37.2. Preparing to Upgrade

Before upgrading the kernel, take a few precautionary steps. The first step is to make sure working boot media 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 Enterprise Linux without working boot media.

For example, to create a boot diskette, login as root, and type the following command at a shell prompt:

/sbin/mkbootdisk `uname -r`


Refer to the mkbootdisk man page for more options. Creating bootable media via CD-Rs, CD-RWs, and USB flash drives are also supported given the system BIOS also supports it.

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

Hopefully, the media is not 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 the system's architecture (the version numbers and packages may differ):


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. Refer to Section 37.1 Overview of Kernel Packages for descriptions of the different packages.

In the file name, each kernel package contains the architecture for which the package was built. The format is kernel-<variant>-<version>.<arch>.rpm, where <variant> is smp, utils, or so forth. The <arch> is one of the following: