How to Remove CentOS old kernels or CentOS freeing up disk space
1. Check currently list of installed Linux kernels with RPM command
#rpm -q kernel kernel-2.6.32-573.12.1.el6.i686 kernel-2.6.32-573.18.1.el6.i686 kernel-2.6.32-573.22.1.el6.i686 kernel-2.6.32-573.26.1.el6.i686 kernel-2.6.32-642.1.1.el6.i686
2. Install Install YUM Utilities Package
#yum install yum-utils
3. Remove old Linux kernels using yum-utils commands. package-cleanup utility will help you easly remove older Linux kernels.
# package-cleanup --oldkernels --count=2