Centos7 虚拟机优化

1. 配置yum源

   rm -f /etc/yum.repos.d/*
   curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
   curl -o /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo

2. 安装基础软件包

   yum install net-tools vim tree htop iftop gcc gcc-c++ glibc
   iotop lrzsz sl wget unzip telnet nmap nc psmisc 
   dos2unix bash-completion bash-completion-extra sysstat 
   rsync nfs-utils httpd-tools -y

3. 关闭防火墙firewalld

   systemctl disable firewalld
   systemctl stop firewalld

4. 关闭selinux

   sed -i '/^SELINUX=/c SELINUX=disabled' /etc/selinux/config

5. 调整单个进程最大能打开文件的数量

   echo '* - nofile 65535' >> /etc/security/limits.conf