Kernel Upgrade in Linux

To Update the kernel

Check the current version of kernel using following commands

1.      use  'uname -a' to reveal current version

2.      use  'rpm -qa | grep -i kernel' - to reveal installed version

3.      Use ‘rpm –qa’ kernel

4.      Use ‘lscpu’

5.      Use  'arch'   

Download the kernel update rpm

Change the directory to rpm download location

example:cd /Downlaods

The Proper installation/Upgrade method for kernel 

1.      'rpm -ivh kernel*.rpm'   - To install a separate version

Example:

rpm –ivh kernel*

                        or

yum install kernel*

Note: This will update GRUB (/boot/grub/grub.conf)
Note: Will also place the new kernel in the /boot file system
Examine the traces in,

1.      /boot

2.      /boot/grub/grub.conf

Now Remove traces of former kernel using 
'rpm -e [--nodeps]' kernel-2.6.18-8.el5  kernel-headers-2.6.18-8.el5 kernel-devel-2.6.18-8.el5’
To Force remove ignoring dependencies give,
'rpm -e --nodeps kernel-headers-2.6.18-8.el5’

Note: Removal of older kernel-* packages cleans up the /boot  and  /boot/grub/grub.conf   as well.

Verification

rpm -qa | grep kernel

rpm -qa kernel
arch