以Apache Httpd为例
①某服务自动启动
旧 → chkconfig --level 3 httpd on
新 → systemctl enable httpd.service
②使某服务不自动启动
旧 → chkconfig --level 3 httpd off
新 → systemctl disable httpd.service
③检查服务状态
旧 → service httpd status（服务详细信息）
新 → systemctl status httpd.service 或 journalctl -xn（服务详细信息）
systemctl is-active httpd.service （仅显示是否 Active)
④显示所有已启动的服务
旧 → chkconfig --list
新 → systemctl list-units --type=service
⑤启动某服务
旧 → service httpd start
新 → systemctl start httpd.service
⑥停止某服务
旧 → service httpd stop
新 → systemctl stop httpd.service
⑦重启某服务
旧 → service httpd restart
新 → systemctl restart httpd.service