Centos 系统配置及优化

1. 更新国内源

# Backup Base and epel
[root@localhost ~]# mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
[root@localhost ~]# mv /etc/yum.repos.d/epel.repo /etc/yum.repos.d/epel.repo.backup
#  以下根据系统自选
curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-8.repo
curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo

2. 安装基础包

[root@localhost ~]# yum install -y gcc gcc-c++ make cmake net-tools httpd-tools wget vim tree htop \
iotop iftop lrzsz unzip telnet nmap nc psmisc dos2unix bash-completion sysstat \
lsof tcpdump bzip2 zip unzip bind-utils bash-completion-extras

3. 关闭firewalld && 关闭SELinux

[root@localhost ~]# setenforce 0 && sed -i "s/SELINUX=enforcing/SELINUX=disabled/g" /etc/selinux/config
[root@localhost ~]# systemctl stop firewalld.service && systemctl disable firewalld.service

4. 配置网络名称为eth0

[root@localhost ~]# vim /etc/sysconfig/grub
GRUB_CMDLINE_LINUX  # 追加 "net.ifnames=0"
[root@localhost ~]# grub2-mkconfig -o /boot/grub2/grub.cfg  #刷新内核
[root@localhost ~]# mv /etc/sysconfig/network-scripts/{ifcfg-ens32,ifcfg-eth0}  # 修改默认网卡名为eth0

[root@localhost ~]# cat >> /etc/sysconfig/network-scripts/ifcfg-eth0 << EOF  # 设置固定IP
IPADDR=10.0.0.10
GATEWAY=10.0.0.254
NETMASK=255.255.255.0
DNS1=223.5.5.5
EOF

5. SSH 连接速度优化

[root@localhost ~]# cat /etc/ssh/sshd_config |egrep "GSSAPIAuthentication|UseDNS"
GSSAPIAuthentication yes  # 修改前
UseDNS yes
[root@localhost ~]# sed -i 's/#UseDNS yes/UseDNS no/g;s/GSSAPIAuthentication yes/GSSAPIAuthentication no/g' /etc/ssh/sshd_config
[root@localhost ~]# cat /etc/ssh/sshd_config |egrep "GSSAPIAuthentication|UseDNS"
GSSAPIAuthentication no    # 修改后
UseDNS no
[root@localhost ~]# systemctl restart sshd