV SMP. kernel-image-2.4.26-1-k7-smp - Linux kernel image for version 2.4.24 on AMD K7 SMP.You can choose kernel-image-2.4.26-1-686-smp if you have an Intel processor (keyword is 686). If you have an AMD processor (keyword is k7) you can choose kernel-image-2.4.26-1-k7-smp.
Once you know which kernel is the correct one for your machine, you can install it with the command
apt-get install kernel-image-2.4.26-1<your cpu>
 | Some prefer to first download the kernel, and then install it manually with dpkg. See Section 8.9.9. apt-get install kernel-image-2.4.26-1<your cpu>-smp --download-only |
When you install the new kernel, you may see something like this:
Sætter kernel-image-2.4.26-1-k7 (2.4.24-3) op... You are attempting to install a kernel version that is the same as the version you are currently running (version 2.4.26-1-k7). The modules list is quite likely to have been changed, and the modules dependency file /lib/modules/2.4.26-1-k7/modules.dep needs to be re-built. It can not be built correctly right now, since the module list for the running kernel are likely to be different from the kernel installed. I am creating a new modules.dep file, but that may not be correct. It shall be regenerated correctly at next reboot. I repeat: you have to reboot in order for the modules file to be created correctly. Until you reboot, it may be impossible to load some modules. Reboot as soon as this installation is finished (Do not reboot right now, since you may not be able to boot back up until installation is over, but boot immediately after). I cannot stress that too much. You need to reboot soon. Please hit Return to continue.Here there is nothing else to do but hit ENTER to continue.
After you have installed a SMP-enabled kernel, and have rebooted your machine, you can use these commands to see if the newly-installed kernel sees all of your processors and RAM;
free
cat /proc/cpuinfo