以httpd为例子：
| 指令名称 | centos 6 | centos 7 |
|---|---|---|
| 启动服务 | service httpd start | systemctl start httpd.service |
| 关闭服务 | service httpd stop | systemctl stop httpd.service |
| 重启服务 | service httpd restart | systemctl restart httpd.service |
| 查看服务状态 | service httpd status | systemctl status httpd.service |
| 设置服务开机启动 | chkconfig httpd on | systemctl enable httpd.service |
| 设置服务开机关闭 | chkconfig httpd off | systemctl disable httpd.service |
| 查看服务开机启动 | chkconfig –list | systemctl list-units –type=service |