Centos7升级内核

#安装 ELRepo 仓库
rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-2.el7.elrepo.noarch.rpm
#查看内核
yum --disablerepo="*" --enablerepo="elrepo-kernel" list available
#安装主分支内核
yum --enablerepo=elrepo-kernel install kernel-ml
#修改grub，是默认启动新内核
cat /boot/grub2/grub.cfg |grep menuentry
#使用grub2-set-default命令，将新内核设为启动菜单。注意替换
grub2-set-default  'CentOS Linux (5.7.9-1.el7.elrepo.x86_64) 7 (Core)'