CentOS 8.0 安装 kernel 5.4.8 并开启BBR

今天，XX云总算是支持centos 8.0的镜像了，提前准备了N久的东西总算是可以用上了，先把内核搞一搞

kernel 5.4.7才开始支持centos 8.0系统，这次直接安装最新的5.4.8

# 先卸载原有的内核版本

# rpm -qa | grep kernel
kernel-core-4.18.0-80.11.2.el8_0.x86_64
kernel-tools-libs-4.18.0-80.11.2.el8_0.x86_64
kernel-headers-4.18.0-80.11.2.el8_0.x86_64
kernel-core-4.18.0-80.el8.x86_64
kernel-modules-4.18.0-80.el8.x86_64
kernel-modules-4.18.0-80.11.2.el8_0.x86_64
kernel-devel-4.18.0-80.11.2.el8_0.x86_64
kernel-tools-4.18.0-80.11.2.el8_0.x86_64
kernel-4.18.0-80.11.2.el8_0.x86_64
kernel-4.18.0-80.el8.x86_64

# rpm -e kernel-4.18.0-80.el8.x86_64

# rpm -e kernel-modules-4.18.0-80.el8.x86_64 kernel-core-4.18.0-80.el8.x86_64

# yum remove glibc-headers

# rpm -e kernel-headers-4.18.0-80.11.2.el8_0.x86_64

# rpm -e kernel-devel-4.18.0-80.11.2.el8_0.x86_64 kernel-tools-4.18.0-80.11.2.el8_0.x86_64

# rpm -e kernel-tools-libs-4.18.0-80.11.2.el8_0.x86_64

最后就剩三个

# 开始安装新内核

# rpm –import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org

# rpm -Uvh https://www.elrepo.org/elrepo-release-8.0-2.el8.elrepo.noarch.rpm

# yum –enablerepo=elrepo-kernel install kernel-ml kernel-ml-headers kernel-ml-tools kernel-ml-tools-libs -y

# grub2-set-default 0

# 然后重启服务器

# 设置BBR

# vim /etc/sysctl.conf

net.core.default_qdisc = fq
net.ipv4.tcp_congestion_control = bbr 

# sysctl -p

但是有个问题：

安装完内核之后，安装GCC提示需要kernel-headers-4.18.0-80.11.2.el8_0.x86_64，如果需求GCC的暂时就不要考虑升级内核到5.4.x了

如果还要用GCC，那么解决方法如下：

不卸载原有内核信息，只安装新内核，安装 kernel-ml 和 kernel-ml-devel

# yum –enablerepo=elrepo-kernel install kernel-ml kernel-ml-devel -y