Understanding SUSE Kernel Backgrounds

The kernels that are used on SUSE Linux (no matter what version of the operating system you are using) are generated from the "vanilla" kernel sources. These are the open source kernel sources because they are produced from the kernel project. On top of these sources, a number of patches are applied. The result of this is a SUSE-specific kernel source tree that is built and compiled to the binary configuration file /boot/vmlinuz. On SUSE Linux Enterprise Server, you will always find a number of binary kernels. These are kernels that are complete for usage on specific hardware platforms, such as a 32-bit or 64-bit platform. When installing SUSE Linux Enterprise Server on a specific hardware platform, the right binary kernel is installed automatically, so for the administrator this is an entirely transparent process.

Some situations may require that the kernel sources are present. This is mainly the case if you need to be able to add new functionality to the kernel, for example to compile a module for a certain piece of hardware for which you have only the source code and no compiled version. In that situation, you need the kernel sources present on your server. When installing the kernel source's RPM package from YaST, a directory structure that contains the kernel sources is created in /usr/ src. The most important directory you'll find here is the Linux directory, which is a symbolic link pointing to the directory that contains the source files of the current kernel.

As an administrator, from the kernel sources, you can create your own binary kernel. This is referred to as compiling the kernel. Compiling the kernel is a five-step procedure:

1. Use YaST to install the kernel sources for your platform. For example, if you are using i386, install the kernel-source.i386.rpm package from the installation media. Next, make /usr/ src/Linux your current directory.

Caution Work with the kernel sources only as provided by Novell with SUSE Linux Enterprise Server. Downloading and installing kernel sources from ftp.kernel.org may break functionality on your server!

2. Configure the kernel. You can find more information about this in the next section.

3. Build the kernel and all its modules. To do this, you can use the make command. This will start the kernel compilation. Be aware that it can take a long time (from about 10 to 15 minutes on fast systems to many hours on slow systems) before this resource-intensive process completes.

4. After compiling the kernel, you must install the new kernel and its modules. Do this by first running make modules_install and next make install. Don't bother about making an initrd as well; these commands will do that for you automatically.

5. Add the new kernel to the boot manager.

Was this article helpful?

0 0

Post a comment