CentOS内核升级

CentOS 7默认内核还在3.x版本，VMWARE虚拟机启动有报错信息出现，现更新版本，使用ELRepo-kernel源安装

1、添加源
Import the public key:
rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org

To install ELRepo for RHEL-8 or CentOS-8:
yum install https://www.elrepo.org/elrepo-release-8.el8.elrepo.noarch.rpm

To install ELRepo for RHEL-7, SL-7 or CentOS-7:
yum install https://www.elrepo.org/elrepo-release-7.el7.elrepo.noarch.rpm

2、安装最新稳定版（lt）本内核，使用enablerepo方式安装不要启用源，免得每次yum update都有提示！
yum --enablerepo=elrepo-kernel install kernel-lt

3、重启reboot

4、查看当前内核并设置默认新内核
awk -F' '$1"menuentry " {print $2}' /etc/grub2.cfg 查看当前已安装内核BIOS
awk -F' '$1"menuentry " {print $2}' /etc/grub2-efi.cfg EFI引导路径
awk -F' '$1=="menuentry " {print $2}' /boot/efi/EFI/centos/grub.cfg CentOS7路径

5、设置默认启动内核
grub2-set-default "CentOS Linux (5.4.191-1.el7.elrepo.x86_64) 7 (Core)"
grub2-set-default "CentOS Linux (3.10.0-1160.62.1.el7.x86_64) 7 (Core)"