r1soft backup error : kernel header missing

Last day I’ve updated the kernel for the server to patch one of the major vulnerability and it causing the backup failure ( r1soft CDP backup ), in the detailed check, it is because of the kernel module for the r1soft cdp backup is missing. Inorder to make it work, we need to reinstall the CDP agent. And while trying to install the r1soft backup agent and we are getting the following error;

# serverbackup-setup --get-module
 Checking if module needs updated
 Checking for binary module
 Waiting /
 No binary module found
 Gathering kernel information
 Gathering kernel information complete.
 Creating kernel headers package
 Checking '/lib/modules/2.6.18-416.el5.centos.plus/source/' for kernel headers
 Checking '/usr/src/kernels/2.6.18-416.el5.centos.plus-i686/' for kernel headers
 Checking '/lib/modules/2.6.18-416.el5.centos.plus/build/' for kernel headers
 Unable to find a valid source directory.
 Please install the kernel headers for your operating system.

Mostly the error is due to missing of kernel devel. We can install the package kernel-devel using the following command

yum install kernel-devel

Once the kernel-devel is installed, please try the following command again

# serverbackup-setup --get-module