Error: Connection activation failed: Device not managed by NetworkManager

在虚拟机中,启动eth0 网卡时报错:

Error: Connection activation failed: Device not managed by NetworkManager

于是在网上找了解决方法:
Remove Network Manager from startup Services.

chkconfig NetworkManager off

Add Default Net Manager.

chkconfig network on

Stop NetworkManager first.

service NetworkManager stop

and then start Default Manager.

service network start

or you can change it easy:

system-config-network

uncheck the box that sets the eth0 as managed by NetworkManager and set IP info from there.

system-config-services

stop and disable NetworkManager , start and enable network.
you have problem because both of NetworkManager and Network using same Network driver and default network blocking access for NetworkManager. if you disable NetworkManager your problem will disappeared after restart.

结果还是有错:

service network Start

报错:

*出环回接口: [确定]
*出界面 eth0:
正在决定 eth0 的 IP 信息...失败了.
[失败]
RTNETLINK answers: File exists
RTNETLINK answers: File exists
RTNETLINK answers: File exists
RTNETLINK answers: File exists
RTNETLINK answers: File exists
RTNETLINK answers: File exists
RTNETLINK answers: File exists
RTNETLINK answers: File exists
RTNETLINK answers: File exists

于是在restart network一下,就OK了,不知道什么原理.