Preparing to Upgrade

Before you upgrade your kernel, you must take a few precautionary steps. The first step is to make sure you have a working boot diskette for your system in case a problem occurs. If the boot loader is not configured properly to boot the new kernel, you will not be able to boot your system unless you have a boot diskette.

To create a boot diskette for your system, you need to determine which version of the kernel you are currently running. Execute the following command:

uname -r

You must be root to create a boot diskette for your system. Login as root at a shell prompt, and type the following command (where kernelversion is the output of the uname -r command):

/sbin/mkbootdisk kernelversion

	Tip
	Refer to the man page for mkbootdisk for more options.

Reboot your machine with the boot diskette and verify that it works before continuing.

Hopefully, you will not have to use the diskette, but you should store it in a safe place just in case.

To determine which kernel packages you have installed, execute the following command at a shell prompt:

rpm -qa | grep kernel

The output will contain some or all of the following packages, depending on what type of installation you performed (your version numbers and packages may differ):

kernel-2.4.18-7.95
kernel-debug-2.4.18-7.95
kernel-source-2.4.18-7.95
kernel-doc-2.4.18-7.95
kernel-pcmcia-cs-3.1.27-12
kernel-smp-2.4.18-7.95

From the output, you can determine which packages you need to download for the kernel upgrade. For a single processor system, the only required package is the kernel package.

If you have a computer with more than one processor, you need the kernel-smp package that contains support for multiple processors. It is recommended that you also install the kernel package in case the multi-processor kernel does not work properly for your system.

If you have a computer with more than four gigabytes of memory, you need the kernel-bigmem package. Again, it is recommended that you also install the kernel package for debugging purposes. The kernel-bigmem package is only built for the i686 architecture.

If you are upgrading the kernel on a laptop or are using PCMCIA, the kernel-pcmcia-cs package is also required.

You do not need the kernel-source package unless you plan to recompile the kernel yourself or plan to perform kernel development. The kernel-doc package contains kernel development documentation and is not required. The kernel-util package includes utilities that can be used to control the kernel or the system's hardware and is not required.

Red Hat builds kernels that are optimized for different x86 versions. The options are athlon for AMD Athlon™ and AMD Duron™ systems, i686 for IntelŪ PentiumŪ II, IntelŪ PentiumŪ III, and IntelŪ PentiumŪ 4 systems, and i586 for IntelŪ PentiumŪ and AMD K6™ systems. If you do not know the version of your x86 system, use the kernel built for the i386 version; it is built for all x86-based systems.

The x86 version of the RPM package is included in the file name. For example, kernel-2.4.18-7.95.athlon.rpm is optimized for AMD Athlon™ and AMD Duron™ systems and kernel-2.4.18-7.95.i686.rpm is optimized for IntelŪ PentiumŪ II, IntelŪ PentiumŪ III, and IntelŪ PentiumŪ 4 systems. When you have determined which packages you need to upgrade your kernel, select the proper architecture for the kernel, kernel-smp, and kernel-bigmem packages. Use the i386 versions of the other packages.