Chapter 23. Upgrading the Kernel
The Red Hat Linux kernel is custom built by the Red Hat kernel team to ensure its integrity and compatibility with supported hardware. Before Red Hat releases a kernel, it must pass a rigorous set of quality assurance tests.
Official Red Hat Linux kernels are packaged in RPM format so that they are easy to upgrade and verify. For example, the kernel RPM package creates the initrd image; it is not necessary to use the mkinitrd command after installing a different kernel if you install the kernel from the Red Hat RPM package. It also modifies the boot loader configuration file to include the new kernel if either GRUB or LILO is installed. (You do need to set the new kernel as the default kernel to boot.)
This chapter discusses the steps necessary to upgrade the kernel on an x86 system only.
 | Warning |
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Building your own custom kernel is not supported by the Red Hat Linux Installation Support Team. For more information on building a custom kernel from the source code, refer to Appendix A. |
The 2.4 Kernel
Red Hat Linux ships with a custom 2.4 kernel, which offers the following features:
The directory for the kernel source is /usr/src/linux-2.4 instead of /usr/src/linux.
Support for the ext3 filesystem.
Multi-processor (SMP) support.
Support for up to 64 gigabytes of physical RAM — the kernel-bigmem package in Red Hat Linux 7.3 is compiled to support 64 gigabytes of physical memory.
USB support.
Preliminary support for IEEE 1394, also referred to as FireWireTM, devices.