SHELL script for system initialization

This script is used to configure new Linux instances, such as disabling iptable, SElinux, and ipv6, optimizing the system kernel, and stopping unnecessary system services. This script is especially suitable for a large number of newly installed Centsos Series servers. The script code is as follows (this script is passed under Centos5.5 _ x64 ):
#! /Bin/bash
# Created by kerryhu
# MAIL: king_819@163.com
# BLOG: http://kerry.blog.51cto.com
Cat <EOF
+ -------------------------------------------------------------- +
| === Welcome to Centos System init ==|
+ -------------------------------------------------------------- +
+ -------------------------- By kerry ---------------------------- +
EOF

# Set ntp
Yum-y install ntp
Echo "* 3 ***/usr/sbin/ntpdate 210.72.145.44>/dev/null 2> & 1">/etc/crontab
Service crond restart
# Set ulimit
Echo "ulimit-SHn 102400">/etc/rc. local
# Set locale
# True>/etc/sysconfig/i18n
# Cat>/etc/sysconfig/i18n <EOF
# LANG = "zh_CN.GB18030"
# SUPPORTED = "zh_CN.GB18030: zh_CN: zh: en_US.UTF-8: en_US: en"
# SYSFONT = "latarcyrheb-sun16"
# EOF
# Set sysctl
True>/etc/sysctl. conf
Cat>/etc/sysctl. conf <EOF
Net. ipv4.ip _ forward = 0
Net. ipv4.conf. default. rp_filter = 1
Net. ipv4.conf. default. accept_source_route = 0
Kernel. sysrq = 0
Kernel. core_uses_pid = 1
Net. ipv4.tcp _ syncookies = 1
Kernel. msgmnb = 65536
Kernel. msgmax = 65536
Kernel. shmmax = 68719476736
Kernel. shmall = 4294967296
Net. ipv4.tcp _ max_tw_buckets = 6000
Net. ipv4.tcp _ sack = 1
Net. ipv4.tcp _ window_scaling = 1
Net. ipv4.tcp _ rmem = 4096 87380 4194304
Net. ipv4.tcp _ wmem = 4096 16384 4194304
Net. core. wmem_default = 8388608
Net. core. rmem_default = 8388608
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. ipv4.tcp _ timestamps = 0
Net. ipv4.tcp _ synack_retries = 1
Net. ipv4.tcp _ syn_retries = 1
Net. ipv4.tcp _ tw_recycle = 1
Net. ipv4.tcp _ tw_reuse = 1
Net. ipv4.tcp _ mem = 94500000 915000000 927000000
Net. ipv4.tcp _ fin_timeout = 1
Net. ipv4.tcp _ keepalive_time = 1200
Net. ipv4.ip _ local_port_range = 1024 65535
EOF
/Sbin/sysctl-p
Echo "sysctl set OK !! "
# Close ctrl + alt + del
Sed-I "s/ca: ctrlaltdel: \/sbin \/shutdown-t3-r now/# ca: ctrlaltdel: \/sbin \/shutdown-t3-r now/"/etc/inittab
# Set purview
Chmod 600/etc/passwd
Chmod 600/etc/shadow
Chmod 600/etc/group
Chmod 600/etc/gshadow
# Disable ipv6
Cat <EOF
+ -------------------------------------------------------------- +
| === Welcome to Disable IPV6 ==|
+ -------------------------------------------------------------- +
EOF
Echo "alias net-pf-10 off">/etc/modprobe. conf
Echo "alias ipv6 off">/etc/modprobe. conf
/Sbin/chkconfig -- level 35 ip6tables off
Echo "ipv6 is disabled! "
# Disable selinux
Sed-I '/SELINUX/s/enforcing/disabled/'/etc/selinux/config
Echo "selinux is disabled, you must reboot! "
# Vim
Sed-I "8 s/^/alias vi = 'vim '/"/root/. bashrc
Echo 'syntax on'>/root/. vimrc
# Zh_cn
Sed-I-e's/^ LANG =. */LANG = "en"/'/etc/sysconfig/i18n
# Init_ssh
Ssh_cf = "/etc/ssh/sshd_config"
Sed-I-e '74 s/^/#/'-I-e '76 s/^/#/' $ ssh_cf
# Sed-I "s/# Port 22/Port 65535/" $ ssh_cf
Sed-I "s/# UseDNS yes/UseDNS no/" $ ssh_cf
# Client
Sed-I-e '44 s/^/#/'-I-e' 48 s/^/#/'$ ssh_cf
Service sshd restart
Echo "ssh is init is OK .............."
# Chkser
# Tunoff services
#--------------------------------------------------------------------------------
Cat <EOF
+ -------------------------------------------------------------- +
| === Welcome to Tunoff services ===|
+ -------------------------------------------------------------- +
EOF
#---------------------------------------------------------------------------------
For I in 'ls/etc/rc3.d/S *'
Do
CURSRV = 'echo $ I | cut-c 15 -'
Echo $ CURSRV
Case $ CURSRV in
Crond | irqbalance | microcode_ctl | network | random | sshd | syslog | local)
Echo "Base services, Skip! "
;;
*)
Echo "change $ CURSRV to off"
Chkconfig -- level 235 $ CURSRV off
Service $ CURSRV stop
;;
Esac
Done
Echo "service is init is OK .............."

This script is excerpted from the book "Building a high-availability Linux Server" (Machinery Industry Press), reprinting the trouble to indicate the source, thank you.

This article from the "fuqin liquor" blog, please be sure to keep this source http://andrewyu.blog.51cto.com/1604432/724103