1.服务器时间要同步

2.禁用selinux

3.关闭防火墙

4.历史命令显示操作时间

5.ssh超时时间

6.禁止root远程登录

7.禁止定时任务向发送邮件

8.设置最大打开文件数

9.系统内核优化

10.安装系统性能分析工具及常用工具

为了方便这里用脚本统一实现：

#/bin/bash
# 设置时区并同步时间
ln -s /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
if ! crontab -l |grep ntpdate &>/dev/null ; then
(echo "* 1 * * *  ntp.aliyun.com >/dev/null 2>&1";crontab -l)
|crontab
fi
# 禁用selinux
sed -i '/SELINUX/{s/permissive/disabled/}' /etc/selinux/config
# 关闭防火墙
if egrep "7.[0-9]" /etc/redhat-release &>/dev/null; then
systemctl stop firewalld
systemctl disable firewalld
elif egrep "6.[0-9]" /etc/redhat-release &>/dev/null; then
service iptables stop
chkconfig iptables off
fi
# 历史命令显示操作时间
if ! grep HISTTIMEFORMAT /etc/bashrc; then
echo 'export HISTTIMEFORMAT="%F %T `whoami` "' >> /etc/bashrc
fi
# SSH超时时间
if ! grep "TMOUT=600" /etc/profile &>/dev/null; then
echo "export TMOUT=600" >> /etc/profile
fi
# 禁止root远程登录
sed -i 's/#PermitRootLogin yes/PermitRootLogin no/' /etc/ssh/sshd_config
# 禁止定时任务向发送邮件
sed -i 's/^MAILTO=root/MAILTO=""/' /etc/crontab
# 设置最大打开文件数
if ! grep "* soft nofile 65535" /etc/security/limits.conf &>/dev/null; then
cat >> /etc/security/limits.conf << EOF
* soft nofile 65535
* hard nofile 65535
EOF
fi
# 系统内核优化
cat >> /etc/sysctl.conf << EOF
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_max_tw_buckets = 20480
net.ipv4.tcp_max_syn_backlog = 20480
net.core.netdev_max_backlog = 262144
net.ipv4.tcp_fin_timeout = 20
EOF
# 安装系统性能分析工具及其他
yum install -y gcc make autoconf vim sysstat net-tools iostat if iftop