Debian/Ubuntu/CentOS手动更换内核并开启BBR拥塞算法

说明

BBR 是 Google 开源的 TCP BBR 拥塞控制算法，用于提升网络连接速度，提升空间巨大，优化效果非常明显； BBR 仅支持4.9以上内核 Ubuntu 18.04 CentOS 8 Debian 9 均为4.9以上内核无需更换内核可以直接开启BBR；

脚本安装

如果不想手动更换可以使用以下一键脚本

BBR 一键脚本：https://sunpma.com/39.html

BBR2 一键脚本：https://sunpma.com/621.html

BBR BBRplus，BBR魔改 一键脚本：https://sunpma.com/37.html

内核版本查询：https://kernel.ubuntu.com/~kernel-ppa/mainline

安装内核

• 更新系统软件包到最新版

 apt update && apt upgrade -y

• 查看系统位数

 uname -m

执行后返回 x86_64 那就是64位系统；如果返回 i386或386或i686或686 那就是32位系统;

• 下载内核

 ## 64位系统：
 
 ## 4.17.0
 wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v4.17/linux-headers-4.17.0-041700_4.17.0-041700.201806041953_all.deb
 wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v4.17/linux-headers-4.17.0-041700-generic_4.17.0-041700.201806041953_amd64.deb
 wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v4.17/linux-image-unsigned-4.17.0-041700-generic_4.17.0-041700.201806041953_amd64.deb
 wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v4.17/linux-modules-4.17.0-041700-generic_4.17.0-041700.201806041953_amd64.deb
 
 ## 4.19.0
 wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.19/linux-headers-4.19.0-041900_4.19.0-041900.201810221809_all.deb
 wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.19/linux-headers-4.19.0-041900-generic_4.19.0-041900.201810221809_amd64.deb
 wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.19/linux-image-unsigned-4.19.0-041900-generic_4.19.0-041900.201810221809_amd64.deb
 wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.19/linux-modules-4.19.0-041900-generic_4.19.0-041900.201810221809_amd64.deb
 
 ## 5.2.4
 wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.2.4/linux-headers-5.2.4-050204_5.2.4-050204.201907280731_all.deb
 wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.2.4/linux-headers-5.2.4-050204-generic_5.2.4-050204.201907280731_amd64.deb
 wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.2.4/linux-image-unsigned-5.2.4-050204-generic_5.2.4-050204.201907280731_amd64.deb
 wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.2.4/linux-modules-5.2.4-050204-generic_5.2.4-050204.201907280731_amd64.deb
 
 ## 5.6.0
 wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.6/linux-headers-5.6.0-050600_5.6.0-050600.202003292333_all.deb
 wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.6/linux-headers-5.6.0-050600-generic_5.6.0-050600.202003292333_amd64.deb
 wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.6/linux-image-unsigned-5.6.0-050600-generic_5.6.0-050600.202003292333_amd64.deb
 wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.6/linux-modules-5.6.0-050600-generic_5.6.0-050600.202003292333_amd64.deb
 
 ## 32位系统：
 
 ## 4.19.0
 wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.19/linux-headers-4.19.0-041900_4.19.0-041900.201810221809_all.deb
 wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.19/linux-headers-4.19.0-041900-generic_4.19.0-041900.201810221809_i386.deb
 wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.19/linux-image-4.19.0-041900-generic_4.19.0-041900.201810221809_i386.deb
 wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.19/linux-modules-4.19.0-041900-generic_4.19.0-041900.201810221809_i386.deb

• 安装内核

 dpkg -i *.deb

• 更新grub系统引导文件

 update-grub

• 重启服务器

 reboot

• 重启后查看系统内核版本，确认是否安装成功

 uname -r

CentOS :

• 更换内核

 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
 
 yum --enablerepo=elrepo-kernel install kernel-ml -y

• 查看内核是否安装成功

 rpm -qa | grep kernel

• 更新grub系统引导文件

 egrep ^menuentry /etc/grub2.cfg | cut -f 2 -d \'
 
 grub2-set-default 0  #default 0表示第一个内核设置为默认运行, 选择最新内核就对了

• 重启服务器

 reboot

开启BBR

• 删除BBR

为了避免升级内核重复添加BBR开启代码，可以使用以下命令先删除一遍

 sed -i '/net\.core\.default_qdisc=fq/d' /etc/sysctl.conf
 
 sed -i '/net\.ipv4\.tcp_congestion_control=bbr/d' /etc/sysctl.conf

• 开启BBR

 echo "net.core.default_qdisc=fq" >> /etc/sysctl.conf
 
 echo "net.ipv4.tcp_congestion_control=bbr" >> /etc/sysctl.conf

• 使其生效

 sysctl -p

• 查看BBR是否开启成功

执行如下命令，如果返回值中有bbr即说明开启成功

 sysctl net.ipv4.tcp_congestion_control

执行如下命令，如果返回值中有tcp_bbr模块，即说明开启成功

 lsmod | grep bbr