centos7 系统优化脚本

脚本一：

 #!/usr/bin/env bash

 #设置环境变量
 export PATH=$PATH:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin

 function kernel () {
 echo "
 #CTCDN系统优化参数
 #关闭ipv6
 net.ipv6.conf.all.disable_ipv6 =
 net.ipv6.conf.default.disable_ipv6 =
 #决定检查过期多久邻居条目
 net.ipv4.neigh.default.gc_stale_time=
 #使用arp_announce / arp_ignore解决ARP映射问题
 net.ipv4.conf.default.arp_announce =
 net.ipv4.conf.all.arp_announce=
 net.ipv4.conf.lo.arp_announce=
 # 避免放大攻击
 net.ipv4.icmp_echo_ignore_broadcasts =
 # 开启恶意icmp错误消息保护
 net.ipv4.icmp_ignore_bogus_error_responses =
 #关闭路由转发
 net.ipv4.ip_forward =
 net.ipv4.conf.all.send_redirects =
 net.ipv4.conf.default.send_redirects =
 #开启反向路径过滤
 net.ipv4.conf.all.rp_filter =
 net.ipv4.conf.default.rp_filter =
 #处理无源路由的包
 net.ipv4.conf.all.accept_source_route =
 net.ipv4.conf.default.accept_source_route =
 #关闭sysrq功能
 kernel.sysrq =
 #core文件名中添加pid作为扩展名
 kernel.core_uses_pid =
 # 开启SYN洪水攻击保护
 net.ipv4.tcp_syncookies =
 #修改消息队列长度
 kernel.msgmnb =
 kernel.msgmax =
 #设置最大内存共享段大小bytes
 kernel.shmmax =
 kernel.shmall =
 #timewait的数量，默认180000
 net.ipv4.tcp_max_tw_buckets =
 net.ipv4.tcp_sack =
 net.ipv4.tcp_window_scaling =
 net.ipv4.tcp_rmem =
 net.ipv4.tcp_wmem =
 net.core.wmem_default =
 net.core.rmem_default =
 net.core.rmem_max =
 net.core.wmem_max =
 #每个网络接口接收数据包的速率比内核处理这些包的速率快时，允许送到队列的数据包的最大数目
 net.core.netdev_max_backlog =
 #限制仅仅是为了防止简单的DoS 攻击
 net.ipv4.tcp_max_orphans =
 #未收到客户端确认信息的连接请求的最大值
 net.ipv4.tcp_max_syn_backlog =
 net.ipv4.tcp_timestamps =
 #内核放弃建立连接之前发送SYNACK 包的数量
 net.ipv4.tcp_synack_retries =
 #内核放弃建立连接之前发送SYN 包的数量
 net.ipv4.tcp_syn_retries =
 #启用timewait 快速回收
 net.ipv4.tcp_tw_recycle =
 #开启重用。允许将TIME-WAIT sockets 重新用于新的TCP 连接
 net.ipv4.tcp_tw_reuse =
 net.ipv4.tcp_mem =
 net.ipv4.tcp_fin_timeout =
 #当keepalive 起用的时候，TCP 发送keepalive 消息的频度。缺省是2 小时
 net.ipv4.tcp_keepalive_time =
 net.ipv4.tcp_keepalive_probes =
 net.ipv4.tcp_keepalive_intvl =
 #允许系统打开的端口范围
 net.ipv4.ip_local_port_range =
 #修改防火墙表大小，默认65536
 net.netfilter.nf_conntrack_max=
 net.netfilter.nf_conntrack_tcp_timeout_established=
 # 确保无人能修改路由表
 net.ipv4.conf.all.accept_redirects =
 net.ipv4.conf.default.accept_redirects =
 net.ipv4.conf.all.secure_redirects =
 net.ipv4.conf.default.secure_redirects = " >> /etc/sysctl.conf

 read -r -p "是否开启路由转发? [y|n] " input
 case $input in
     y)
     sed -i "s#net.ipv4.ip_forward = 0#net.ipv4.ip_forward = 1#g" /etc/sysctl.conf
     sed -i "s#net.ipv4.conf.all.send_redirects = 0#net.ipv4.conf.all.send_redirects = 1#g"  /etc/sysctl.conf
     sed -i "s#net.ipv4.conf.default.send_redirects = 0#net.ipv4.conf.default.send_redirects = 1#g" /etc/sysctl.conf
     sysctl -p
     echo "优化完成，程序退出"
     ;;
     n)
     sysctl -p
     echo "优化完成，程序退出"
     exit
     ;;
 esac
 }

