sys_init

#!/bin/bash
yum install  -y wget && \
wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo && \
yum -y install vim wget bash-completion lrzsz nmap tree nc net-tools htop iotop iftop psmisc telnet && \
systemctl stop firewalld.service && systemctl disable firewalld.service
setenforce    && sed '7s#enforcing#disabled#g' /etc/selinux/config -i
#优化文件描述符
echo '*               -       nofile          65535 ' >>/etc/security/limits.conf
ulimit -n
#内核优化
cat >>/etc/sysctl.conf<<EOF
net.ipv4.tcp_fin_timeout =
net.ipv4.tcp_tw_reuse =
net.ipv4.tcp_tw_recycle =
net.ipv4.tcp_syncookies =
net.ipv4.tcp_keepalive_time =
net.ipv4.ip_local_port_range =
net.ipv4.tcp_max_syn_backlog =
net.ipv4.tcp_max_tw_buckets =
net.ipv4.route.gc_timeout =
net.ipv4.tcp_syn_retries =
net.ipv4.tcp_synack_retries =
net.core.somaxconn =
net.core.netdev_max_backlog =
net.ipv4.tcp_max_orphans =
EOF
sysctl -p
sed -i.bak 's@#UseDNS yes@UseDNS no@g;s@^GSSAPIAuthentication yes@GSSAPIAuthentication no@g'  /etc/ssh/sshd_config
systemctl restart sshd