yum -y install http://mirror.cloud.idcsmart.com/cloud/kernel/5.4.166/kernel-lt-5.4.166-1.el7.elrepo.x86_64.rpm
grub2-set-default 'CentOS Linux (5.4.166-1.el7.elrepo.x86_64) 7 (Core)'
grub2-set-default 'CentOS Linux (5.4.166-1.el7.elrepo.x86_64) 7 (Core)'