##記得切換到root用戶執行升級操作.
[root@centos ~]# uname -a ##舊版
Linux centos 2.6.32-642.el6.x86_64 #1 SMP Tue May 10 17:27:01 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
[root@localhost ~]# rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
[root@centos ~]# rpm -ivh http://www.elrepo.org/elrepo-release-6-8.el6.elrepo.noarch.rpm
Retrieving http://www.elrepo.org/elrepo-release-6-8.el6.elrepo.noarch.rpm
Preparing... ########################################### [100%]
1:elrepo-release ########################################### [100%]
[root@localhost ~]# yum --enablerepo=elrepo-kernel install kernel-lt -y ##此步會有點慢
[root@localhost ~]# vim /etc/grub.conf default=1 改爲 default=0 ##設置默認以3.10核心啓動，默認是按照舊的核心啓動
[root@localhost ~]# reboot
[root@centos ~]# uname -a ##升級後的版本
Linux centos 4.4.131-1.el6.elrepo.x86_64 #1 SMP Wed May 2 14:51:15 EDT 2018 x86_64 x86_64 x86_64 GNU/Linux