系统优化脚本
#!/bin/bash #author junxi by #this script is only for CentOS 7.x #check the OS platform=`uname -i` if [ $platform != "x86_64" ];then echo "this script is only for 64bit Operating System !" exit 1 fi echo "the platform is ok" cat << EOF +---------------------------------------+ | your system is CentOS 7 x86_64 | | start optimizing....... | +--------------------------------------- EOF #添加公网DNS地址 cat >> /etc/resolv.conf << EOF nameserver 223.6.6.6 EOF #Yum源更换为国内阿里源 yum install wget -y mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo #添加阿里的epel源 #add the epel wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo #yum重新建立缓存 yum clean all yum makecache #同步时间 yum -y install ntp /usr/sbin/ntpdate cn.pool.ntp.org echo "* 4 * * * /usr/sbin/ntpdate cn.pool.ntp.org > /dev/null 2>&1" >> /var/spool/cron/root systemctl restart crond.service #设置主机名 hostnamectl set-hostname qiuyuetao #设置字符集 #设置最大打开文件描述符数 echo "ulimit -SHn 102400" >> /etc/rc.local cat >> /etc/security/limits.conf << EOF * soft nofile 655350 * hard nofile 655350 EOF #禁用selinux sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config setenforce 0 #关闭防火墙 systemctl disable firewalld.service systemctl stop firewalld.service #set ssh sed -i 's/^GSSAPIAuthentication yes$/GSSAPIAuthentication no/' /etc/ssh/sshd_config sed -i 's/#UsednS yes/UsednS no/' /etc/ssh/sshd_config systemctl restart sshd.service #内核参数优化 cat >> /etc/sysctl.conf << EOF #CTCDN系统优化参数 #关闭ipv6 net.ipv6.conf.all.disable_ipv6 = 1 net.ipv6.conf.default.disable_ipv6 = 1 #决定检查过期多久邻居条目 net.ipv4.neigh.default.gc_stale_time=120 #使用arp_announce / arp_ignore解决ARP映射问题 net.ipv4.conf.default.arp_announce = 2 net.ipv4.conf.all.arp_announce=2 net.ipv4.conf.lo.arp_announce=2 # 避免放大攻击 net.ipv4.icmp_echo_ignore_broadcasts = 1 # 开启恶意icmp错误消息保护 net.ipv4.icmp_ignore_bogus_error_responses = 1 #关闭路由转发 net.ipv4.ip_forward = 0 net.ipv4.conf.all.send_redirects = 0 net.ipv4.conf.default.send_redirects = 0 #开启反向路径过滤 net.ipv4.conf.all.rp_filter = 1 net.ipv4.conf.default.rp_filter = 1 #处理无源路由的包 net.ipv4.conf.all.accept_source_route = 0 net.ipv4.conf.default.accept_source_route = 0 #关闭sysrq功能 kernel.sysrq = 0 #core文件名中添加pid作为扩展名 kernel.core_uses_pid = 1 # 开启SYN洪水攻击保护 net.ipv4.tcp_syncookies = 1 #修改消息队列长度 kernel.msgmnb = 65536 kernel.msgmax = 65536 #设置最大内存共享段大小bytes kernel.shmmax = 68719476736 kernel.shmall = 4294967296 #timewait的数量，默认180000 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 #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 = 262144 #限制仅仅是为了防止简单的DoS 攻击 net.ipv4.tcp_max_orphans = 3276800 #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 = 262144 net.ipv4.tcp_timestamps = 0 #内核放弃建立连接之前发送SYNACK 包的数量 net.ipv4.tcp_synack_retries = 1 #内核放弃建立连接之前发送SYN 包的数量 net.ipv4.tcp_syn_retries = 1 #启用timewait 快速回收 net.ipv4.tcp_tw_recycle = 1 #开启重用。允许将TIME-WAIT sockets 重新用于新的TCP 连接 net.ipv4.tcp_tw_reuse = 1 net.ipv4.tcp_mem = 94500000 915000000 927000000 net.ipv4.tcp_fin_timeout = 1 #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 = 1800 net.ipv4.tcp_keepalive_probes = 3 net.ipv4.tcp_keepalive_intvl = 15 #允许系统打开的端口范围 net.ipv4.ip_local_port_range = 1024 65000 #修改防火墙表大小，默认65536 net.netfilter.nf_conntrack_max=655350 net.netfilter.nf_conntrack_tcp_timeout_established=1200 # 确保无人能修改路由表 net.ipv4.conf.all.accept_redirects = 0 net.ipv4.conf.default.accept_redirects = 0 net.ipv4.conf.all.secure_redirects = 0 net.ipv4.conf.default.secure_redirects = 0 EOF /sbin/sysctl -p #vim定义退格键可删除最后一个字符类型 echo 'alias vi=vim' >> /etc/profile echo 'stty erase ^H' >> /etc/profile cat >> /root/.vimrc << EOF set tabstop=4 set shiftwidth=4 set expandtab Syntax on "set number EOF #update soft yum -y update cat << EOF +-------------------------------------------------+ | 优 化 已 完 成 | | 5s 后 重启 这台服务器 ! | +-------------------------------------------------+ EOF sleep 5 reboot ##重启加载内核修改
内核升级脚本
rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-2.el7.elrepo.noarch.rpm yum --enablerepo=elrepo-kernel install kernel-ml -y&& sed -i s/saved/0/g /etc/default/grub&& grub2-mkconfig -o /boot/grub2/grub.cfg && reboot #不重启不生效！
