device lo not available because device is strictly unmanaged

我的系统是CentOS 7 内核版本 3.10
启动时发现网络没有起来，重启网络时报错：systemctl restart nertwork

使用journalctl -u network 查看Unit network的日志记录：

6月 07 09:44:24 centos7 systemd[1]: Starting LSB: Bring up/down networking...
6月 07 09:44:25 centos7 network[1596]: 正在打开环回接口： [  确定  ]
6月 07 09:44:25 centos7 network[1596]: 正在打开接口 ens32： 错误：连接激活失败：No suitable device found for this connection (device lo not available because device is strictly unmanaged).
6月 07 09:44:25 centos7 network[1596]: [失败]
6月 07 09:44:25 centos7 network[1596]: RTNETLINK answers: File exists
6月 07 09:44:25 centos7 network[1596]: RTNETLINK answers: File exists
6月 07 09:44:25 centos7 network[1596]: RTNETLINK answers: File exists
6月 07 09:44:25 centos7 network[1596]: RTNETLINK answers: File exists
6月 07 09:44:25 centos7 network[1596]: RTNETLINK answers: File exists
6月 07 09:44:25 centos7 network[1596]: RTNETLINK answers: File exists
6月 07 09:44:25 centos7 network[1596]: RTNETLINK answers: File exists
6月 07 09:44:25 centos7 network[1596]: RTNETLINK answers: File exists
6月 07 09:44:25 centos7 network[1596]: RTNETLINK answers: File exists
6月 07 09:44:25 centos7 systemd[1]: network.service: control process exited, code=exited status=1
6月 07 09:44:25 centos7 systemd[1]: Failed to start LSB: Bring up/down networking.
6月 07 09:44:25 centos7 systemd[1]: Unit network.service entered failed state.
6月 07 09:44:25 centos7 systemd[1]: network.service failed.

解决办法：关闭NetworkManager
systemctl stop NetworkManager
systemctl disable NetWorkManager

再次重启网络：
systemctl restart network