Chapter 12: Kernel Management

The kernel is the core of the Linux operating system. The kernel controls such things as access to hardware, memory allocation, and so forth. This chapter discusses management of the kernel, including upgrading a kernel from Red Hat RPM packages and building a custom kernel. Ordinarily, it should not be necessary to install a new kernel manually. However, the administrator may wish to do so in cases where a new kernel release includes desired features not contained in the current 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, the kernel 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. The RPM package 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.)

Warning

Building your own custom kernel is not supported by the Red Hat Linux Installation Support Team.

The 2.4 Kernel

Red Hat Linux ships with a custom 2.4 kernel, which offers the following features:

• Kernel source directory is /usr/src/linux-2.4 instead of /usr/src/linux

• Support for the ext3 file system

• Multi-processor (SMP) support

• USB support

• Preliminary support for IEEE 1394, also referred to as FireWire, devices.