1、下载新的 rpm内核包：

wget http://mirrors.coreix.net/elrepo-archive-archive/kernel/el7/x86_64/RPMS/kernel-lt-devel-5.4.226-1.el7.elrepo.x86_64.rpm

wget http://mirrors.coreix.net/elrepo-archive-archive/kernel/el7/x86_64/RPMS/kernel-lt-headers-5.4.226-1.el7.elrepo.x86_64.rpm

wget http://mirrors.coreix.net/elrepo-archive-archive/kernel/el7/x86_64/RPMS/kernel-lt-5.4.226-1.el7.elrepo.x86_64.rpm

备注：当前在那个目录，rpm包就会下载到哪个目录。

2、安装内核：

rpm -ivh kernel-lt-5.4.226-1.el7.elrepo.x86_64.rpm

3、更新 GRUB 配置：

grub2-mkconfig -o /boot/grub2/grub.cfg

返回如下内容：

Generating grub configuration file ...
Found linux image: /boot/vmlinuz-5.4.226-1.el7.elrepo.x86_64
Found initrd image: /boot/initramfs-5.4.226-1.el7.elrepo.x86_64.img
Found linux image: /boot/vmlinuz-3.10.0-1127.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-1127.el7.x86_64.img
Found linux image: /boot/vmlinuz-0-rescue-b7891fc9f791fa438afe9bcdcfa70ff5
Found initrd image: /boot/initramfs-0-rescue-b7891fc9f791fa438afe9bcdcfa70ff5.img

4、设置默认内核：

grubby --set-default=/boot/vmlinuz-5.4.226-1.el7.elrepo.x86_64

5、重启系统：

reboot

6、验证新内核：

uname -r