CentOS 7 system optimization script

1. Introduction

As an operation and maintenance person, we often deploy operating systems for various purposes. However, in these tasks, we will find that many tasks are actually repetitive labor, and the content of the operations is similar. Based on this type of work, In this case, we can make the same operation into a script for unified execution, and different things can be entered manually as variables. Can’t the time saved be used to do more meaningful things?

Recently, I found a relatively easy-to-use shell source code based on the recommendation of fans. I adapted it based on this and shared it with everyone.

2. Menu

Main menu:

Secondary menu:

# Mainly realizes various optimizations of the system, such as commonly used functions such as modifying character sets, turning off selinux, turning off firewalls, installing commonly used tools, and accelerating SSH login. .

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3. Source code

#!/bin/sh

. /etc/rc.d/init.d/functions
export LANG=zh_CN.UTF-8

#一级菜单
menu1()
{
        clear
        cat <<eof
----------------------------------------
|****   欢迎使用cetnos7.9优化脚本    ****|
|****      博客地址: aaa.al         ****|
----------------------------------------
1. 一键优化
2. 自定义优化
3. 退出
EOF
        read -p "please enter your choice[1-3]:" num1
}

#二级菜单
menu2()
{
 clear
 cat <<eof
----------------------------------------
|****Please Enter Your Choice:[0-13]****|
----------------------------------------
1. 修改字符集
2. 关闭selinux
3. 关闭firewalld
4. 精简开机启动
5. 修改文件描述符
6. 安装常用工具及修改yum源
7. 优化系统内核
8. 加快ssh登录速度
9. 禁用ctrl+alt+del重启
10.设置时间同步
11.history优化
12.返回上级菜单
13.退出
EOF
 read -p "please enter your choice[1-13]:" num2

}

#1.修改字符集
localeset()
{
 echo "========================修改字符集========================="
 cat > /etc/locale.conf <<eof
LANG="zh_CN.UTF-8"
#LANG="en_US.UTF-8"
SYSFONT="latarcyrheb-sun16"
EOF
 source /etc/locale.conf
 echo "#cat /etc/locale.conf"
 cat /etc/locale.conf
 action "完成修改字符集" /bin/true
 echo "==========================================================="
 sleep 2
}

#2.关闭selinux
selinuxset()
{
 selinux_status=`grep "SELINUX=disabled" /etc/sysconfig/selinux | wc -l`
 echo "========================禁用SELINUX========================"
 if [ $selinux_status -eq 0 ];then
  sed  -i "s#SELINUX=enforcing#SELINUX=disabled#g" /etc/sysconfig/selinux
  setenforce 0
  echo &#39;#grep SELINUX=disabled /etc/sysconfig/selinux&#39;
  grep SELINUX=disabled /etc/sysconfig/selinux
  echo &#39;#getenforce&#39;
  getenforce
 else
  echo &#39;SELINUX已处于关闭状态&#39;
  echo &#39;#grep SELINUX=disabled /etc/sysconfig/selinux&#39;
                grep SELINUX=disabled /etc/sysconfig/selinux
                echo &#39;#getenforce&#39;
                getenforce
 fi
  action "完成禁用SELINUX" /bin/true
 echo "==========================================================="
 sleep 2
}

#3.关闭firewalld
firewalldset()
{
 echo "=======================禁用firewalld========================"
 systemctl stop firewalld.service &> /dev/null
 echo &#39;#firewall-cmd  --state&#39;
 firewall-cmd  --state
 systemctl disable firewalld.service &> /dev/null
 echo &#39;#systemctl list-unit-files | grep firewalld&#39;
 systemctl list-unit-files | grep firewalld
 action "完成禁用firewalld，生产环境下建议启用！" /bin/true
 echo "==========================================================="
 sleep 5
}

#4.精简开机启动
chkset()
{
 echo "=======================精简开机启动========================"
 systemctl disable auditd.service
 systemctl disable postfix.service
 systemctl disable dbus-org.freedesktop.NetworkManager.service
 echo &#39;#systemctl list-unit-files | grep -E "auditd|postfix|dbus-org\.freedesktop\.NetworkManager"&#39;
 systemctl list-unit-files | grep -E "auditd|postfix|dbus-org\.freedesktop\.NetworkManager"
 action "完成精简开机启动" /bin/true
 echo "==========================================================="
 sleep 2
}

#5.修改文件描述符
limitset()
{
 echo "======================修改文件描述符======================="
 echo &#39;* - nofile 65535&#39;>/etc/security/limits.conf
 ulimit -SHn 65535
 echo "#cat /etc/security/limits.conf"
 cat /etc/security/limits.conf
 echo "#ulimit -Sn ; ulimit -Hn"
 ulimit -Sn ; ulimit -Hn
 action "完成修改文件描述符" /bin/true
 echo "==========================================================="
 sleep 2
}

#6.安装常用工具及修改yum源
yumset()
{
 echo "=================安装常用工具及修改yum源==================="
 yum install wget -y &> /dev/null
 if [ $? -eq 0 ];then
  cd /etc/yum.repos.d/
  \cp CentOS-Base.repo CentOS-Base.repo.$(date +%F)
  ping -c 1 mirrors.aliyun.com &> /dev/null
  if [ $? -eq 0 ];then
   wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo &> /dev/null
   yum clean all &> /dev/null
   yum makecache &> /dev/null
  else
   echo "无法连接网络"
       exit $?
    fi
 else
  echo "wget安装失败"
  exit $?
 fi
 yum -y install ntpdate lsof net-tools telnet vim lrzsz tree nmap nc sysstat &> /dev/null
 action "完成安装常用工具及修改yum源" /bin/true
 echo "==========================================================="
 sleep 2
}