 # 是否优化内核
 function openkernel () {
     read -r -p "是否优化内核? [y/n] " input
     case $input in
         y)
         kernel
         ;;
         n)
         echo "优化完成，程序退出"
         exit
         ;;
     esac
 }

 # 修改文件数限制
 function openfile () {
     read -r -p "是否修改打开文件数的限制? [y/n] " input
     case $input in
         y)
         echo -e "* soft nofile 1024000\n* hard nofile 1024000\nhive   - nofile 1024000\nhive   - nproc  1024000" >> /etc/security/limits.conf
         openkernel
         ;;
         n)
         openkernel
         ;;
     esac
 }

 # 修改用户进程限制
 function userlimits () {
     read -r -p "是否加大普通用户限制? [y/n] " input
     case $input in
         y)
         sed -i 's#4096#65535#g'   /etc/security/limits.d/-nproc.conf
         openfile
         ;;
         n)
         openfile
         ;;
     esac
 }      

 # 修改主机名
 function hostname () {
     read -r -p "是否要修改主机名? [y/n]" input
     case $input in
         y)
         read -r -p "请输入主机名:" hostname
         hostnamectl set-hostname $hostname
         userlimits
         ;;
         n)
         userlimits
         ;;
     esac
 }

 # 基础优化函数
 function All () {
     yum -y install epel-release
     yum update
     yum -y install net-tools tree lrzsz unzip telnet vim gcc cmake wget git ntpdate bash-completion
     sed -i "/^SELINUX/s#enforcing#disabled#g" /etc/selinux/config
     cp /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
     echo -e "*/1 * * * * ntpdate ntp1.aliyun.com" > /var/spool/cron/root
     hostname
 }

 echo "--------------------------------------------------------------------"
 echo "本脚本可以根据需求选择要优化的选项-只是针对刚刚安装好的系统做优化,并且保证正常上网"
 echo "--------------------------------------------------------------------"
 echo "请选择你要使用的选项:"
 echo "(0) 基本优化"
 echo "(9) Exit"
 echo "--------------------------------------------------------------------"
 read -p "请输入选项编号>>>>:" input

 case $input in
     )
     echo "-----------执行基本优化---------------"
     sleep
     All;;
     )
     echo "-----------退出脚本---------------"
     exit;;
 esac

脚本二：

#!/bin/bash

#Cenetos6/7初始化脚本
# get os version
RELEASEVER=$(rpm -q --qf "%{VERSION}" $(rpm -q --whatprovides redhat-release))

# configure yum source
cd /etc/yum.repos.d/
mkdir /etc/yum.repos.d/bak
mv /etc/yum.repos.d/*.repo /etc/yum.repos.d/bak
if [ $RELEASEVER == 6 ];then
    curl http://mirrors.163.com/.help/CentOS6-Base-163.repo > qf.repo
fi
if [ $RELEASEVER == 7 ];then
    curl http://mirrors.163.com/.help/CentOS7-Base-163.repo > qf.repo
fi
yum clean all
yum check-update

# install base rpm package
yum -y install epel-release
yum -y install nc vim iftop iotop dstat tcpdump
yum -y install ipmitool bind-libs bind-utils
yum -y install libselinux-python ntpdate

# update rpm package include kernel
yum -y update
rm -rf /etc/yum.repos.d/CentOS*

# update ulimit configure
if [ $RELEASEVER == 6 ];then
    test -f /etc/security/limits.d/90-nproc.conf && rm -rf /etc/security/limits.d/90-nproc.conf && touch /etc/security/limits.d/90-nproc.conf
fi
if [ $RELEASEVER == 7 ];then
    test -f /etc/security/limits.d/20-nproc.conf && rm -rf /etc/security/limits.d/20-nproc.conf && touch /etc/security/limits.d/20-nproc.conf
fi

> /etc/security/limits.conf
cat >> /etc/security/limits.conf <<EOF
* soft nproc 65535
* hard nproc 65535
* soft nofile 65535
* hard nofile 65535
EOF

# set timezone
test -f /etc/localtime && rm -rf /etc/localtime
ln -s /usr/share/zoneinfo/Asia/Shanghai /etc/localtime

# set LANG
if [ $RELEASEVER == 6 ];then
sed -i 's@LANG=.*$@LANG="en_US.UTF-8"@g' /etc/sysconfig/i18n
fi
if [ $RELEASEVER == 7 ];then
sed -i 's@LANG=.*$@LANG="en_US.UTF-8"@g' /etc/locale.conf
fi

