导入公钥
rpm--import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
安装yum源安装到centos7
rpm-Uvh http://www.elrepo.org/elrepo-release-7.0-2.el7.elrepo.noarch.rpm
安装内核（7的用kernel-ml）
yum--enablerepo=elrepo-kernelinstallkernel-ml
安装到centos6
rpm-Uvh http://www.elrepo.org/elrepo-release-6-6.el6.elrepo.noarch.rpm
安装到centos5
rpm-Uvh http://www.elrepo.org/elrepo-release-5-5.el5.elrepo.noarch.rpm
安装内核(5/6 的用kernel-lt)
yum--enablerepo=elrepo-kernelinstallkernel-lt
有时候网络问题导致
Nopackagekernel-ml*available. Error:Nothingtodo
那就手动下载rpm包，手动安装，指定启动顺序
wgethttp://elrepo.org/linux/kernel/el7/x86_64/RPMS/kernel-ml-4.6.4-1.el7.elrepo.x86_64.rpm
rpm-ivhkernel-ml-4.6.4-1.el7.elrepo.x86_64.rpm
grub2-set-default'CentOSLinux(4.4.2-1.el7.elrepo.x86_64)7(Core)withdebugging'
[root@abcboot]#grub2-editenvlist saved_entry=CentOSLinux(4.4.2-1.el7.elrepo.x86_64)7(Core)withdebugging原文链接：https://www.f2er.com/centos/381326.html
