centos 7 install mariadb code example

Example 1: centos 7 install iptables

sudo systemctl stop firewalld

sudo systemctl disable firewalld

sudo systemctl mask --now firewalld

sudo yum remove firewalld

sudo yum install iptables-services

sudo systemctl start iptables

sudo systemctl enable iptables

sudo systemctl status iptables

sudo iptables -nvL

Example 2: centos7 install grub

# yum reinstall grub2-efi grub2-efi-modules  shim