# update time
if [ $RELEASEVER == 6 ];then
    /usr/sbin/ntpdate -b pool.ntp.org
    grep -q ntpdate /var/spool/cron/root
    if [ $? -ne 0 ]; then
        echo '* * * * * /usr/sbin/ntpdate pool.ntp.org > /dev/null 2>&1' > /var/spool/cron/root;chmod 600 /var/spool/cron/root
    fi
    /etc/init.d/crond restart
fi

if [ $RELEASEVER == 7 ];then
    yum -y install chrony
    > /etc/chrony.conf
cat > /etc/chrony.conf << EOF
server pool.ntp.org iburst
stratumweight 0
driftfile /var/lib/chrony/drift
rtcsync
makestep 10 3
bindcmdaddress 127.0.0.1
bindcmdaddress ::1
keyfile /etc/chrony.keys
commandkey 1
generatecommandkey
noclientlog
logchange 0.5
logdir /var/log/chrony
EOF

systemctl restart chronyd
systemctl enable chronyd
fi

# clean iptables default rules
if [ $RELEASEVER == 6 ];then
    /sbin/iptables -F
    service iptables save
    chkconfig iptables off
fi
if [ $RELEASEVER == 7 ];then
    systemctl disable firewalld
fi

# disable unused service
chkconfig auditd off

# disable ipv6
cd /etc/modprobe.d/ && touch ipv6.conf
> /etc/modprobe.d/ipv6.conf
cat >> /etc/modprobe.d/ipv6.conf << EOF
alias net-pf-10 off
alias ipv6 off
EOF

# disable iptable nat moudule
cd /etc/modprobe.d/ && touch connectiontracking.conf
> /etc/modprobe.d/connectiontracking.conf
cat >> /etc/modprobe.d/connectiontracking.conf <<EOF
install nf_nat /bin/true
install xt_state  /bin/true
install iptable_nat /bin/true
install nf_conntrack /bin/true
install nf_defrag_ipv4   /bin/true
install nf_conntrack_ipv4 /bin/true
install nf_conntrack_ipv6  /bin/true
EOF

# disable SELINUX
setenforce 0
sed -i 's/^SELINUX=.*$/SELINUX=disabled/' /etc/selinux/config

# update record command
sed -i 's/^HISTSIZE=.*$/HISTSIZE=100000/' /etc/profile
grep -q 'HISTTIMEFORMAT' /etc/profile
if [[ $? -eq 0 ]]; then
sed -i 's/^HISTTIMEFORMAT=.*$/HISTTIMEFORMAT="%F %T "/' /etc/profile
else
echo 'HISTTIMEFORMAT="%F %T "' >> /etc/profile
fi

# install dsnmasq and update configure //本地dns查询缓存
yum -y install dnsmasq
> /etc/dnsmasq.conf
cat >> /etc/dnsmasq.conf<< EOF
listen-address=127.0.0.1
no-dhcp-interface=lo
log-queries
log-facility=/var/log/dnsmasq.log
all-servers
no-negcache
cache-size=1024
dns-forward-max=512
EOF

if [ $RELEASEVER == 6 ];then
    /etc/init.d/dnsmasq restart
fi

if [ $RELEASEVER == 7 ];then
    systemctl restart dnsmasq
systemctl enable dnsmasq
fi

# update /etc/resolv.conf
> /etc/resolv.conf
cat >> /etc/resolv.conf<< EOF
options timeout:1
nameserver 127.0.0.1
nameserver 114.114.114.114
EOF

# update /etc/sysctl.conf
cat >> /etc/sysctl.conf<< EOF
net.ipv4.tcp_syncookies = 1
kernel.core_uses_pid=1
kernel.core_pattern=/tmp/core-%e-%p
fs.suid_dumpable=2
net.ipv4.tcp_tw_reuse=1
net.ipv4.tcp_tw_recycle=0
net.ipv4.tcp_timestamps=1
EOF
sysctl -p

#注：按标签查看rpm包信息
## rpm -q vsftpd
#vsftpd-3.0.2-21.el7.x86_64
##
## rpm -q --qf "%{NAME}" vsftpd
#vsftpd#
## rpm -q --qf "%{NAME}\n" vsftpd
#vsftpd
## rpm -q --qf "%{VERSION}\n" vsftpd
#3.0.2
## rpm -q --qf "%{RELEASE}\n" vsftpd
#21.el7
## rpm -q --qf "%{ARCH}\n" vsftpd
#x86_64