centos7.9系统性能优化脚本

#!/bin/bash

source /etc/rc.d/init.d/functions

# 一级菜单
menu1(){
    clear
    cat << EOF
-----------------------------------------------
|**********欢迎使用centos7.9优化脚本***********|
-----------------------------------------------
1. 一键优化
2. 自定义优化
3. 退出
EOF
    read -p "请选择[1-3]: " num1

}

# 二级菜单
menu2(){
    clear
    cat << EOF
-----------------------------------
|**********请选择【1-11】**********|
-----------------------------------
1. 关闭selinux
2. 关闭firewalld
3. 修改文件句柄数ulimit
4. 修改yum源使用阿里云yum源
5. 优化系统内核
6. 加快ssh登录速度
7. 设置时间同步
8. 关闭NetworkManager
9. 安装常用软件包
10. 返回上一层
11. 退出
EOF

    read -p "请选择需要优化项目【1-11】：" num2

}

# 1.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/enforcing/disabled/' /etc/selinux/config
        setenforce 0
        echo "# grep SELINUX=disabled /etc/sysconfig/selinux"
        grep SELINUX=disabled /etc/sysconfig/selinux
        echo "# getenforce"
        getenforce
    else
        echo "SELINUX已处于关闭状态"
        echo "# grep SELINUX=disabled /etc/sysconfig/selinux"
        grep SELINUX=disabled /etc/sysconfig/selinux
        echo "# getenforce"
        getenforce        
    fi
    action "已禁用SELINUX" /bin/true
    echo "==================================================="
    sleep 2
}

# 2.关闭firewalld
firewalldset(){
    echo "====================禁用firewalld=================="
    systemctl stop firewalld
    echo "#firewall-cmd  --state"
    firewall-cmd  --state
    systemctl disable firewalld &> /dev/null
    echo "#systemctl status firewalld"
    systemctl status firewalld
    action "已禁用firewalld" /bin/true
    echo "=============================