# change hostname
hostnamectl set-hostname HOSTNAME# bash update system
yum install -y epel-release
yum update -y# bash auto command
yum install -y bash-completion bash-completion-extras
source /etc/profile.d/bash_completion.sh # bash install a minimal friendly set of programs
yum install -y setroubleshoot mc nano wget tcpdump net-tools git smartmontools mdadm # look list kernel core
rpm -q kernel# clean old kernal core --count=2 their number
package-cleanup --oldkernels --count=2