After retrieving all of the necessary packages, it is time to upgrade the existing kernel.
It is strongly recommended that you keep the old kernel in case there are problems with the new kernel.
At a shell prompt, change to the directory that contains the kernel RPM packages. Use -i argument with the rpm command to keep the old kernel. Do not use the -U option, since it overwrites the currently installed kernel, which creates boot loader problems. For example:
rpm -ivh kernel-<kernel version>.<arch>.rpm
The next step is to verify that the initial RAM disk image has been created. Refer to Section 39.5, “Verifying the Initial RAM Disk Image” for details.