1、导入密钥

rpm--importhttps://www.elrepo.org/RPM-GPG-KEY-elrepo.org

2、添加库

#Centos7
rpm-Uvhhttp://www.elrepo.org/elrepo-release-7.0-2.el7.elrepo.noarch.rpm
#Centos6
rpm-Uvhhttp://www.elrepo.org/elrepo-release-6-8.el6.elrepo.noarch.rpm

3、更新内核

yum--enablerepo=elrepo-kernelinstallkernel-ml

4、查询所有内核列表

#Centos7
grep-oP"(?<=^menuentry\')[^\']+"/etc/grub2.cfg
#Centos6
grep-oP'(?<=title).*'/boot/grub/grub.conf

5、修改默认启动内核

#Centos7
grub2-set-default"CentOSLinux(4.12.4-1.el7.elrepo.x86_64)7(Core)"
#Centos6
sed-i's/^default=.*/default=0/g'/boot/grub/grub.conf

6、重启

reboot

7、查看内核版本

uname-r