分享一个CentOS 6 初始化脚本

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：

1. #!/bin/bash
   
2. #author suzezhi
   
3. #this script is only for CentOS 6
   
4. #check the OS
   
5. platform=`uname -i`
   
6. if [ $platform != "x86_64" ];then
   
7. echo "this script is only for 64bit Operating System !"
   
8. exit 1
   
9. fi
   
10. echo "the platform is ok"
    
11. version=`lsb_release -r |awk '{print substr($2,1,1)}'`
    
12. if [ $version != 6 ];then
    
13. echo "this script is only for CentOS 6 !"
    
14. exit 1
    
15. fi
    
16. 
    
17. cat << EOF
    
18. +---------------------------------------+
    
19. |   your system is CentOS 6 x86_64      |
    
20. |        start optimizing.......                   |
    
21. +---------------------------------------
    
22. EOF
    
23. 
    
24. #make the 163.com as the default yum repo
    
25. mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
    
26. wget -O /etc/yum.repos.d/CentOS-Base.repo
    
27. 
    
28. #add the third-party repo
    
29. #add the epel
    
30. rpm -Uvh
    
31. rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-6
    
32. #add the rpmforge
    
33. rpm -Uvh
    
34. rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-rpmforge-dag
    
35. 
    
36. #update the system and set the ntp
    
37. yum clean all
    
38. yum install kernel-devel kernel-headers && echo exclude=kernel* >> /etc/yum.conf
    
39. yum -y update glibc\*
    
40. yum -y update yum\* rpm\* python\*
    
41. yum -y update
    
42. yum -y install ntp
    
43. echo "* 4 * * * /usr/sbin/ntpdate 210.72.145.44 > /dev/null 2>&1" >> /var/spool/cron/root
    
44. service crond restart
    
45. 
    
46. #set the file limit
    
47. echo "ulimit -SHn 102400" >> /etc/rc.local
    
48. cat >> /etc/security/limits.conf << EOF
    
49. *           soft   nofile       65535
    
50. *           hard   nofile       65535
    
51. EOF
    
52. 
    
53. #set the control-alt-delete to guard against the misuse
    
54. sed -i 's#exec /sbin/shutdown -r now#\#exec /sbin/shutdown -r now#' /etc/init/control-alt-delete.conf
    
55. 
    
56. #disable selinux
    
57. sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config
    
58. 
    
59. #set ssh
    
60. sed -i 's/^GSSAPIAuthentication yes$/GSSAPIAuthentication no/' /etc/ssh/sshd_config
    
61. sed -i 's/#UseDNS yes/UseDNS no/' /etc/ssh/sshd_config
    
62. service sshd restart
    
63. 
    
64. #tune kernel parametres
    
65. cat >> /etc/sysctl.conf << EOF
    
66. net.ipv4.tcp_fin_timeout = 1
    
67. net.ipv4.tcp_keepalive_time = 1200
    
68. net.ipv4.tcp_mem = 94500000 915000000 927000000
    
69. net.ipv4.tcp_tw_reuse = 1
    
70. net.ipv4.tcp_timestamps = 0
    
71. net.ipv4.tcp_synack_retries = 1
    
72. net.ipv4.tcp_syn_retries = 1
    
73. net.ipv4.tcp_tw_recycle = 1
    
74. net.core.rmem_max = 16777216
    
75. net.core.wmem_max = 16777216
    
76. net.core.netdev_max_backlog = 262144
    
77. net.core.somaxconn = 262144
    
78. net.ipv4.tcp_max_orphans = 3276800
    
79. net.ipv4.tcp_max_syn_backlog = 262144
    
80. net.core.wmem_default = 8388608
    
81. net.core.rmem_default = 8388608
    
82. EOF
    
83. /sbin/sysctl -p
    
84. 
    
85. #define the backspace button can erase the last character typed
    
86. echo 'stty erase ^H' >> /etc/profile
    
87. 
    
88. echo "syntax on" >> /root/.vimrc
    
89. 
    
90. #stop some crontab
    
91. mkdir /etc/cron.daily.bak
    
92. mv /etc/cron.daily/makewhatis.cron /etc/cron.daily.bak
    
93. mv /etc/cron.daily/mlocate.cron /etc/cron.daily.bak
    
94. 
    
95. chkconfig bluetooth off
    
96. chkconfig cups off
    
97. chkconfig ip6tables off
    
98. 
    
99. 
    
100. #disable the ipv6
     
101. cat > /etc/modprobe.d/ipv6.conf << EOFI
     
102. alias net-pf-10 off
     
103. options ipv6 disable=1
     
104. EOFI
     
105. 
     
106. echo "NETWORKING_IPV6=off" >> /etc/sysconfig/network
     
107. cat << EOF
     
108. +-------------------------------------------------+
     
109. |               optimizer is done                               |
     
110. |   it's recommond to restart this server !             |
     
111. +-------------------------------------------------+
     
112. EOF

复制代码

对脚本的内容做一下说明（给不太熟悉的哥们扫扫盲，高手直接绕开就行）：
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