防火墙: systemctl stop firewalld systemctl disable firewalld systemctl list-unit-files | grep firewalld ftp服务 启动ftp和开机自启动命令 /bin/systemctl start vsftpd.service systemctl enable vsftpd.service ps -ef |grep ftp systemctl list-unit-files|grep vsftpd 查看ssh开机自启动 systemctl enable sshd systemctl list-unit-files | grep ssh 查看ntp是否开机自启动 systemctl status ntpd systemctl list-unit-files |grep ntpd 安装telnet rpm -qa|grep telnet; yum -y install telnet-server; systemctl start telnet.socket; systemctl list-unit-files |grep telnet 创建用户 groupadd A useradd -d /home/nmb -m -g nmc -s /bin/bash hanjf chown hanjf:A /home/nmcuser echo xX9#a13Js85kd0Ayi2 | passwd hanjf --stdin -d指定用户主目录路径 -m如果路径不存在,将自动创建 -s指定默认shell java环境变量 #java environment export JAVA_HOME=/usr/local/jdk1.8.0_111 export CLASSPATH=.:${JAVA_HOME}/jre/lib/rt.jar:${JAVA_HOME}/lib/dt.jar:${JAVA_HOME}/lib/tools.jar export PATH=$PATH:${JAVA_HOME}/bin 最大文件打开数 * soft nofile 65535 * hard nofile 65535 echo "* soft nofile 65535" >> /etc/security/limits.conf echo "* hard nofile 65535" >> /etc/security/limits.conf * soft noproc 11000 * hard noproc 11000 * 代表针对所有用户 noproc 是代表最大进程数 nofile 是代表最大文件打开数 环境变量 历史记录配置 export HISTTIMEFORMAT="%F %T `whoami` #给history加上时间戳 echo 'export HISTTIMEFORMAT="%F %T `whoami` "' >> /etc/profile 系统空闲等待时长 export TMOUT=300