CentOS重启网卡出错：

执行 service network restart
出现错误： em1 because device is strictly unmanaged

解决办法：

[root@dxlceshicentos7 ~]# chkconfig NetworkManager off
Note: Forwarding request to ‘systemctl disable NetworkManager.service’.
Removed symlink /etc/systemd/system/multi-user.target.wants/NetworkManager.service.
Removed symlink /etc/systemd/system/dbus-org.freedesktop.NetworkManager.service.
Removed symlink /etc/systemd/system/dbus-org.freedesktop.nm-dispatcher.service.
Removed symlink /etc/systemd/system/network-online.target.wants/NetworkManager-wait-online.service.

[root@dxlceshicentos7 ~]# chkconfig network on

[root@dxlceshicentos7 ~]# service NetworkManager stop
Redirecting to /bin/systemctl stop NetworkManager.service

[root@dxlceshicentos7 ~]# service network start
Starting network (via systemctl): [ OK ]

示例：

步骤：

chkconfig NetworkManager off
chkconfig network on
service NetworkManager stop
service network start