yum -y install epel-release

yum -y install wget nmap lsof iotop lrzsz ntpdate tree

rm -rf /etc/localtime
cp /usr/share/zoneinfo/Asia/Shanghai /etc/localtime

ntpdate time1.aliyun.com
crontab -e
*/3 * * * * /usr/sbin/ntpdate time1.aliyun.com >/dev/null 2>&1

systemctl disable firewalld.service
systemctl stop firewalld.service
sed -i 's/^SELINUX=.*/SELINUX=disabled/g' /etc/selinux/config && setenforce 0

swapoff -a
sed -i 's/^.*swap/#&/g'  /etc/fstab

vim /etc/sysctl.conf
net.ipv4.tcp_keepalive_time = 1200
net.ipv4.ip_local_port_range = 1024 65000
net.ipv4.tcp_max_syn_backlog = 8192
net.ipv4.tcp_max_tw_buckets = 5000
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_fin_timeout = 30
vm.max_map_count = 262144
fs.file-max = 655350
net.core.somaxconn=20480
net.ipv4.ip_forward = 1
sysctl -p

vim /etc/security/limits.conf
*    soft    nofile   655350
*    hard    nofile   655350
*    soft    nproc    655350
*    hard    nproc    655350