#7. 优化系统内核 #另外，搜索公众号技术社区后台回复“壁纸”，获取一份惊喜礼包。kernelset()
{
 echo "======================优化系统内核========================="
 chk_nf=`cat /etc/sysctl.conf | grep conntrack |wc -l`
 if [ $chk_nf -eq 0 ];then
  cat >>/etc/sysctl.conf<<eof
net.ipv4.tcp_fin_timeout = 2
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_keepalive_time = 600
net.ipv4.ip_local_port_range = 4000 65000
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.tcp_max_tw_buckets = 36000
net.ipv4.route.gc_timeout = 100
net.ipv4.tcp_syn_retries = 1
net.ipv4.tcp_synack_retries = 0
net.core.somaxconn = 16384
net.core.netdev_max_backlog = 16384
net.ipv4.tcp_max_orphans = 16384
net.netfilter.nf_conntrack_max = 25000000
net.netfilter.nf_conntrack_tcp_timeout_established = 180
net.netfilter.nf_conntrack_tcp_timeout_time_wait = 120
net.netfilter.nf_conntrack_tcp_timeout_close_wait = 60
net.netfilter.nf_conntrack_tcp_timeout_fin_wait = 120
EOF
 sysctl -p
 else
  echo "优化项已存在。"
 fi
 action "内核调优完成" /bin/true
 echo "==========================================================="
 sleep 2
}

#8.加快ssh登录速度
sshset()
{
 echo "======================加快ssh登录速度======================"
 sed -i &#39;s#^GSSAPIAuthentication yes$#GSSAPIAuthentication no#g&#39; /etc/ssh/sshd_config
 sed -i &#39;s/#UseDNS yes/UseDNS no/g&#39; /etc/ssh/sshd_config
 systemctl restart sshd.service
 echo "#grep GSSAPIAuthentication /etc/ssh/sshd_config"
 grep GSSAPIAuthentication /etc/ssh/sshd_config
 echo "#grep UseDNS /etc/ssh/sshd_config"
 grep UseDNS /etc/ssh/sshd_config
 action "完成加快ssh登录速度" /bin/true
 echo "==========================================================="
 sleep 2
}

#9. 禁用ctrl+alt+del重启
restartset()
{
 echo "===================禁用ctrl+alt+del重启===================="
 rm -rf /usr/lib/systemd/system/ctrl-alt-del.target
 action "完成禁用ctrl+alt+del重启" /bin/true
 echo "==========================================================="
 sleep 2
}

#10. 设置时间同步
ntpdateset()
{
 echo "=======================设置时间同步========================"
 yum -y install ntpdate &> /dev/null
 if [ $? -eq 0 ];then
  /usr/sbin/ntpdate time.windows.com
  echo "*/5 * * * * /usr/sbin/ntpdate ntp.aliyun.com &>/dev/null" >> /var/spool/cron/root
 else
  echo "ntpdate安装失败"
  exit $?
 fi
 action "完成设置时间同步" /bin/true
 echo "==========================================================="
 sleep 2
}

#11. history优化
historyset()
{
 echo "========================history优化========================"
 chk_his=`cat /etc/profile | grep HISTTIMEFORMAT |wc -l`
 if [ $chk_his -eq 0 ];then
  cat >> /etc/profile <<&#39;EOF&#39;
#设置history格式
export HISTTIMEFORMAT="[%Y-%m-%d %H:%M:%S] [`whoami`] [`who am i|awk &#39;{print $NF}&#39;|sed -r &#39;s#[()]##g&#39;`]: "
#记录shell执行的每一条命令
export PROMPT_COMMAND=&#39;\
if [ -z "$OLD_PWD" ];then
    export OLD_PWD=$PWD;
fi;
if [ ! -z "$LAST_CMD" ] && [ "$(history 1)" != "$LAST_CMD" ]; then
    logger -t `whoami`_shell_dir "[$OLD_PWD]$(history 1)";
fi;
export LAST_CMD="$(history 1)";
export OLD_PWD=$PWD;&#39;
EOF
  source /etc/profile
 else
  echo "优化项已存在。"
 fi
 action "完成history优化" /bin/true
 echo "==========================================================="
 sleep 2
}

#控制函数
main()
{
 menu1
 case $num1 in
  1)
   localeset
   selinuxset
   firewalldset
   chkset
   limitset
   yumset
   kernelset
   sshset
   restartset
   ntpdateset
   historyset
   ;;
  2)
   menu2
   case $num2 in
                  1)
                    localeset
                    ;;
                  2)
                    selinuxset
                    ;;
                  3)
                    firewalldset
                    ;;
                  4)
                    chkset
                    ;;
                  5)
                    limitset
                    ;;
                  6)
            yumset
                    ;;
                  7)
                    kernelset
                    ;;
                  8)
                    sshset
                    ;;
                  9)
                    restartset
                    ;;
                  10)
                    ntpdateset
                    ;;
    11)
      historyset
      ;;
    12)
      main
      ;;
    13)
      exit
      ;;
    *)
      echo &#39;Please select a number from [1-13].&#39;
      ;;
   esac
   ;;
  3)
   exit
   ;;
  *)
   echo &#39;Err:Please select a number from [1-3].&#39;
   sleep 3
   main
   ;;
 esac
}
main $*

Save it as init.sh, then grant execution permission and execute it.

chmod +x init.sh && ./init.sh

If it is troublesome to copy and paste back and forth like this, you can also execute it through my one-click command, which can also achieve the above effect:

bash -c "$(curl -L s.aaa.al/init.sh)"

Finally, if you have any functions you want to implement, It can also be modified and implemented based on the original script.

The above is the detailed content of CentOS 7 system optimization script. For more information, please follow other related articles on the PHP Chinese website!