CentOS 6 系统优化 Shell 脚本

CentOS 已经发布了6.2版了，现在已经可以用在生产环境了，新版本的内核也能更好的利用硬件。写了一个脚本，用来初始化系统环境，现在分享出来，你可以根据自己的需要，对脚本进行相应的修改。

脚本的内容如下：

 


  
#!/bin/bash

  
#author suzezhi

  
#this script is only for CentOS 6

  
#check the OS

  
 
  
platform=`uname -i`

  
if [ $platform != "x86_64" ];then

  
echo "this script is only for 64bit Operating System !"

  
exit 1

  
fi

  
echo "the platform is ok"

  
version=`lsb_release -r |awk '{print substr($2,1,1)}'`

  
if [ $version != 6 ];then

  
echo "this script is only for CentOS 6 !"

  
exit 1

  
fi

  
cat << EOF

  
+---------------------------------------+

  
| your system is CentOS 6 x86_64 |

  
| start optimizing....... |

  
+---------------------------------------

  
EOF

  
 
  
#make the 163.com as the default yum repo

  
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup

  
wget http://mirrors.163.com/.help/CentOS6-Base-163.repo -O /etc/yum.repos.d/CentOS-Base.repo

  
 
  
#add the third-party repo

  
#add the epel

  
rpm -Uvh http://download.Fedora.RedHat.com/pub/epel/6/x86_64/epel-release-6-5.noarch.rpm

  
rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-6

  
 
  
#add the rpmforge

  
rpm -Uvh http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.x86_64.rpm

  
rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-rpmforge-dag

  
 
  
#update the system and set the ntp

  
yum clean all

  
yum -y update glibc\*

  
yum -y update yum\* rpm\* python\*

  
yum -y update

  
yum -y install ntp

  
echo "* 4 * * * /usr/sbin/ntpdate 210.72.145.44 > /dev/null 2>&1" >> /var/spool/cron/root

  
service crond restart

  
 
  
#set the file limit

  
echo "ulimit -SHn 102400" >> /etc/rc.local

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

  
* soft nofile 65535

  
* hard nofile 65535

  
EOF

  
 
  
#set the control-alt-delete to guard against the miSUSE

  
sed -i 's#exec /sbin/shutdown -r now#\#exec /sbin/shutdown -r now#' /etc/init/control-alt-delete.conf

  
 
  
#disable selinux

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

  
 
  
#set ssh

  
sed -i 's/^GSSAPIAuthentication yes$/GSSAPIAuthentication no/' /etc/ssh/sshd_config

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

  
service sshd restart

  
 
  
#tune kernel parametres

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

  
net.ipv4.tcp_fin_timeout = 1

  
net.ipv4.tcp_keepalive_time = 1200

  
net.ipv4.tcp_mem = 94500000 915000000 927000000

  
net.ipv4.tcp_tw_reuse = 1

  
net.ipv4.tcp_timestamps = 0

  
net.ipv4.tcp_synack_retries = 1

  
net.ipv4.tcp_syn_retries = 1

  
net.ipv4.tcp_tw_recycle = 1

  
net.core.rmem_max = 16777216

  
net.core.wmem_max = 16777216

  
net.core.netdev_max_backlog = 262144

  
net.core.somaxconn = 262144

  
net.ipv4.tcp_max_orphans = 3276800

  
net.ipv4.tcp_max_syn_backlog = 262144

  
net.core.wmem_default = 8388608

  
net.core.rmem_default = 8388608

  
EOF

  
/sbin/sysctl -p

  
 
  
#define the backspace button can erase the last character typed

  
echo 'stty erase ^H' >> /etc/profile

  
echo "syntax on" >> /root/.vimrc

  
 
  
#stop some crontab

  
mkdir /etc/cron.daily.bak

  
mv /etc/cron.daily/makewhatis.cron /etc/cron.daily.bak

  
mv /etc/cron.daily/mlocate.cron /etc/cron.daily.bak

  
chkconfig bluetooth off

  
chkconfig cups off

  
chkconfig ip6tables off

  
#disable the ipv6

  
cat > /etc/modprobe.d/ipv6.conf << EOFI

  
alias net-pf-10 off

  
options ipv6 disable=1

  
EOFI

  
echo "NETWORKING_IPV6=off" >> /etc/sysconfig/network

  
cat << EOF

  
+-------------------------------------------------+

  
| optimizer is done |

  
| it's recommond to restart this server ! |

  
+-------------------------------------------------+

  
EOF

 

对脚本的内容做一下说明：

1. 先对系统进行判断，如果是Cent OS 64位，就继续运行。
2. 先将系统的安装源设置为网易的（网易的安装源算是国内比较稳定的）
3. 安装epel的源和rpmforge的源，利用第三方的源来让yum安装起来更方便
4. 更新软件
5. 设置为每天凌晨四点进行时间同步（跟国家授时中心的服务器进行时间同步）
6. 将系统同时打开的文件个数增大
7. 将ctrl ALT delete键进行屏蔽，防止误操作的时候服务器重启
8. 关闭SELinux
9. 禁用GSSAPI来认证，也禁用DNS反向解析，加快SSH登陆速度
10. 优化一些内核参数
11. 调整删除字符的按键为backspace（某些系统默认是delete）
12. 打开vim的语法高亮
13. 取消生成whatis数据库和locate数据库
14. 关闭没用的服务
15. 关闭IPv6

http://www.linuxde.net/2011/12/5756.html