virtualbox复制了虚拟机，重新初始化网卡后，需要对/etc/sysconfig/network-scripts/ifcfg-eth0更新UUID值，虽然不改暂时也没发现有问题。
网上查找需要nmcli工具进行查看。
1.首先我们查看一下nmcli是哪个软件包提供的
[root@localhost ~]# yum provides "*/nmcli" Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: mirrors.163.com * extras: mirrors.163.com * updates: mirrors.163.com 1:NetworkManager-0.8.1-113.el6.x86_64 : Network connection manager and user applications Repo : base Matched from: Filename : /usr/bin/nmcli
2.安装NetworkManager服务
[root@localhost ~]# yum -y install NetworkManager
启动NetworkManager服务
[root@localhost ~]# /etc/init.d/NetworkManager start
运行nmcli发现有报错
[root@localhost ~]# nmcli con Error: could not connect to D-Bus.
查看/var/log/messages日志
[root@localhost ~]# more /var/log/messages ... Apr 20 14:53:05 localhost NetworkManager[2013]: <info> NetworkManager (version 0.8.1-113.el6) is starting... Apr 20 14:53:05 localhost NetworkManager[2013]: <info> Read config file /etc/NetworkManager/NetworkManager.conf Apr 20 14:53:05 localhost NetworkManager[2013]: <error> [1492671185.606620] [nm-dbus-manager.c:278] nm_dbus_manager_init_bus(): Could not get the system bus. Make sure the message bus daemon is running! Message: Failed to connect to socket /var/run/dbus/system_bus_socket: Connection refused ...
3.需要先启动messagebus，再启动NetworkManager
[root@localhost ~]# /etc/init.d/messagebus start Starting system message bus: [ OK ] [root@localhost ~]# /etc/init.d/NetworkManager start Setting network parameters... [ OK ] Starting NetworkManager daemon: [ OK ]
4.此时再运行nmcli即可查看网卡UUID
[root@localhost ~]# nmcli con NAME UUID TYPE SCOPE TIMESTAMP-REAL System eth0 bbc0e340-6979-4e10-8b98-f1d395e7304e 802-3-ethernet system Thu 20 Apr 2017 02:54:51 PM CST NAME UUID TYPE SCOPE TIMESTAMP-REAL
来源：https://www.cnblogs.com/hjfeng1988/p/6738778.html