30.2. Preparing to Upgrade
Before upgrading the kernel, take a few precautionary steps. The first step is to make sure a working boot diskette exists for the system in case a problem occurs. If the boot loader is not configured properly to boot the new kernel, the system cannot be booted into Red Hat Linux without a working boot diskette.
To create the boot diskette, login as root at a shell prompt, and type the following command:
/sbin/mkbootdisk `uname -r` |
 | Tip |
|---|---|
Refer to the man page for mkbootdisk for more options. |
Reboot the machine with the boot diskette and verify that it works before continuing.
Hopefully, the diskette will not be needed, but store it in a safe place just in case.
To determine which kernel packages are installed, execute the following command at a shell prompt:
rpm -qa | grep kernel |
The output contains some or all of the following packages, depending on what type of installation was performed (the version numbers and packages may differ):
kernel-2.4.20-2.47.1 kernel-debug-2.4.20-2.47.1 kernel-source-2.4.20-2.47.1 kernel-doc-2.4.20-2.47.1 kernel-pcmcia-cs-3.1.31-13 kernel-smp-2.4.20-2.47.1 |
From the output, determine which packages need to be download for the kernel upgrade. For a single processor system, the only required package is the kernel package.
If the computer has more than one processor, the kernel-smp package that contains support for multiple processors must be installed for the system to use more than one processor. It is highly recommended that the kernel package also be installed in case the multi-processor kernel does not work properly for the system.
If the computer has more than four gigabytes of memory, the kernel-bigmem package must be installed for the system to use more than four gigabytes of memory. Again, it is highly recommended that the kernel package is installed for debugging purposes. The kernel-bigmem package is only built for the i686 architecture.
If PCMCIA support is needed (such as on a laptop), the kernel-pcmcia-cs package is necessary.
The kernel-source package is not needed unless a recompile of the kernel is desired or the system is used for kernel development.
The kernel-doc package contains kernel development documentation and is not required. It is recommended if the system is used for kernel development.
The kernel-util package includes utilities that can be used to control the kernel or the system's hardware. It 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 Intel® Pentium® II, Intel® Pentium® III, and Intel® Pentium® 4 systems, and i586 for Intel® Pentium® and AMD K6™ systems. If the version of the x86 system is unknown, 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-2.4.20-2.47.1.athlon.rpm is optimized for AMD Athlon™ and AMD Duron™ systems and kernel-2.4.20-2.47.1.i686.rpm is optimized for Intel® Pentium® II, Intel® Pentium® III, and Intel® Pentium® 4 systems. After determining which packages are needed to upgrade the kernel, select the proper architecture for the kernel, kernel-smp, and kernel-bigmem packages. Use the i386 versions of the other packages.