# 启用 ELRepo
dnf -y install elrepo-release
#or
yum -y install elrepo-release

# 安装ELRepo 9
dnf install https://www.elrepo.org/elrepo-release-9.el9.elrepo.noarch.rpm

# 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
# To make use of our mirror system, **please also install yum-plugin-fastestmirror**.

# 列出可用的内核相关包：
yum --disablerepo="*" --enablerepo="elrepo-kernel" list available
yum --disablerepo="*" --enablerepo="elrepo-kernel" list available --showduplicates #查看所有版本
# 安装
dnf --disablerepo=\* --enablerepo=elrepo-kernel install -y kernel-ml.x86_64
sudo dnf --enablerepo=elrepo-kernel install kernel-lt kernel-lt-devel kernel-lt-headers -y
# 删除旧版本工具包
dnf remove kernel-tools-libs.x86_64 kernel-tools.x86_64


# 使用grub确认、修改启动项
grub2-editenv list
grub2-set-default 0

# grubby centos8后内置的命令行工具，用于更新和显示有关 grub2 和 zipl 引导加载程序的配置文件的信息
grubby --default-kernel
grubby --info=ALL
grubby --info=/boot/vmlinuz-4.18.0-348.el8.x86_64
grubby --set-default=/boot/vmlinuz-4.18.0-348.el8.x86_64
grubby --set-default-index=1
grubby --remove-kernel=/boot/vmlinuz-4.18.0-348.el8.x86_64