由于centos7停止维护，部分主机商停止提供，又或者不想要主机商预制的系统，由于centos7特殊性无法自动网络重装这里写一下手动重装的方法。
下载网络启动包
mkdir /boot/centos7/ cd /boot/centos7/ wget https://mirrors.huaweicloud.com/centos/7/os/x86_64/isolinux/vmlinuz wget https://mirrors.huaweicloud.com/centos/7/os/x86_64/isolinux/initrd.img
修改timeout=5555 增加启动项时间
nano /etc/default/grub
编辑文件 注意文件内的IP地址需要填写正确
nano /etc/grub.d/40_custom
menuentry "Install centos7" {
set root=(hd0,1)
linux /boot/centos7/vmlinuz headless ip=192.168.123.119 netmask=255.255.255.0 gateway=192.168.123.1 dns=8.8.8.8 ksdevice=eth0 method=https://mirrors.huaweicloud.com/centos/7/os/x86_64/ lang=en_US keymap=us
initrd /boot/centos7/initrd.img
}
更新grub 输入reboot 去VNC 安装吧
update-grub reboot
另外再放个国外源地址 img.cs.montana.edu
启动后缺少源
curl -o /etc/yum.repos.d/CentOS-Base.repo https://repo.huaweicloud.com/repository/conf/CentOS-7-reg.repo yum clean all & yum makecache
查看当前源
yum repolist
备份源
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
其他阿里云和腾讯云 如需wget 把curl -o 改成wget -O 注意O是大写的curl命令中是小写的
curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.cloud.tencent.com/repo/centos7_base.repo
升级内核为最后一个版本
wget https://mirrors.coreix.net/elrepo-archive-archive/kernel/el7/x86_64/RPMS/kernel-ml-6.9.7-1.el7.elrepo.x86_64.rpm wget https://mirrors.coreix.net/elrepo-archive-archive/kernel/el7/x86_64/RPMS/kernel-ml-devel-6.9.7-1.el7.elrepo.x86_64.rpm wget https://mirrors.coreix.net/elrepo-archive-archive/kernel/el7/x86_64/RPMS/kernel-ml-headers-6.9.7-1.el7.elrepo.x86_64.rpm wget https://mirrors.coreix.net/elrepo-archive-archive/kernel/el7/x86_64/RPMS/kernel-ml-tools-libs-6.9.7-1.el7.elrepo.x86_64.rpm wget https://mirrors.coreix.net/elrepo-archive-archive/kernel/el7/x86_64/RPMS/kernel-ml-tools-6.9.7-1.el7.elrepo.x86_64.rpm wget https://mirrors.coreix.net/elrepo-archive-archive/kernel/el7/x86_64/RPMS/kernel-ml-tools-libs-devel-6.9.7-1.el7.elrepo.x86_64.rpm wget https://mirrors.coreix.net/elrepo-archive-archive/kernel/el7/x86_64/RPMS/kernel-ml-doc-6.9.7-1.el7.elrepo.noarch.rpm yum install perl-Data-Dumper yum remove kernel-tools-libs-3.10.0-1160.el7.x86_64 rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org rpm -Uvh kernel-ml-6.9.7-1.el7.elrepo.x86_64.rpm rpm -Uvh kernel-ml-devel-6.9.7-1.el7.elrepo.x86_64.rpm rpm -Uvh kernel-ml-headers-6.9.7-1.el7.elrepo.x86_64.rpm rpm -Uvh kernel-ml-tools-libs-6.9.7-1.el7.elrepo.x86_64.rpm rpm -Uvh kernel-ml-tools-6.9.7-1.el7.elrepo.x86_64.rpm rpm -Uvh kernel-ml-tools-libs-devel-6.9.7-1.el7.elrepo.x86_64.rpm rpm -Uvh kernel-ml-doc-6.9.7-1.el7.elrepo.noarch.rpm rpm -qa | grep kernel egrep ^menuentry /etc/grub2.cfg | cut -f 2 -d \' grub2-set-default 0 grub2-mkconfig -o /boot/grub2/grub.cfg reboot uname -r
开启BBR
echo 'net.core.default_qdisc=fq' | sudo tee -a /etc/sysctl.conf echo 'net.ipv4.tcp_congestion_control=bbr' | sudo tee -a /etc/sysctl.conf sudo sysctl -p sysctl net.ipv4.tcp_available_congestion_control sysctl -n net.ipv4.tcp_congestion_control lsmod | grep bbr reboot
