Linux集群和自动化维1.4.3　CentOS 6.4 x86_64系统最小化优化脚本

1.4.3　CentOS 6.4 x86_64系统最小化优化脚本

 CentOS 6.4 x86_64系统最小化优化脚本，脚本内容如下所示（请注意下面的代码中有中文注释内容，如果是放在线上运行时则要注意）：

#!/bin/bash

#系统基础升级

wget http://mirrors.163.com/.help/CentOS6-Base-163.repo

cd /etc/yum.repos.d/

mv CentOS-Base.repo CentOS-Base.repo.bak

mv CentOS6-Base-163.repo CentOS-Base.repo

yum clean all #清除yum缓存

yum makecache #重建缓存

yum update  #升级Linux系统

#添加epel外部yum扩展源

cd /usr/local/src

wget http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm

rpm -ivh epel-release-6-8.noarch.rpm

#安装gcc基础库文件及sysstat工具

yum -y install gcc gcc-c++ vim-enhanced unzip unrar sysstat

#配置ntpdate自动对时

yum -y install ntp

echo "01 01 * * * /usr/sbin/ntpdate ntp.api.bz    >> /dev/null 2>&1" >> /etc/crontab

ntpdate ntp.api.bz

service crond restart

#配置文件的ulimit值

ulimit -SHn 65534

echo "ulimit -SHn 65534" >> /etc/rc.local

cat >> /etc/security/limits.conf << EOF

*                     soft     nofile             65534

*                     hard     nofile             65534

EOF

#基础系统内核优化

cat >> /etc/sysctl.conf << EOF

net.ipv4.tcp_syncookies = 1

net.ipv4.tcp_syn_retries = 1

net.ipv4.tcp_tw_recycle = 1

net.ipv4.tcp_tw_reuse = 1

net.ipv4.tcp_fin_timeout = 1

net.ipv4.tcp_keepalive_time = 1200

net.ipv4.ip_local_port_range = 10000 65535

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 = 1

net.core.somaxconn = 16384

net.core.netdev_max_backlog = 16384

net.ipv4.tcp_max_orphans = 16384

EOF

/sbin/sysctl -p

#禁用control-alt-delete组合键以防止误操作

sed -i 's@ca::ctrlaltdel:/sbin/shutdown -t3 -r now@#ca::ctrlaltdel:/sbin/shutdown     -t3 -r now@' /etc/inittab

#关闭SELinux

sed -i 's@SELINUX=enforcing@SELINUX=disabled@' /etc/selinux/config

#关闭iptables

service iptables stop

chkconfig iptables off

#ssh服务配置优化,请保持机器中至少存在一个具有sudo权限的用户，下面的配置会禁止root远程登录

sed -i 's@#PermitRootLogin yes@PermitRootLogin no@' /etc/ssh/sshd_config

#禁止空密码登录

sed -i 's@#PermitEmptyPasswords no@PermitEmptyPasswords no@' /etc/ssh/sshd_config

#禁止SSH反向解析

sed -i 's@#UseDNS yes@UseDNS no@' /etc/ssh/sshd_config /etc/ssh/sshd_config

service sshd restart

#禁用IPv6地址

echo "install ipv6 /bin/true" > /etc/modprobe.d/disable-ipv6.conf

#每当系统需要加载IPv6模块时，强制执行/bin/true来代替实际加载的模块

echo "IPV6INIT=no" >> /etc/sysconfig/network-scripts/ifcfg-eth0

#禁用基于IPv6网络，使之不会被触发启动

chkconfig ip6tables off

#vim基础语法优化

cat >> /root/.vimrc << EOF

set number

set ruler

set nohlsearch

set shiftwidth=2

set tabstop=4

set expandtab

set cindent

set autoindent

set mouse=v

syntax on

EOF

#精简开机自启动服务，安装最小化服务的机器初始可以只保留crond|network|rsyslog|sshd这4个服务

for i in `chkconfig --list|grep 3:on|awk '{print $1}'`;do chkconfig --level 3 $i off;done

for CURSRV  in crond rsyslog sshd network;do chkconfig --level 3 $CURSRV on;done

#重启服务器

reboot