When you update CentOS and there is a new kernel CentOS will install the new kernel but not remove the old kernel, this can become problematic when you have a very small /boot partition so it is a good idea to remove the old kernels that are no longer needed. Please note that if you have a large /boot partition it is not necessary to delete the old kernels. Before deleting any of your old kernels make sure that you are booted onto the latest installed kernel. We can see the available space in the /boot mount by executing df -h /boot/ [root@centos]# df -h /boot/ Filesystem Size Used Avail Use%...